Gilberto Sanvitto - Academia.edu (original) (raw)

Papers by Gilberto Sanvitto

Objetivos: Evaluar el efecto de la ingesta calorica y el refresco sin calorias en el consumo de a... more Objetivos: Evaluar el efecto de la ingesta calorica y el refresco sin calorias en el consumo de alimentos, el peso corporal y la composicion, y los parametros metabolicos en las ratas. Metodos: estudio experimental controlado en el que 30 ratas macho Wistar se dividieron en tres grupos y se les da comida y bebida ad libitum durante 17 semanas. Los grupos fueron los siguientes, de acuerdo con la comida que se ofrece: Grupo de control - pienso estandar y agua; Calorica grupo de refrescos - comida estandar, refrescos de calorias, y agua; y no calorico grupo de refrescos - comida estandar, refresco sin calorias y agua. Resultados: No hubo diferencia estadisticamente significativa en la ingesta total de energia, el peso corporal, y la deposicion de grasa entre los grupos. Sin embargo, la ingesta de energia Chow era 45% menor en el grupo de refrescos de calorias en comparacion con los grupos de refrescos de control y no caloricos (198,7 ± 0,7 vs. 349,4 kJ ± 2,0 y 373,0 ± 1,3 kJ, respectiv...

Clinical & Biomedical Research

Introduction: Important changes in human dietary pattern occurred in recent decades. Increased in... more Introduction: Important changes in human dietary pattern occurred in recent decades. Increased intake of processed foods leads to obesity, which is related with the development of chronic diseases such as type 2 diabetes mellitus, hypertension, as well as cardiovascular and chronic kidney diseases. The prevalence of hypertension has also dramatically increased in recent years, and high sodium intake contributes to this scenario. In healthy individuals, kidneys are the primary end-organs that regulate sodium homeostasis. This study aims to evaluate renal function parameters and systolic blood pressure measurements in an animal model of obesity. Methods: Sixty-day-old male Wistar rats (n=30) were divided into two groups: standard (SD) and cafeteria diet (CD). Cafeteria diet was altered daily and was composed by crackers, wafers, sausages, chips, condensed milk, and soda. All animals had free access to water and chow and the experiment was carried out for 6 weeks. Weight gain, sodium and liquid intake control, systolic blood pressure measurements, and renal function parameters were evaluated. Results: Animals exposed to cafeteria diet had an increase of 18% in weight compared to the control group. Sodium intake was increased by cafeteria diet and time (F (1,28) =773.666, P=0.001 and F (5,28) =2.859, P=0.02, respectively) and by the interaction of both factors (F (6,28) =2.859, P=0.02). On liquid intake occurred only effect of cafeteria diet and time (F (1,28) =147.04, P=0.001 and F (5,28) =3.996, P=0.003, respectively). Cafeteria diet exposure also induced an increase on creatinine serum levels (P=0.002), however this effect was not observed on creatinine urine levels (P>0.05) nor on systolic pressure measurements (Students' t test, P>0.05). Conclusions: Obesity induced by cafeteria diet exposure increases liquid intake and alters creatinine serum levels, an important renal function marker. Considering the high consumption of hypercaloric food currently in the world, further studies are required to elucidate the modifications on renal function triggered by this diet over time.

J Endocrinol, 2006

We have previously shown that the locus coeruleus (LC) is essential for triggering surges of LH. ... more We have previously shown that the locus coeruleus (LC) is essential for triggering surges of LH. Since LC neurons are responsive to estradiol, which induces progesterone receptor (PR) expression, this study aimed to investigate whether LC neurons express the-estradiol receptor (ER) and PR as well as comparing such responses to that observed in the preoptic area (POA). Female rats were perfused at 10, 14 and 16 h on each day of the estrous cycle, and a blood sample was collected for estradiol, progesterone and LH measurements. ER-and PR immunoreactive (ir) neurons were detected in POA and LC by immunocytochemistry (ICC). Higher plasma estradiol levels were observed on the day of proestrus, when a smaller number of ER-ir POA neurons were detected. An increase in the number of ER-ir neurons were observed at 16 h of proestrus and estrus. The number of PR-ir neurons increased in POA only at 16 h of proestrus, and remained unchanged during all other days and times. The profile of ER-ir and PR-ir neurons in LC changed over the estrous cycle, with a lower expression on metestrus morning and reaching a peak on diestrus afternoon before declining on the day of proestrus. However, on estrus afternoon, ER-ir neurons increased, while PR-ir neurons decreased which may be related to the prolactin surge of estrus. These data show that LC neurons express ER and PR and seem to be more sensitive to variations in estradiol than POA. Also, the fluctuation in ER and PR observed for LC neurons seems to accompany the hormonal events that occur during the estrous cycle. This profile of ER and PR expression might be related to the ability of estradiol and progesterone in regulating the activity of LC neurons, which could be associated to the control mechanisms of LH and prolactin release.

A estimulação neonatal é utilizada como modelo experimental para examinar os mecanismos pelos qua... more A estimulação neonatal é utilizada como modelo experimental para examinar os mecanismos pelos quais variações precoces do ambiente do animal afetam o desenvolvimento de sistemas neurais dando origem a alterações comportamentais e neuroendócrinas estáveis. Este trabalho teve como objetivo verificar o efeito da estimulação neonatal sobre a ingestão hídrica (IH) basal e induzida pela angiotensina II (Ang II) em ratos adultos. Ratos Wistar machos (♂) (n=28) e fêmeas (♀) (n=29) foram divididos em 2 grupos ao nascer: Intacto (I), sem intervenção; e Manipulado (M), submetido a estímulo manual 1 min/dia durante os 10 primeiros dias de vida. Aos 100 dias foi medida a IH basal (mL/h) nos ♂ seguida da implantação de uma cânula intracerebroventricular aonde foi administrado Ang II (5µg/2µl) seguido da medida da latência (s) (tempo decorrido entre a microinjeção de Ang II e o início do comportamento de beber água) e IH (mL/h). As ♀ sofreram os mesmos procedimentos com a diferença que a partir 100 dias de idade a medida da IH basal foi acompanhada da análise da fase do ciclo estral através de esfregaço vaginal. Não houve diferença na IH das ♀ dos grupos I e M nas diferentes fases do ciclo. Tanto os ♂ quanto as ♀ do grupo M apresentaram um aumento na IH basal (mL/h): ♂(I=1,72±0,04; M=2,03± 0,10) e ♀(I=0,90±0,08; M=1,25±0,08) p≤0,05. Não houve diferença na IH induzida entre os grupos I e M tanto em ♂ quanto em ♀. Houve uma diminuição da latência da IH induzida em ♂(I=35±10;M=12±4) p≤0,01 e uma tendência à diminuição nas ♀(I=28±10;M=11±1) não significativa. Esses resultados indicam que a estimulação neonatal induz a efeitos tardios sobre o comportamento de IH e que esses efeitos podem ser mediados pelo sistema angiotensinérgico cerebral.

Physiology Behavior, Nov 23, 2007

Physical or emotional stress can affect the female reproductive physiology and angiotensin II (An... more Physical or emotional stress can affect the female reproductive physiology and angiotensin II (Ang II) is a hormone that participates in the stress response and also in the control of reproductive hormones. The present study aimed at evaluating the effects of acute stress in the morning and afternoon of proestrus on sexual behavior and ovulation and the participation of Ang II in the stress-induced effects. Female rats with regular estrous cycles were used. Several different stress protocols were tested in the morning and in the afternoon of proestrus: restraint stress 10 min; restraint stress 1 h and ether stress, respectively. The participation of Ang II was evaluated by injecting Ang II receptor antagonists (losartan and PD123319) 15 min before stress. The lordosis quotient was recorded and the number of oocytes was counted. Plasma levels of luteinizing hormone, progesterone, prolactin and corticosterone were measured. All types of stress in the morning of proestrus induced a reduction in the number of oocytes. Restraint stress (1 h) in the afternoon of proestrus induced a significant reduction in the lordosis quotient. Peripheral and central losartan, but not PD123319, injections partly reverted the effects of stress on ovulation in the morning of proestrus. Acute stress in the morning of proestrus also reduced luteinizing hormone, progesterone and prolactin surges later on the same day. In conclusion, acute stress on the day of proestrus can affect female reproductive physiology. Moreover, the angiotensinergic system, through AT(1) receptors, participates in the effects of acute stress in the morning of proestrus.

Scientia Medica, 2016

Aims: To evaluate the effect of caloric and non-caloric soft drink intake on food consumption, bo... more Aims: To evaluate the effect of caloric and non-caloric soft drink intake on food consumption, body weight and composition, and metabolic parameters in rats. Methods: Controlled experimental study in which 30 male Wistar rats were divided into three groups and given food and beverage ad libitum during 17 weeks. The groups were as follows, according to the offered food: Control group-standard chow and water; Caloric soft drink group-standard chow, caloric soft drink, and water; and Non-caloric soft drink group-standard chow, non-caloric soft drink, and water. Results: There was no statistical difference in total energy intake, body weight, and fat deposition between groups. However, the chow energy intake was 45% lower in the caloric soft drink group compared to the control and non-caloric soft drink groups (198.7±0.7 kJ vs. 349.4±2.0 and 373.0±1.3 kJ, respectively), with 46% of the energy provided by the soft drink. The caloric soft drink group consumed 22% more carbohydrate, especially sucrose, compared to the control group (p<0.05). Macronutrient intake was not different between the control and non-caloric soft drink groups, but the caloric soft drink group consumed less protein and lipids when compared to the other groups (3.5±1.0 g of protein vs. 6.2±0.1 and 6.7±0.1 g, respectively; 0.7±0.01 g of lipids vs. 1.3±0.02 g and 1.4±0.02 g, respectively). Consumption of non-caloric soft drinks increased total sodium intake and consumption of both soft drinks decreased water intake. Although body weight varied during the experiment, there was no significant difference between groups at the end of the experiment, and no difference in fat deposition, fasting glucose, insulin and leptin, insulin resistance index, and lipid profile. Conclusions: The consumption of both types of soft drinks did not affect energy intake, body weight and composition, or metabolic parameters; however, it increased fluid intake and decreased water ingestion. Caloric soft drink intake influenced the amount and the quality of solid food consumed, compromising diet quality.

A estimulação neonatal (EN) em ratos provoca alterações comportamentais e endócrinas estáveis na ... more A estimulação neonatal (EN) em ratos provoca alterações comportamentais e endócrinas estáveis na vida adulta. A regulação da secreção de PRL envolve um complexo sistema, sendo o estrógeno um importante fator estimulatório. A PRL responde aos estímulos estressantes, entre eles o éter. Resultados prévios, em nosso laboratório, demonstraram que a EN afetou a resposta da PRL ao estresse por éter apenas na manhã do diestro II, o que não ocorreu na manhã do estro. O objetivo deste experimento foi mensurar a concentração plasmática de estradiol para avaliar sua interação com a EN na resposta da PRL ao estresse por éter em ratas adultas na manhã do estro e do diestro II. Para isso foram utilizadas 46 ratas Wistar prenhes divididas em dois grupos experimentais: não-estimulado (NE) e estimulado (E). As ninhadas do grupo E sofreram estimulação tátil, diariamente, durante 1 minuto do 1 o ao 10 o dia pós-natal. Já o grupo NE não sofreu nenhum tipo de intervenção. Ao desmame, os filhotes foram separados por sexo. Nas fêmeas adultas, o ciclo estral foi acompanhado e cada um dos grupos foi subdividido em dois subgrupos: manhã do estro e manhã do diestro II. Na manhã do estro ou diestro II as fêmeas foram submetidas ao estresse por éter (1 min) e em seguida realizada a coleta de sangue para dosagem de estradiol por RIA. Para análise estatística foi utilizado o teste Newman-Keuls (p<0,05). Não foi observada diferença nas concentrações plasmáticas 139

Hormones and Behavior, May 31, 2002

Research was undertaken to study the role of central angiotensin in the modulation of male sexual... more Research was undertaken to study the role of central angiotensin in the modulation of male sexual behavior, testing the effect of angiotensin II (Ang II) injections into the medial amygdaloid nucleus (MeA). The sexual behavior of adult male Wistar rats was evaluated, 15 min after bilateral intra-amygdaloid microinjection (0.3 l) of saline and 5 doses of Ang II: 10; 25; 50; 100, and 150 fmol. The effects of the Ang II receptor blockade were also studied. We tested the effect of coinjection of Ang II (50 fmol) with the AT 1 antagonist, losartan (20 pmol) and the AT 2 antagonist, CGP 42112 (1 pmol). Ang II inhibited sexual behavior and this inhibition was prevented by the coinjection of AT 1 antagonist, losartan, or the AT 2 antagonist, CGP 42112. Results show that Ang II has a powerful effect on male sexual behavior, which may be mediated by both AT 1 and AT 2 receptors.

Physiology Behavior, May 31, 2004

Neonatal handling induces behavioral and hormonal changes, characterized by reduced fear in novel... more Neonatal handling induces behavioral and hormonal changes, characterized by reduced fear in novel environments, and lesser elevation and faster return to basal levels of plasma corticosterone, prolactin and adrenaline, in response to stressors in adulthood. The present study aimed to analyze the effects of neonatal handling from Days 1 to 10 postnatal on prolactin response to ether stress in male and female rats at three life periods: neonatal, peripubertal and adulthood. Moreover, adult females were tested in two different phases of the estrous cycle, i.e., diestrus and estrus. In another set of experiments, the behavior of peripubertal and adult males and females in estrus and diestrus was analyzed in the elevated plus maze test. Pups were either handled for 1 min (handled group) or left undisturbed (nonhandled group) during the first 10 days after delivery. In adults, in the handled females in diestrus, stress induced a lesser increase in plasma prolactin compared with nonhandled ones, as in males. However, in estrus, handled females showed no difference in the prolactin response to stress. In the elevated plus maze, handled females in diestrus, but not in estrus, showed higher locomotor activity compared with nonhandled ones. Peripubertal male and female rats handled during the neonatal period showed no difference in behavior in the elevated plus maze compared with nonhandled animals. Early-life stimulation can induce long-lasting behavioral and stress-related hormonal changes, but they are not stable throughout life and phases of the estrous cycle.

A manipulação no período neonatal causa diversas alterações comportamentais e neuroendócrinas na ... more A manipulação no período neonatal causa diversas alterações comportamentais e neuroendócrinas na vida adulta do animal. O objetivo deste trabalho visa descrever os efeitos da manipulação neonatal sobre o número de neurônios do Locus Coeruleus (LC) em fêmeas com 11, 26, 35 e 90 dias de idade. Ratas Wistar divididas em 2 grupos: não-manipuladas (n=6 em cada idade) e manipulados (1 min por dia durante os 10 primeiros dias pós-natal,n=6 em cada idade). Aos 11, 26, 35 e 90 dias, ratas foram perfundidas e cérebros fixados em paraformaldeído 4%. Após inclusão, cortes seriados de toda extensão anteroposterior do LC (15 µm de espessura) foram corados com cresil-violeta. A contagem dos neurônios do LC (lado direito) foi feita em 15 cortes amostrados a partir do 3 0 corte com período de 5. A média (±EPM) do número de neurônios nas fêmeas nãomanipuladas aos 11 dias de idade foi 1445,7±358,

The Journal of neuroscience : the official journal of the Society for Neuroscience, 1997

Brain angiotensin II (Ang II) inhibits pituitary prolactin release by an indirect mechanism requi... more Brain angiotensin II (Ang II) inhibits pituitary prolactin release by an indirect mechanism requiring stimulation of dopamine formation and release. We report that [125I]Sar1-Ang II binding to AT1 receptors and AT1A receptor mRNA expression increase selectively in the dorsomedial arcuate nucleus of 17beta-estradiol-primed ovariectomized rats after treatment with progesterone. In hormone-treated rats, arcuate nucleus AT1A receptor mRNA expression is associated with tyrosine hydroxylase-positive neurons. No AT1A receptor mRNA was detected in tyrosine hydroxylase-positive cells of the arcuate nucleus of intact male rats. Conversely, in the anterior pituitary, where local or circulating Ang II stimulates prolactin release, [125I]Sar1-Ang II binding to AT1 receptors and AT1B receptor mRNA expression are decreased in 17beta-estradiol/progesterone-treated ovariectomized rats. Thus, AT1A receptors in the dorsal arcuate nucleus and AT1B receptors in the anterior pituitary are regulated inver...

Clinical & Biomedical Research

J Endocrinol, 2006

Physiology Behavior, Nov 23, 2007

Scientia Medica, 2016

Hormones and Behavior, May 31, 2002

Physiology Behavior, May 31, 2004

The Journal of neuroscience : the official journal of the Society for Neuroscience, 1997