This thesis describes studies to investigate the regulation of guanylate cyclases pathways in blood vessels. Endogenous iS-nitrosothiols have been implicated in the regulation of soluble guanylate cyclase (sGC), by modulating nitric oxide (NO) bioactivity. To determine whether the biotransformation of S-nitrosothiols by isolated rat aorta is enzyme-dependent, stereoisomers of S-nitrosoglutathio...

We have identified imidazopyridine derivatives as a novel class of NO synthase inhibitors with high selectivity for the inducible isoform. 2-[2-(4-Methoxy-pyridin-2-yl)-ethyl]-3H-imidazo[4,5-b]pyridine (BYK191023) showed half-maximal inhibition of crudely purified human inducible (iNOS), neuronal (nNOS), and endothelial (eNOS) NO synthases at 86 nM, 17 microM, and 162 microM, respectively. Inhi...

Effect of genistein, a protein tyrosine kinase inhibitor, on TAME-esterase induced contractions were studied on rat aorta strips in vitro. Data showed that TAME-esterase induced contractions were concentration dependent and these contractions were significantly inhibited when rat aorta strips were pre-incubated with genistein. The present findings provide evidence for the possible contribution ...

The petroleum ether soluble fraction (SIPE) of the root extract of S. indicum was evaluated for the vasorelaxant activity using isolated rat aorta. SIPE up to 180 microg/ml concentration significantly inhibited phenylephrine- and KCl-induced contraction to the extent of 98.13 +/- 6.37 and 70.19 +/- 3.43% respectively in isolated rat aorta in a concentration dependent manner. The vasorelaxant ac...