Gulderen Sahin - Academia.edu (original) (raw)

Papers by Gulderen Sahin

Turkish Journal of Medical Sciences, 1996

Acta Neurobiologiae Experimentalis, 2021

In this study, we investigated the protective effects of angiotensin IV (Ang IV) on cognitive fun... more In this study, we investigated the protective effects of angiotensin IV (Ang IV) on cognitive function in streptozotocin (STZ)-induced diabetic rats. Male Wistar albino rats, were randomly divided into four groups; control (C), diabetes (Dia, 60 mg/kg, STZ, i.p.), Ang IV (5 µg/kg, s.c.) and Dia+Ang IV. The passive avoidance and Morris water maze (MWM) tests were used to evaluate learning and memory performance. Behavioral tests were carried out between 21 and 30 days after the initial Ang IV injection. Hippocampi were dissected and retained for biochemical and Western blot analysis. The Dia group exhibited the poorest behavioral results, while the Dia+Ang IV group performed highest on the MWM task. Superoxide dismutase, glutathione peroxidase, and malondialdehyde levels increased significantly in the Dia group compared to Dia+Ang IV. Brain-derived neurotrophic factor (BDNF) and N-methyl-D-aspartate levels were significantly elevated, while levels of GABAA significantly decreased, in the Dia+Ang IV group compared to the Dia group. These findings suggest that peripheral administration of Ang IV ameliorated spatial memory in diabetic rats by decreasing hippocampal oxidative stress and BDNF levels.

Scandinavian Cardiovascular Journal, 2020

Objectives. Cardiac transplantation is an effective treatment for advanced heart disease and prot... more Objectives. Cardiac transplantation is an effective treatment for advanced heart disease and protection of the donor organ is directly associated with post-transplantation outcomes. Cardioplegic strategies intend to protect the donor heart against ischemic injury during transplantation procedures. In our study, the effects of three different cardioplegia solutions were evaluated in a rat heart donor model in terms of cellular base. Design. Cardioplegia solutions as St. Thomas, del Nido or Custodiol were administered to male Wistar albino rats until cardiac arrest. Arrested hearts were excised and incubated in cold cardioplegia solutions for 4 h. Organ bath experiments were performed using the right ventricular free wall strips of the heart tissues. ATP, sialic acid, TNF-a levels and MMP-9 activities were measured in heart tissues. Incubation media were also used to measure TNF-a and troponin-I levels following organ baths experiments. Results. Custodiol administration led to reduced myocardial contraction (p < .05), decreased ATP levels (p < .001) and increased both TNF-a levels (p < .05), and MMP-9 activity (p < .05). Additionally, troponin-I and TNF-a levels in media were significantly increased (p < .05), TNF-a levels were positively correlated with MMP-9 activities (r ¼ .93, p ¼ .007) and negatively correlated with ATP levels (r ¼ À.91, p ¼ .01) in the Custodiol group. Also, MMP-9 activities were negatively correlated with ATP levels (r ¼ À.90, p ¼ .01) Conclusion. Custodiol cardioplegia cannot prevent functional and cellular damage in donor heart tissue. St. Thomas or del Nido cardioplegia could result in superior functional and biochemical improvement during transplantation procedures. In this respect, these cardioplegic solutions may be more advantageous as cellular and functional.

Cal›ﬂmam›zda Na-pentobarbital (25 mg/kg i.v) ile anesteziye edilen intakt (Periferik kimoreseptor... more Cal›ﬂmam›zda Na-pentobarbital (25 mg/kg i.v) ile anesteziye edilen intakt (Periferik kimoreseptorleri sa¤lam) ve periferik kimoreseptorleri denerve tavﬂanlar kullan›ld›. Her iki grup tavﬂanda sol lateral ventrikul icine adenozin geri-al›m inhibitoru olan dipyridamole (0.05-0.1mg) yan ventrikul icine intraserebroventrikuler (ICV) uygulanarak, endojen adenozinin'in santral solunum kontrol mekanizmalar›na ve hipoksiye karﬂ› oluﬂan solunumsal cevaba etkisi incelendi. ‹ntakt ve kimodenerve grup tavﬂanlara, ICV dipyridamole uygulanmas› oncesinde ve sonras›nda, gerek hava (normoksi) gerek- se hipoksik gaz kar›ﬂ›m› (% 8 O2 - % 92 N2) solutulmas›nda soluk hacmi (VT), solunum frekans› (f/dk.) ve sistemik arteriyel bas›nc (SAB) poligrafta kaydedildi. VT ve f/dk. de¤erlerinden solunum dakika hacmi (VE) hesapland›. . ‹ntakt grup tavﬂanlara hipoksik gaz kar›ﬂ›m› solutulmas› f/dk., VT, VE ve SAB'da anlaml› art›ﬂlar oluﬂturdu (p < 0.01, p < 0.05, p < 0.05, p < 0.001). ICV dipyri...

Journal of Investigative Surgery, 2019

Background: Despite the progress in the treatment of acute kidney injury (AKI), current curative ... more Background: Despite the progress in the treatment of acute kidney injury (AKI), current curative approaches fail to provide adequate treatment. In this study, we aimed to investigate the possible protective effects of thymosin-b-4(Tb4) on an ischemic AKI model in rats. Methods: Rats were randomly assigned into four groups (n ¼ 8/group): The control group (shamoperated), the ischemia-reperfusion (I/R) group; renal ischemia (90 min) by infrarenal abdominal aortic occlusion followed by reperfusion (3 h), the Tb4 þ I/R group; treated with Tb4 before I/R, and the I/Tb4/R group; treated with Tb4 just before reperfusion. Besides renal function determination (creatinine (Cr) and blood urea nitrogen (BUN)); histological evaluation was also conducted. Renal tissue caspase-9, matrix metalloproteinase (MMP-9) activities, and hyaluronan levels were measured. Additionally, renal tissue oxidative stress (lipid hydroperoxide, malondialdehyde, superoxide dismutase, glutathione, pro-oxidant-antioxidant balance, ferric reducing antioxidant power, nitric oxide), inflammation (tumor necrosis factor-a, interleukin-1b, interleukin-6, nuclear factor-jb) were evaluated. Results: I/R increased the level of caspase-9, MMP-9 activity, and hyaluronan (p < 0.001) and these were significantly decreased in both Tb4 groups. Moreover, I/R led to increases in oxidative stress and inflammation parameters (p < 0.001) while the levels of antioxidants were decreased. Nevertheless, Tb4 in both groups were able to restore oxidative stress and inflammation parameters. Furthermore, Tb4 attenuated histologic injury caused by I/R (p < 0.01) and diminished serum urea-creatinine levels (p < 0.001). Conclusion: These results suggest that Tb4 has significant improving effects in ischemic acute kidney injury. This beneficial effect might be a result of the inhibition of extracellular matrix remodeling and apoptosis cascade via modulation in renal redox status and inflammation.

Journal of Applied Physiology, 1993

Both sides of the nasal vasculature of the dog in vivo were perfused separately, with measurement... more Both sides of the nasal vasculature of the dog in vivo were perfused separately, with measurement of vascular resistance responses to stimulation of various nerves. Stimulation of the central end of a cut superior laryngeal nerve caused an ipsilateral vasodilation (-4.98%) and a contralateral vasoconstriction (+3.96%), the difference being statistically significant (P < 0.01). Stimulation of a glossopharyngeal nerve caused vasodilation on both sides, the ipsilateral (-17.52%) being greater than the contralateral (-6.33%) response (P < 0.05). Mechanical stimulation of the nasal mucosa caused little ipsilateral change (+0.47%) and a weak contralateral vasoconstriction (+3.78%; P < 0.01). Stimulation of the central end of a cervical vagus nerve caused vasodilations on both sides, the ipsilateral (-9.75%) being greater than the contralateral (-5.73%) change (P < 0.05). With bilateral perfusions of the cervical tracheal arteries, stimulation of a superior laryngeal nerve caus...

Journal of Applied Physiology, 1987

With anesthetized dogs we have measured upper tracheal vascular resistance on both sides of the t... more With anesthetized dogs we have measured upper tracheal vascular resistance on both sides of the trachea simultaneously by perfusing the cranial tracheal arteries and measuring inflow pressures at constant flows. The ratio of pressure to flow gave vascular resistance (Rtv). Lung airflow, blood pressure (BP), heart rate, and pressure in a cervical tracheal balloon (Ptr) were also measured. In paralyzed dogs, systemic hypoxia due to artificial ventilation with 10% O2–90% N2 increased Rtv by +8.1 +/- 1.0% (SE), Ptr by +76 +/- 22.8%, and BP by +18.9 +/- 24%. After bilateral cervical vagosympathectomy the increases in Rtv and BP were present (+8.8 +/- 0.9 and +22.3 +/- 0.3%, respectively). After carotid body denervation Rtv, Ptr, and BP increased (+6.4 +/- 1.3, +58.6 +/- 31.6, and +14.6 +/- 3.3%, respectively). After vagotomy Rtv and BP increased (+14.1 +/- 1.7 and +22.4 +/- 10.1%, respectively). Tracheal perfusion with hypoxic blood caused a small vasodilation (-2.2 +/- 1.1%). Systemic h...

The Journal of Physiology, 1987

1. With pentobarbitone-anaesthetized dogs, the cranial tracheal arteries have been independently ... more 1. With pentobarbitone-anaesthetized dogs, the cranial tracheal arteries have been independently perfused on both sides, to measure vascular resistance. Blood pressure and contractions of tracheal muscle were also measured. 2. Capsaicin was injected intravenously to stimulate lung C-fibre receptors. In breathing and in paralysed artificially ventilated dogs it decreased tracheal vascular resistance and blood pressure, and contracted tracheal muscle. The effects were abolished or far smaller after bilateral cervical vagosympathectomy. 3. Veratrine was injected intravenously to stimulate slowly adapting pulmonary stretch receptors and cardiac receptors. In breathing and in artificially ventilated dogs it lowered tracheal vascular resistance and blood pressure, and had variable effects on tracheal muscle tone. The vascular effects were prevented by vagotomy. 4. Veratrine injected into the left atrium caused similar vascular changes to intravenous administration. The changes were prevented by vagotomy. Veratrine causes a tracheal vasodilatation by action on cardiac receptors. 5. Inflation of the lungs in artificially ventilated dogs, to stimulate slowly adapting pulmonary stretch receptors, had no effect on tracheal vascular resistance but decreased blood pressure and tracheal muscle tone, the latter being prevented by vagotomy. 6. Bilateral carotoid arterial occlusion, to decrease the discharge in carotid sinus baroreceptors, had no effect on tracheal vascular resistance but increased blood pressure and contracted tracheal muscle, the last two responses being greatly reduced by cutting the sinus nerves. 7. It is concluded that stimulation of lung C-fibre and cardiac receptors causes a reflex tracheal vasodilatation, but that no changes in the tracheal vascular bed occur with stimulation of slowly adapting pulmonary stretch receptors or inhibition of carotid sinus baroreceptors.

Canadian journal of physiology and pharmacology, Jan 15, 2017

Aortic cross-clamping induced ischemia reperfusion (IR) is an important factor in development of ... more Aortic cross-clamping induced ischemia reperfusion (IR) is an important factor in development of postoperative acute cardiac injury following abdominal aortic surgery. We investigated the possible antioxidant/anti-inflammatory effects of fluoxetine (FLX), which used widely as a preoperative anxiolytic, on cardiac injury induced by IR of infrarenal abdominal aorta. FLX was administered to IR (60-min ischemia and 120-min reperfusion) performed rats for 3 days, once daily at 20 mg/kg, i.p. dosage. Results were compared to control and non-FLX treated IR performed rats. Serum creatine kinase (CK) and creatine kinase-MB (CK-MB) levels, lipid hydroperoxide, malondialdehyde, and pro-oxidant/antioxidant balance levels in IR group were significantly higher whereas superoxide dismutase activity, glutathione and ferric reducing/antioxidant power levels were lower than control. IR also increased myeloperoxidase activity, tumor necrosis factor-α, interleukin-1β, interleukin-6 and decreased IL-10 ...

Cerrahpasa Tıp Dergisi, 1998

Calismamizin amaci KOAH ve hiperkarbili hastalarda dusuk karbonhidrat yuksek yag icerikl... more Calismamizin amaci KOAH ve hiperkarbili hastalarda dusuk karbonhidrat yuksek yag icerikli beslenmenin etkilerini degerlendirmektir. 1. ve 15. gunlerde solunum fonksiyonlari yapilarak stabil KOAH olarak degerlendirilen 14 hasta calismaya alindi. Sternocleidomastoid ve external obliq kaslarin elektromiyogramlari ile solunum kaslarinin aktivitesi degerlendirildi. Calisma suresince inhaler steroid, inhaler ve oral beta 2 agonist ve oral teofilin alan hastalarin beslenmesi %16.7 protein, %55.2 yag, %28.1 karbonhidrat, vitaminler ve mineraller iceren 500 ml/gun sivi diyetle (Pulmocare) desteklendi. Diyetten 10 gun sonra FVC anlamli olarak artarken (p<0.05) PaCO2 azaldi (p<0.05). Her iki kasin aktivasyon surelerinde istatistiksel olarak anlamli azalma kaydedildi (p<0.05). Bu veriler dusuk karbonhidrat yuksek yagli diyetin solunum kas fonksiyonlarini iyilestirdigi ve CO2 retansiyonunu azalttigini gostermektedir.

Biochemical Society Transactions, 1993

Indian journal of physiology and pharmacology, 1998

The experiments were conducted in dogs anesthetized with Na-pentobarbital i.v. tidal volume (VT) ... more The experiments were conducted in dogs anesthetized with Na-pentobarbital i.v. tidal volume (VT) and respiratory frequency (f min-1) were recorded. The central effects of acetylcholine (Ach) and epinephrine on respiration were investigated after injections of these substances directly into the cerebrospinal fluid by atlanto-occipital punction. The peripheral effects of Ach and epinephrine on respiration were studied after i.v. injections. Both central and peripheral administration of epinephrine caused significant increase in f min-1 and VT. After vagotomy the effects of centrally and peripherally administered epinephrine on f min-1 were abolished. The effect of central injection of epinephrine on VT persisted after vagotomy. The increase in VT in response to peripheral epinephrine administration was abolished by vagotomy. Both central and peripheral injection of Ach increased f min-1. In VT an initial decrease was followed by an increase. The initial decrease in VT was abolished by...

The Chinese journal of physiology, Jan 30, 2008

Hypoxia causes changes in the rate of synthesis or release of neurotransmitters in the brain. The... more Hypoxia causes changes in the rate of synthesis or release of neurotransmitters in the brain. The accumulation of serotonin (5-HT) in the central nervous system might cause hypoxic respiratory depression. In the present study, we aimed to examine the role of central 5-HT on normoxic and acute hypoxic ventilatory depression (AHVD) in peripheral chemoreceptors denervated rabbits. All experiments were performed in peripherally chemodenervated rabbits anesthetized with intravenous injection of urethane (400 mg/kg) and alpha-chloralose (40 mg/kg). For intracerebroventricular (ICV) administration of 5-HT (20 microg/kg) and ketanserin (10 microg/kg), a cannula was placed in left lateral ventricle by stereotaxic method. Respiratory frequency (fR), tidal volume (VT), ventilation minute volume (VE) and systemic arterial bood pressure (BP) were recorded in each experimental phases and mean arterial pressure was calculated (MAP). Heart rate (HR) was also determined from the pulsation of BP. The...

Journal of Basic and Clinical Physiology and Pharmacology, 1999

The branch of the cranial superior thyroid artery that supplies the larynx was perfused unilatera... more The branch of the cranial superior thyroid artery that supplies the larynx was perfused unilaterally at a constant flow rate in dogs anesthetized with pentobarbitone sodium (30 mg.kg-1, i.v.). Laryngeal vascular resistance (RLv) was calculated. Intraluminal laryngeal pressure (PL) was determined. Asphyxia caused a diminution in PL (-27.7 +/- 4.2%) (p < 0.01) and an initial decrease followed by an increase in RLv (-10.9 +/- 2.3% and +12.8 + 2.8%) (p < 0.001). Following vagotomy, asphyxia decreased PL (-17.1 +/- 4.2%) and increased RLv (+45.5 +/- 11.0%). Systemic hypoxia induced by breathing 8% O2-N2 increased RLv (+8.4 +/- 1.3%) (p < 0.001) and decreased PL (-24.9 +/- 3.7%) (p < 0.001). In chemodenervated dogs, the response of PL to hypoxia was abolished while that of RLv was similar to that in intact animals. Breathing of 7% CO2 in air caused an increase in RLv (+6.1 +/- 1.6%) (p < 0.001) and a decrease in PL (-20.9 +/- 3.2%) (p < 0.001). Following chemodenervation, hypercapnia still increased RLv (+11.3 +/- 3.2%) (p < 0.01) and diminished PL (-29.9 +/- 2.5%). Bilateral vagotomy reduced the response of PL to hypercapnia (-13.3 +/- 6.9%) (p < 0.05). Local intra-arterial injection of KCN produced an increase in RLv and PL (+7.0 +/- 1.2%, +9.0 +/- 1.0%). After peripheral chemodenervation KCN injection slightly increased PL (+2.0 +/- 0.9%). The response of RLv was almost abolished. In conclusion, laryngeal vasoconstriction in response to systemic hypoxia after chemodenervation is probably mediated by increased sympathetic discharge to the larynx due to hypoxia of the CNS. Laryngeal responses to hypercapnia may be due to the action of central chemoreceptors.

The Tohoku Journal of Experimental Medicine, 2002

The Tohoku Journal of Experimental Medicine, 1997

The Tohoku Journal of Experimental Medicine, 2004

In anaesthetized dogs (sodium pentobarbitone 30 mg/kg, i.v.) laryngeal vascular resistance was me... more In anaesthetized dogs (sodium pentobarbitone 30 mg/kg, i.v.) laryngeal vascular resistance was measured by unilateral perfusion at constant flow of the branch of the cranial superior thyroid artery that supplies the larynx. Arterial perfusion was at constant flow and inflow pressure was divided by flow to give laryngeal vascular resistance (R LV). Intraluminal laryngeal pressure (P L) and systemic arterial blood pressure (BP) were also measured. Stimulation (20 V, 20 Hz, 0.2 milliseconds) of the central end of cervical vagus caused an increase in R LV (+22.9±6.1%) and a decrease in P L (−12.1±4.4%). Stimulation (10 V, 10 Hz, 0.2 milliseconds) of the central end of the recurrent laryngeal nerve (RLN) reduced R LV (−3.4±0.8%) and P L (−7.5±4.1%). Stimulation of the peripheral end of the RLN decreased R LV (−7.1±1.9%) and increased P L (+21.6±7.7%). Stimulation of the central end of the superior laryngeal nerve (SLN) increased R LV (+17.9±3.2%) and P L (+59.8±2.7%), whereas stimulation of the peripheral end of the SLN decreased R LV (-4.8±1.6%) and P L (−4.1±2.4%). After treatment with α-adrenoreceptor antagonist phentolamine (0.5 mg/kg, i.v.), stimulation of the central end of cervical vagus nerve reduced R LV by 25% and decreased BP. Phentolamine caused a decrease in BP and reduced the magnitude of increase in R LV in response to stimulation of central end of SLN. After atropine sulphate (0.5-2.0 mg/kg, i.v.), the stimulation of both central and peripheral ends of RLN reduced R LV. The decrease in R LV during stimulation of peripheral end of SLN was reduced by atropine. Thereafter, pancuronium bromide (0.06-0.1 mg/kg, i.v.) was given and dogs were artifically ventilated. After paralyzed, stimulation of the central end of the SLN decreased R LV (+26.0±4.5%) but produced no change in P L. It is concluded that parasympathetic motor fibers in the RLN and SLN are effective for the laryngeal vascularity and non-adrenergic system may be responsible for laryngeal vasoconstriction. laryngeal vasculature; vagal stimulation; phentolamine; atropine