THE EFFECTS OF BAY K-8644 ON AGONIST-INDUCED CONTRACTIONS IN GUINEA-PIG URINARY-BLADDER

In this study the effects of Bay K 8644 a new Ca2+ channel activator, on agonist-induced contractions in guinea-pig urinary bladders were investigated. Histamine and serotonin (10(-9) - 10(-4) M) produced a dose-dependent contraction. Maximum contraction was obtained by 10(-5) M serotonin. Its value was 990.00 mg

The Effect of Endothelium on the Response To Propofol on Bovine Coronary-Artery Rings

WOS: A1995TG82700018PubMed ID: 8607314In this study the effect of propofol on isolated bovine coronary artery tone was studied in artery rings precontracted with PGF(2 alpha). Propofol, in concentrations of 10(-6)-10(-5) M did not change vascular smooth muscle tone, but at high concentrations (10(-4)10(-1) M) produced relaxation in rings with intact endothelium. In rings denuded of endothelium or treated with methylene blue, propofol produced relaxation at 10(-3)-10(-1) M concentrations, but there was a significant decrease in relaxation compared to endothelium intact rings. In the presence of a calcium agonist (Bay K 8644; 10(-5) M), propofol produced constriction in rings denuded of endothelium. These results suggest that high concentrations of propofol may hale vasorelaxant effect on bovine coronary artery and that these effects may be due to actions on the endothelium and mediated by calcium channels

The effect of edothelium on the response to propofol on bovine coronary artery rings

PubMed ID: 8607314In this study, the effect of propofol on isolated bovine coronary artery tone was studied in artery rings precontracted with PGF2?. Propofol, in concentrations of 10-6-10-5 M did not change vascular smooth muscle tone, but at high concentrations (10-4-10-1 M) produced relaxation in rings with intact endothelium. In rings denuded of endothelium or treated with methylene blue, propofol produced relaxation at 10-3-10-1 M concentrations, but there was a significant decrease in relaxation compared to endothelium intact rings. In the presence of a calcium agonist (Bay K 8644; 10-5 M), propofol produced constriction in rings denuded of endothelium. These results suggest that high concentrations of propofol may have vasorelaxant effect on bovine coronary artery and that these effects may be due to actions on the endothelium and mediated by calcium channels. Copyright © 1995 Acta Anaesthesiol Scan

Selective and nonselective neuronal NOS inhibitors impair cognitive function in the three panel runway and passive avoidance tasks in rats

The aim of this study was to compare the effects of both neuronal NOS (nNOS) and inducible NOS (iNOS) inhibitor 2-iminobiotin, with the more selective nNOS inhibitor N-omega-propyl-L-arginine (NPLA) and selective inducible NOS (iNOS) inhibitor aminoguanidine, on emotional learning, working memory and reference memory, by using three panel runway and passive avoidance paradigm in order to clarify the role of distinct isoforms of NOS in the regulation of learning and memory functions. NPLA and 2-iminobiotin significantly increased the number of errors and latency of working and reference memory performances of rats in three panel runway paradigm and impairs retention for the passive avoidance task. However, aminoguanidine did not affect cognitive functions in three panel runway and passive avoidance test. The effect of NPLA and 2-iminobiotin was reversed by pretreatment with a NOS substrate L-arginine. In conclusion, NPLA and 2-iminobiotin impaired cognitive functions in different kind of tasks used in this study and the effect of NPLA and 2-iminobiotin was found to be NO-dependent. Our results may confirm that nNOS plays the key role on emotional learning, working memory and reference memory in rats. (C) 2012 Elsevier Inc. All rights reserved.Kocaeli UniversityKocaeli University [2007-2010/39]This study was supported by a grant from Kocaeli University Research Fund (Project number: 2007-2010/39) and partly presented at 23rd ECNP Congress, August 28-September 1, 2010, Amsterdam, The Netherlands

Evidence for the involvement of neuronal nitric oxide synthase and soluble guanylate cyclase on cognitive functions in rats

Aims: The influence of 3-bromo-7-nitroindazole (3-Br 7-NI), a potent and selective neuronal nitric oxide synthase (nNOS) inhibitor, and [1H-[1,2,4]-oxadiazole[4,3a]-quinoxaline-1-one] (ODQ), a highly selective, irreversible inhibitor of soluble guanylate cyclase (sGC), on working and reference memory and emotional learning was investigated in rats. Main methods: The effects were assessed in the three-panel runway and step-down passive avoidance task. respectively. Key findings: 3-Br 7-NI (5, 10, and 20 mg/kg) and ODQ (5, 10, and 20 mg/kg) significantly increased the number of errors and latency of both working and reference memory performance of rats and impaired retention for the passive avoidance task. The effect of 3-Br 7-NI was reversed by L-arginine (250 mg/kg). Significance: Findings of the study supported the hypothesis that nNOS inhibition disrupts reference and working memory processes in terms of an impairment in the strategies used for solving learning tasks, and, according to these results, nNOS-sGC may be required for emotional learning and both reference and working memory. (C) 2011 Elsevier Inc. All rights reserved.Kocaeli UniversityKocaeli University [2007-2010/39]This study was supported by a grant from Kocaeli University Research Fund (Project number: 2007-2010/39) and preliminary findings of the study was presented at the 9th World Congress of Biological Psychiatry, June 28-July 2, 2009, Paris-France