Valeria Rodriguez | Universidad Nacional de Córdoba (original) (raw)
Papers by Valeria Rodriguez
Applied Physiology, Nutrition, and Metabolism
We analyzed the effect of naringin (NAR), a flavonoid from citric fruits, on bone quality and bio... more We analyzed the effect of naringin (NAR), a flavonoid from citric fruits, on bone quality and biomechanical properties, as well as the redox state of bone marrow in rats fed a fructose-rich diet (FRD), an experimental model to mimic human metabolic syndrome. NAR blocked the increase in the number of osteoclasts and adipocytes and the decrease in the number of osteocytes and osteocalcin (+) cells caused by FRD. Trabecular number was significantly higher in the FRD+NAR group. FRD induced a decrease in the femoral trabecular and cortical bone mineral density, which was blocked by NAR. The fracture and ultimate loads were also decreased in the FRD and FRD+NAR groups. NAR increased the number of nodes to terminal trabecula, the number of nodes to node trabecula, the number of nodes, and the number of nodes with 2 terminals and decreased the Dist (mean size of branches) value. FRD decreased bone marrow catalase activity, an effect that was prevented by NAR. In conclusion, FRD has detrimen...
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie, Jan 24, 2017
Calcitriol (D) or 1,25(OH)2D3 inhibits the growth of several tumor cells including breast cancer ... more Calcitriol (D) or 1,25(OH)2D3 inhibits the growth of several tumor cells including breast cancer cells, by activating cell death pathways. Menadione (MEN), a glutathione-depleting compound, may be used to potentiate the antiproliferative actions of D on cancer cells. We have previously shown in vitro that MEN improved D-induced growth arrest on breast cancer cell lines, inducing oxidative stress and DNA damage via ROS generation. Treatment with MEN+D resulted more effective than D or MEN alone. To study the in vivo effect of calcitriol, MEN or their combination on the development of murine transplantable triple negative breast tumor M-406 in its syngeneic host. Tumor M-406 was inoculated s.c., and when tumors reached the desired size, animals were randomly assigned to one of four groups receiving daily i.p. injections of either sterile saline solution (controls, C), MEN, D, or both (MEN+D). Body weight and tumor volume were recorded three times a week. Serum calcium was determined b...
Biochemistry and cell biology = Biochimie et biologie cellulaire, 2017
LCA and 1,25(OH)2D3 are vitamin D receptor ligands with different binding affinity. The secostero... more LCA and 1,25(OH)2D3 are vitamin D receptor ligands with different binding affinity. The secosteroid stimulates intestinal Ca(2+) absorption. Whether LCA alters this process remains unknown. The aim of our work was to determine the effect of LCA on intestinal Ca(2+) absorption in the absence or presence of NaDOC, bile acid that inhibits the cation transport. The data show that LCA by itself did not alter intestinal Ca(2+) absorption, but prevented the inhibitory effect of NaDOC. The concomitant administration of LCA avoided the reduction of intestinal alkaline phosphatase activity caused by NaDOC. In addition, LCA blocked a decrease caused by NaDOC on gene and protein expression of molecules involved in the transcellular pathway of intestinal Ca(2+) absorption. The oxidative stress and apoptosis triggered by NaDOC were abrogated by LCA co-treatment. In conclusion, LCA placed in the intestinal lumen protects intestinal Ca(2+) absorption against the inhibitory effects caused by NaDOC. ...
Mastozoologia Neotropical, 2010
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology, 2016
We have previously demonstrated that melatonin (MEL) blocks the inhibition of the intestinal Ca(2... more We have previously demonstrated that melatonin (MEL) blocks the inhibition of the intestinal Ca(2+) absorption caused by menadione (MEN). The purpose of this study were to determine whether MEL not only restores but also prevents the intestinal Ca(2+) absorption inhibited either by MEN or BSO, two drugs that deplete glutathione (GSH) in different ways, and to analyze the mechanisms by which MEN and MEL alter the movement of Ca(2+) across the duodenum. To know this, chicks were divided into four groups: 1) controls, 2) MEN treated, 3) MEL treated, and 4) treated sequentially with MEN and MEL or with MEN and MEL at the same time. In a set of experiments, chicks treated with BSO or sequentially with BSO and MEL or with BSO and MEL at the same time were used. MEL not only restored but also prevented the inhibition of the chick intestinal Ca(2+) absorption produced by either MEN or BSO. MEN altered the protein expression of molecules involved in the transcellular as well as in the parace...
Archives of Biochemistry and Biophysics, 2016
The aim of this work was to study the effect of sodium deoxycholate (NaDOC) and ursodeoxycholic a... more The aim of this work was to study the effect of sodium deoxycholate (NaDOC) and ursodeoxycholic acid (UDCA) on Ca(2+) uptake by enterocytes and the underlying mechanisms. Rats were divided into four groups: a) controls, b) treated with NaDOC, c) treated with UDCA d) treated with NaDOC and UDCA. Ca(2+) uptake was studied in enterocytes with different degrees of maturation. Apoptosis, autophagy and NO content and iNOS protein expression were evaluated. NaDOC decreased and UDCA increased Ca(2+) uptake only in mature enterocytes. The enhancement of protein expression of Fas, FasL, caspase-8 and caspase-3 activity by NaDOC indicates triggering of the apoptotic extrinsic pathway, which was blocked by UDCA. NO content and iNOS protein expression were enhanced by NaDOC, and avoided by UDCA. The increment of acidic vesicular organelles and LC3 II produced by NaDOC was also prevented by UDCA. In conclusion, the inhibitory effects of NaDOC on intestinal Ca(2+) absorption occur by decreasing the Ca(2+) uptake by mature enterocytes. NaDOC triggers apoptosis and autophagy, in part as a result of nitrosative stress. In contrast, UDCA increases the Ca(2+) uptake by mature enterocytes, and in combination with NaDOC acts as an antiapoptotic and antiautophagic agent normalizing the transcellular Ca(2+) pathway.
Mastozoologia Neotropical, Jun 1, 2007
... provincia del Chubut, las siguientes especies: Abrothrix olivaceus, Eligmodontia sp., Euneomy... more ... provincia del Chubut, las siguientes especies: Abrothrix olivaceus, Eligmodontia sp., Euneomys chinchilloides, Graomys griseoflavus, Lestodelphys halli, Microcavia australis, Phyllotis xanthopygus, Reithrodon auritus y Thylamys sp. ... Graomys griseoflavus (Waterhouse, 1837). ...
Nutrition Research Reviews, 2015
The intestine is the only gate for the entry of Ca to the body in humans and mammals. The entranc... more The intestine is the only gate for the entry of Ca to the body in humans and mammals. The entrance of Ca occurs via paracellular and intracellular pathways. All steps of the latter pathway are regulated by calcitriol and by other hormones. Dietary and pharmacological compounds also modulate the intestinal Ca absorption process. Among them, dietary Ca and P are known to alter the lipid and protein composition of the brush-border and basolateral membranes and, consequently, Ca transport. Ca intakes are below the requirements recommended by health professionals in most countries, triggering important health problems. Chronic low Ca intake has been related to illness conditions such as osteoporosis, hypertension, renal lithiasis and incidences of human cancer. Carbohydrates, mainly lactose, and prebiotics have been described as positive modulators of intestinal Ca absorption. Apparently, high meat proteins increase intestinal Ca absorption while the effect of dietary lipids remains uncl...
Publikationsansicht. 22204509. Determinación específica y niveles de polimorfismo alozímico de Gr... more Publikationsansicht. 22204509. Determinación específica y niveles de polimorfismo alozímico de Graomys (Rodentia, Muridae) de los alrededores de Comodoro Rivadavia (2006). Valeria Andrea Rodríguez. Abstract. Determinación ...
Revista de la Facultad de Ciencias Médicas (Córdoba, Argentina)
Calcium is essential for bone and tooth formation, achievement of optimal peak bone mass and also... more Calcium is essential for bone and tooth formation, achievement of optimal peak bone mass and also for regulation of physiological processes. The calcium demand depends on age, gender and different physiological processes. These requirements are higher during childhood, pregnancy and lactation. Dietary Ca2+ deficiency modifies Ca2+ homeostasis and the metabolism of calciotropic hormones and increases the efficiency of intestinal Ca2+ absorption and renal reabsorption, altering bone metabolism. The low Ca2+ diet is associated with hypertension and risk of cancer.
Biochimica et biophysica acta, 2015
The aim was to determine the intestinal Ca(2+) absorption in type I diabetic rats after different... more The aim was to determine the intestinal Ca(2+) absorption in type I diabetic rats after different times of STZ induction, as well as the gene and protein expression of molecules involved in both the transcellular and paracellular Ca(2+) pathways. The redox state and the antioxidant enzymes of the enterocytes were also evaluated in duodenum from either diabetic or insulin-treated diabetic rats as compared to control rats. Male Wistar rats (150-200g) were divided into two groups: 1) controls and 2) STZ-induced diabetic rats (60mg/kg b.w.). A group of diabetic rats received insulin for five days. The insulin was adjusted daily to maintain a normal blood glucose level. Five 5 d after STZ injection, there was a reduction in the intestinal Ca(2+) absorption, which was maintained for 30 d and disappeared at 60 d. Similar changes occurred in the GSH and (˙)O2(-) levels. The protein expression of molecules involved in the transcellular pathway increased at 5 and 30 d returning to control val...
Acta Histochemica, 2014
Spermatogenesis is disrupted in Graomys griseoflavus×Graomys centralis male hybrids. This study w... more Spermatogenesis is disrupted in Graomys griseoflavus×Graomys centralis male hybrids. This study was aimed to determine whether morphological alterations in Leydig cells from hybrids accompany the arrest of spermatogenesis and cell death of germ cells and whether apoptotic pathways are also involved in the response of these interstitial cells. We used three groups of 1-, 2- and 3-month-old male animals: (1) G. centralis, (2) G. griseoflavus and (3) hybrids obtained by crossing G. griseoflavus females with G. centralis males. Testicular ultrastructure was analyzed by transmission electron microscopy. TUNEL was studied using an in situ cell death detection kit and the expression of apoptotic molecules by immunohistochemistry. The data confirmed arrest of spermatogenesis and intense apoptotic processes of germ cells in hybrids. These animals also showed ultrastructural alterations in the Leydig cells. Fas, FasL and calbindin D28k overexpression without an increase in DNA fragmentation was detected in the Leydig cells from hybrids. In conclusion, the sterility of Graomys hybrids occurs with ultrastructural changes in germ and Leydig cells. The enhancement of Fas and FasL is not associated with cell death in the Leydig cells. Probably the apoptosis in these interstitial cells is inhibited by the high expression of the antiapoptotic molecule calbindin D28k.
Reproduction, Fertility and Development, 2010
Spermatogenic impairment and the apoptotic pathways involved in establishing sterility of male hy... more Spermatogenic impairment and the apoptotic pathways involved in establishing sterility of male hybrids obtained from crossing Graomys griseoflavus females with Graomys centralis males were studied. Testes from G. centralis, G. griseoflavus and hybrids were compared at different ages. Terminal transferase-mediated dUTP nick-end labelling assay (TUNEL), Fas, Bax and cytochrome c labelling were used for apoptosis evaluation, and calbindin D(28k) staining as an anti-apoptotic molecule. In 1-month-old animals, spermatocytes were positive for all apoptotic markers, but moderate TUNEL (+) spermatocyte frequency was only found in G. centralis. At subsequent ages, the apoptotic markers were downregulated in testes from parental cytotypes, but not in hybrid testes. TUNEL (+) spermatocytes were present at 78% and 44% per tubule cross-section in 2- and 3-month-old hybrid animals, respectively. Pachytene spermatocyte death in adult hybrids occurs via apoptosis, as revealed by high caspase-3 expression. Calbindin was highly expressed in spermatocytes of adult hybrids, in which massive cell death occurs via apoptosis. Calbindin co-localisation with TUNEL or Fas, Bax and cytochrome c was very limited, suggesting an inverse regulation of calbindin and apoptotic markers. Hybrid sterility is due to breakdown of spermatogenesis at the pachytene spermatocyte stage. Both extrinsic and intrinsic pathways are involved in apoptosis of spermatocytes, which are the most sensitive cell type to apoptotic stimuli.
Reproduction, 2008
The aim of this study was to determine whether the intrinsic mechanism of apoptosis is involved i... more The aim of this study was to determine whether the intrinsic mechanism of apoptosis is involved in the death of germ cells in Robertsonian (Rb) heterozygous adult male mice. Testes from 5-month-old Rb heterozygous CD1!Milano II mice were obtained and compared with those from homozygous CD1 (2nZ40) and Milano II (2nZ24) mice. For histological evaluation of apoptosis, TUNEL labelling and immunohistochemistry were used to localise Bax and cytochrome c. Expression of calbindin D 28k (CB), an anti-apoptotic molecule, was also analysed by immunohistochemistry and immunoblotting. Testicular ultrastructure was visualised by electron microscopy. Morphology and cell associations were abnormal in the Rb heterozygous seminiferous epithelium. An intense apoptotic process was observed in tubules at stage XII, mainly in metaphase spermatocytes. Metaphase spermatocytes also showed Bax and cytochrome c redistributions. Mitochondria relocated close to the paranuclear region of spermatocytes. CB was mainly expressed in metaphase spermatocytes, but also in pachytene spermatocytes, spermatids and Sertoli cells at stage XII. The co-localisation of CB and TUNEL labelling was very limited. Sixty per cent of metaphase spermatocytes were apoptotic and calbindin negative, while 40% were calbindin positive without signs of apoptosis. Ten per cent of the Bax-and cytochrome c-positive cells were also calbindin positive. These data suggest that apoptosis of the germ cells in heterozygous mice occurs, at least in part, through a mitochondrial-dependent mechanism. Calbindin overexpression might prevent or reduce the apoptosis of germ cells caused by Rb heterozygosity, which could partially explain the subfertility of these mice.
Nutrition Research Reviews, 2009
Ca is not only essential for bone mineralisation, but also for regulation of extracellular and in... more Ca is not only essential for bone mineralisation, but also for regulation of extracellular and intracellular processes. When the Ca 2þ intake is low, the efficiency of intestinal Ca 2þ absorption and renal Ca 2þ reabsorption is increased. This adaptive mechanism involves calcitriol enhancement via parathyroid hormone stimulation. Bone is also highly affected. Low Ca 2þ intake is considered a risk factor for osteoporosis. Patients with renal lithiasis may be at higher risk of recurrence of stone formation when they have low Ca 2þ intake. The role of dietary Ca 2þ on the regulation of lipid metabolism and lipogenic genes in adipocytes might explain an inverse relationship between dairy intake and BMI. Dietary Ca 2þ restriction produces impairment of the adipocyte apoptosis and dysregulation of glucocorticosteroid metabolism in the adipose tissue. An inverse relationship between hypertension and a low-Ca 2þ diet has been described. Ca 2þ facilitates weight loss and stimulates insulin sensitivity, which contributes to the decrease in the blood pressure. There is also evidence that dietary Ca 2þ is associated with colorectal cancer. Dietary Ca 2þ could alter the ratio of faecal bile acids, reducing the cytotoxicity of faecal water, or it could activate Ca 2þ -sensing receptors, triggering intracellular signalling pathways. Also it could bind luminal antigens, transporting them into mucosal mononuclear cells as a mechanism of immunosurveillance and promotion of tolerance. Data relative to nutritional Ca 2þ and incidences of other human cancers are controversial. Health professionals should be aware of these nutritional complications and reinforce the dairy intakes to ensure the recommended Ca 2þ requirements and prevent diseases.
Mastozoología neotropical, 2007
Cancer Investigation, 2012
Calcitriol or 1,25(OH)(2)D(3) is a negative growth regulator of breast cancer cells. The aim of t... more Calcitriol or 1,25(OH)(2)D(3) is a negative growth regulator of breast cancer cells. The aim of this study was to determine whether L-buthionine-S,R-sulfoximine, a glutathione-depleting drug, modifies the antiproliferative effects of 1,25(OH)(2)D(3) on MCF-7 cells. For comparison, we included studies in MCF-7 cells selected for vitamin D resistance and in human mammary epithelial cells transformed with SV40 and ras. Our data indicate that L-buthionine-S,R-sulfoximine enhances the growth inhibition of 1,25(OH)(2)D(3) in all transformed breast cell lines. This effect is mediated by ROS leading to apoptosis. In conclusion, BSO alters redox state and sensitizes breast cancer cells to 1,25(OH)(2)D(3)-mediated apoptosis.
Applied Physiology, Nutrition, and Metabolism
We analyzed the effect of naringin (NAR), a flavonoid from citric fruits, on bone quality and bio... more We analyzed the effect of naringin (NAR), a flavonoid from citric fruits, on bone quality and biomechanical properties, as well as the redox state of bone marrow in rats fed a fructose-rich diet (FRD), an experimental model to mimic human metabolic syndrome. NAR blocked the increase in the number of osteoclasts and adipocytes and the decrease in the number of osteocytes and osteocalcin (+) cells caused by FRD. Trabecular number was significantly higher in the FRD+NAR group. FRD induced a decrease in the femoral trabecular and cortical bone mineral density, which was blocked by NAR. The fracture and ultimate loads were also decreased in the FRD and FRD+NAR groups. NAR increased the number of nodes to terminal trabecula, the number of nodes to node trabecula, the number of nodes, and the number of nodes with 2 terminals and decreased the Dist (mean size of branches) value. FRD decreased bone marrow catalase activity, an effect that was prevented by NAR. In conclusion, FRD has detrimen...
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie, Jan 24, 2017
Calcitriol (D) or 1,25(OH)2D3 inhibits the growth of several tumor cells including breast cancer ... more Calcitriol (D) or 1,25(OH)2D3 inhibits the growth of several tumor cells including breast cancer cells, by activating cell death pathways. Menadione (MEN), a glutathione-depleting compound, may be used to potentiate the antiproliferative actions of D on cancer cells. We have previously shown in vitro that MEN improved D-induced growth arrest on breast cancer cell lines, inducing oxidative stress and DNA damage via ROS generation. Treatment with MEN+D resulted more effective than D or MEN alone. To study the in vivo effect of calcitriol, MEN or their combination on the development of murine transplantable triple negative breast tumor M-406 in its syngeneic host. Tumor M-406 was inoculated s.c., and when tumors reached the desired size, animals were randomly assigned to one of four groups receiving daily i.p. injections of either sterile saline solution (controls, C), MEN, D, or both (MEN+D). Body weight and tumor volume were recorded three times a week. Serum calcium was determined b...
Biochemistry and cell biology = Biochimie et biologie cellulaire, 2017
LCA and 1,25(OH)2D3 are vitamin D receptor ligands with different binding affinity. The secostero... more LCA and 1,25(OH)2D3 are vitamin D receptor ligands with different binding affinity. The secosteroid stimulates intestinal Ca(2+) absorption. Whether LCA alters this process remains unknown. The aim of our work was to determine the effect of LCA on intestinal Ca(2+) absorption in the absence or presence of NaDOC, bile acid that inhibits the cation transport. The data show that LCA by itself did not alter intestinal Ca(2+) absorption, but prevented the inhibitory effect of NaDOC. The concomitant administration of LCA avoided the reduction of intestinal alkaline phosphatase activity caused by NaDOC. In addition, LCA blocked a decrease caused by NaDOC on gene and protein expression of molecules involved in the transcellular pathway of intestinal Ca(2+) absorption. The oxidative stress and apoptosis triggered by NaDOC were abrogated by LCA co-treatment. In conclusion, LCA placed in the intestinal lumen protects intestinal Ca(2+) absorption against the inhibitory effects caused by NaDOC. ...
Mastozoologia Neotropical, 2010
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology, 2016
We have previously demonstrated that melatonin (MEL) blocks the inhibition of the intestinal Ca(2... more We have previously demonstrated that melatonin (MEL) blocks the inhibition of the intestinal Ca(2+) absorption caused by menadione (MEN). The purpose of this study were to determine whether MEL not only restores but also prevents the intestinal Ca(2+) absorption inhibited either by MEN or BSO, two drugs that deplete glutathione (GSH) in different ways, and to analyze the mechanisms by which MEN and MEL alter the movement of Ca(2+) across the duodenum. To know this, chicks were divided into four groups: 1) controls, 2) MEN treated, 3) MEL treated, and 4) treated sequentially with MEN and MEL or with MEN and MEL at the same time. In a set of experiments, chicks treated with BSO or sequentially with BSO and MEL or with BSO and MEL at the same time were used. MEL not only restored but also prevented the inhibition of the chick intestinal Ca(2+) absorption produced by either MEN or BSO. MEN altered the protein expression of molecules involved in the transcellular as well as in the parace...
Archives of Biochemistry and Biophysics, 2016
The aim of this work was to study the effect of sodium deoxycholate (NaDOC) and ursodeoxycholic a... more The aim of this work was to study the effect of sodium deoxycholate (NaDOC) and ursodeoxycholic acid (UDCA) on Ca(2+) uptake by enterocytes and the underlying mechanisms. Rats were divided into four groups: a) controls, b) treated with NaDOC, c) treated with UDCA d) treated with NaDOC and UDCA. Ca(2+) uptake was studied in enterocytes with different degrees of maturation. Apoptosis, autophagy and NO content and iNOS protein expression were evaluated. NaDOC decreased and UDCA increased Ca(2+) uptake only in mature enterocytes. The enhancement of protein expression of Fas, FasL, caspase-8 and caspase-3 activity by NaDOC indicates triggering of the apoptotic extrinsic pathway, which was blocked by UDCA. NO content and iNOS protein expression were enhanced by NaDOC, and avoided by UDCA. The increment of acidic vesicular organelles and LC3 II produced by NaDOC was also prevented by UDCA. In conclusion, the inhibitory effects of NaDOC on intestinal Ca(2+) absorption occur by decreasing the Ca(2+) uptake by mature enterocytes. NaDOC triggers apoptosis and autophagy, in part as a result of nitrosative stress. In contrast, UDCA increases the Ca(2+) uptake by mature enterocytes, and in combination with NaDOC acts as an antiapoptotic and antiautophagic agent normalizing the transcellular Ca(2+) pathway.
Mastozoologia Neotropical, Jun 1, 2007
... provincia del Chubut, las siguientes especies: Abrothrix olivaceus, Eligmodontia sp., Euneomy... more ... provincia del Chubut, las siguientes especies: Abrothrix olivaceus, Eligmodontia sp., Euneomys chinchilloides, Graomys griseoflavus, Lestodelphys halli, Microcavia australis, Phyllotis xanthopygus, Reithrodon auritus y Thylamys sp. ... Graomys griseoflavus (Waterhouse, 1837). ...
Nutrition Research Reviews, 2015
The intestine is the only gate for the entry of Ca to the body in humans and mammals. The entranc... more The intestine is the only gate for the entry of Ca to the body in humans and mammals. The entrance of Ca occurs via paracellular and intracellular pathways. All steps of the latter pathway are regulated by calcitriol and by other hormones. Dietary and pharmacological compounds also modulate the intestinal Ca absorption process. Among them, dietary Ca and P are known to alter the lipid and protein composition of the brush-border and basolateral membranes and, consequently, Ca transport. Ca intakes are below the requirements recommended by health professionals in most countries, triggering important health problems. Chronic low Ca intake has been related to illness conditions such as osteoporosis, hypertension, renal lithiasis and incidences of human cancer. Carbohydrates, mainly lactose, and prebiotics have been described as positive modulators of intestinal Ca absorption. Apparently, high meat proteins increase intestinal Ca absorption while the effect of dietary lipids remains uncl...
Publikationsansicht. 22204509. Determinación específica y niveles de polimorfismo alozímico de Gr... more Publikationsansicht. 22204509. Determinación específica y niveles de polimorfismo alozímico de Graomys (Rodentia, Muridae) de los alrededores de Comodoro Rivadavia (2006). Valeria Andrea Rodríguez. Abstract. Determinación ...
Revista de la Facultad de Ciencias Médicas (Córdoba, Argentina)
Calcium is essential for bone and tooth formation, achievement of optimal peak bone mass and also... more Calcium is essential for bone and tooth formation, achievement of optimal peak bone mass and also for regulation of physiological processes. The calcium demand depends on age, gender and different physiological processes. These requirements are higher during childhood, pregnancy and lactation. Dietary Ca2+ deficiency modifies Ca2+ homeostasis and the metabolism of calciotropic hormones and increases the efficiency of intestinal Ca2+ absorption and renal reabsorption, altering bone metabolism. The low Ca2+ diet is associated with hypertension and risk of cancer.
Biochimica et biophysica acta, 2015
The aim was to determine the intestinal Ca(2+) absorption in type I diabetic rats after different... more The aim was to determine the intestinal Ca(2+) absorption in type I diabetic rats after different times of STZ induction, as well as the gene and protein expression of molecules involved in both the transcellular and paracellular Ca(2+) pathways. The redox state and the antioxidant enzymes of the enterocytes were also evaluated in duodenum from either diabetic or insulin-treated diabetic rats as compared to control rats. Male Wistar rats (150-200g) were divided into two groups: 1) controls and 2) STZ-induced diabetic rats (60mg/kg b.w.). A group of diabetic rats received insulin for five days. The insulin was adjusted daily to maintain a normal blood glucose level. Five 5 d after STZ injection, there was a reduction in the intestinal Ca(2+) absorption, which was maintained for 30 d and disappeared at 60 d. Similar changes occurred in the GSH and (˙)O2(-) levels. The protein expression of molecules involved in the transcellular pathway increased at 5 and 30 d returning to control val...
Acta Histochemica, 2014
Spermatogenesis is disrupted in Graomys griseoflavus×Graomys centralis male hybrids. This study w... more Spermatogenesis is disrupted in Graomys griseoflavus×Graomys centralis male hybrids. This study was aimed to determine whether morphological alterations in Leydig cells from hybrids accompany the arrest of spermatogenesis and cell death of germ cells and whether apoptotic pathways are also involved in the response of these interstitial cells. We used three groups of 1-, 2- and 3-month-old male animals: (1) G. centralis, (2) G. griseoflavus and (3) hybrids obtained by crossing G. griseoflavus females with G. centralis males. Testicular ultrastructure was analyzed by transmission electron microscopy. TUNEL was studied using an in situ cell death detection kit and the expression of apoptotic molecules by immunohistochemistry. The data confirmed arrest of spermatogenesis and intense apoptotic processes of germ cells in hybrids. These animals also showed ultrastructural alterations in the Leydig cells. Fas, FasL and calbindin D28k overexpression without an increase in DNA fragmentation was detected in the Leydig cells from hybrids. In conclusion, the sterility of Graomys hybrids occurs with ultrastructural changes in germ and Leydig cells. The enhancement of Fas and FasL is not associated with cell death in the Leydig cells. Probably the apoptosis in these interstitial cells is inhibited by the high expression of the antiapoptotic molecule calbindin D28k.
Reproduction, Fertility and Development, 2010
Spermatogenic impairment and the apoptotic pathways involved in establishing sterility of male hy... more Spermatogenic impairment and the apoptotic pathways involved in establishing sterility of male hybrids obtained from crossing Graomys griseoflavus females with Graomys centralis males were studied. Testes from G. centralis, G. griseoflavus and hybrids were compared at different ages. Terminal transferase-mediated dUTP nick-end labelling assay (TUNEL), Fas, Bax and cytochrome c labelling were used for apoptosis evaluation, and calbindin D(28k) staining as an anti-apoptotic molecule. In 1-month-old animals, spermatocytes were positive for all apoptotic markers, but moderate TUNEL (+) spermatocyte frequency was only found in G. centralis. At subsequent ages, the apoptotic markers were downregulated in testes from parental cytotypes, but not in hybrid testes. TUNEL (+) spermatocytes were present at 78% and 44% per tubule cross-section in 2- and 3-month-old hybrid animals, respectively. Pachytene spermatocyte death in adult hybrids occurs via apoptosis, as revealed by high caspase-3 expression. Calbindin was highly expressed in spermatocytes of adult hybrids, in which massive cell death occurs via apoptosis. Calbindin co-localisation with TUNEL or Fas, Bax and cytochrome c was very limited, suggesting an inverse regulation of calbindin and apoptotic markers. Hybrid sterility is due to breakdown of spermatogenesis at the pachytene spermatocyte stage. Both extrinsic and intrinsic pathways are involved in apoptosis of spermatocytes, which are the most sensitive cell type to apoptotic stimuli.
Reproduction, 2008
The aim of this study was to determine whether the intrinsic mechanism of apoptosis is involved i... more The aim of this study was to determine whether the intrinsic mechanism of apoptosis is involved in the death of germ cells in Robertsonian (Rb) heterozygous adult male mice. Testes from 5-month-old Rb heterozygous CD1!Milano II mice were obtained and compared with those from homozygous CD1 (2nZ40) and Milano II (2nZ24) mice. For histological evaluation of apoptosis, TUNEL labelling and immunohistochemistry were used to localise Bax and cytochrome c. Expression of calbindin D 28k (CB), an anti-apoptotic molecule, was also analysed by immunohistochemistry and immunoblotting. Testicular ultrastructure was visualised by electron microscopy. Morphology and cell associations were abnormal in the Rb heterozygous seminiferous epithelium. An intense apoptotic process was observed in tubules at stage XII, mainly in metaphase spermatocytes. Metaphase spermatocytes also showed Bax and cytochrome c redistributions. Mitochondria relocated close to the paranuclear region of spermatocytes. CB was mainly expressed in metaphase spermatocytes, but also in pachytene spermatocytes, spermatids and Sertoli cells at stage XII. The co-localisation of CB and TUNEL labelling was very limited. Sixty per cent of metaphase spermatocytes were apoptotic and calbindin negative, while 40% were calbindin positive without signs of apoptosis. Ten per cent of the Bax-and cytochrome c-positive cells were also calbindin positive. These data suggest that apoptosis of the germ cells in heterozygous mice occurs, at least in part, through a mitochondrial-dependent mechanism. Calbindin overexpression might prevent or reduce the apoptosis of germ cells caused by Rb heterozygosity, which could partially explain the subfertility of these mice.
Nutrition Research Reviews, 2009
Ca is not only essential for bone mineralisation, but also for regulation of extracellular and in... more Ca is not only essential for bone mineralisation, but also for regulation of extracellular and intracellular processes. When the Ca 2þ intake is low, the efficiency of intestinal Ca 2þ absorption and renal Ca 2þ reabsorption is increased. This adaptive mechanism involves calcitriol enhancement via parathyroid hormone stimulation. Bone is also highly affected. Low Ca 2þ intake is considered a risk factor for osteoporosis. Patients with renal lithiasis may be at higher risk of recurrence of stone formation when they have low Ca 2þ intake. The role of dietary Ca 2þ on the regulation of lipid metabolism and lipogenic genes in adipocytes might explain an inverse relationship between dairy intake and BMI. Dietary Ca 2þ restriction produces impairment of the adipocyte apoptosis and dysregulation of glucocorticosteroid metabolism in the adipose tissue. An inverse relationship between hypertension and a low-Ca 2þ diet has been described. Ca 2þ facilitates weight loss and stimulates insulin sensitivity, which contributes to the decrease in the blood pressure. There is also evidence that dietary Ca 2þ is associated with colorectal cancer. Dietary Ca 2þ could alter the ratio of faecal bile acids, reducing the cytotoxicity of faecal water, or it could activate Ca 2þ -sensing receptors, triggering intracellular signalling pathways. Also it could bind luminal antigens, transporting them into mucosal mononuclear cells as a mechanism of immunosurveillance and promotion of tolerance. Data relative to nutritional Ca 2þ and incidences of other human cancers are controversial. Health professionals should be aware of these nutritional complications and reinforce the dairy intakes to ensure the recommended Ca 2þ requirements and prevent diseases.
Mastozoología neotropical, 2007
Cancer Investigation, 2012
Calcitriol or 1,25(OH)(2)D(3) is a negative growth regulator of breast cancer cells. The aim of t... more Calcitriol or 1,25(OH)(2)D(3) is a negative growth regulator of breast cancer cells. The aim of this study was to determine whether L-buthionine-S,R-sulfoximine, a glutathione-depleting drug, modifies the antiproliferative effects of 1,25(OH)(2)D(3) on MCF-7 cells. For comparison, we included studies in MCF-7 cells selected for vitamin D resistance and in human mammary epithelial cells transformed with SV40 and ras. Our data indicate that L-buthionine-S,R-sulfoximine enhances the growth inhibition of 1,25(OH)(2)D(3) in all transformed breast cell lines. This effect is mediated by ROS leading to apoptosis. In conclusion, BSO alters redox state and sensitizes breast cancer cells to 1,25(OH)(2)D(3)-mediated apoptosis.