J C Stoclet

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Experiments were designed to study the interaction between prejunctional alpha 2-adrenoceptors and both adenosine and opioid receptors at the postganglionic sympathetic nerve endings innervating the tail artery of the rat. Segments of this vessel were preincubated with [3H]-noradrenaline and then perfused/superfused with [3H]-noradrenaline-free medium.(More)
Pertussis toxin (PTX) was used to investigate the possible involvement of a G protein in the mechanism of action of neuropeptide Y (NPY) on rat mesenteric arterioles. ADP ribosylation of membrane protein was assessed by gel electrophoresis followed by autoradiography. The effect of NPY was studied on contractions elicited either by addition of calcium to(More)
We describe a new method to obtain rat aortic endothelial cells without contamination by vascular smooth muscle cells. The endothelial cells were characterized up to the 20th passage by low density lipoprotein incorporation, the absence of alpha-smooth muscle actin, the production of endothelium derived relaxing factor, and an elevation in intracellular(More)
Experiments were designed to investigate the respective roles of adenylate cyclase and cyclic nucleotide phosphodiesterase in the alterations with age of cyclic AMP metabolism-dependent relaxation in rat aorta. Neither basal nor stimulated aortic adenylate cyclase activities from 7- and 18-week-old rats differed significantly. The maximal cyclic AMP(More)
Stimulation of neuropeptide Y (NPY) Y2 receptors induced an intracellular free Ca2+ ([Ca2+]i) increase in a human neuroblastoma cell line, CHP-234. When NPY in a Ca(2+)-free solution was applied, this increase was abolished. Depolarization with high KCl evoked no response, suggesting that the responses were not mediated by voltage-gated Ca2+ channels. There(More)
The effect of endothelin-1 (ET-1) on the increase in perfusion pressure and the release of noradrenaline produced by electrical field stimulation were examined in isolated perfused/superfused rat tail arteries. ET-1 (1-30 nM) increased, in an identical concentration-dependent manner, the basal perfusion pressure and the stimulation-evoked tritum overflow,(More)
The affinities of calcium blocking agents (CBAs) for membrane binding sites and for calmodulin were compared to their potencies at inhibiting contraction of various isolated arteries. Two allosterically linked binding sites, the dihydropyridine (DHPS) and benzothiazepine-phenylakylamine (BS) one, were characterized. In spite of a correlation between the(More)
The interaction of calmodulin antagonists and hydrophobic calcium antagonists with calmodulin and calcium antagonist ( [3H]nitrendipine and [3H]diltiazem) binding sites was investigated. The classical calmodulin antagonists calmidazolium, trifluorperazine, and W-7 were active at similar concentrations in the three experimental systems. The hydrophobic(More)