[Effects of 2-[p-(dimethylamino)styryl]pyridine methiodide on contractive response of rabbit aortic strips].
The effects of 2-[p-(dimethylamino) styryl]pyridine methiodide (DSPM) on rabbit aortic contraction induced by high K+, norepinephrine (NE) and Ca2+ were studied. On rabbit thoracic aortic strips, DSPM inhibited the contraction induced by KCl and NE in normal modified Tyrode's solution. DSPM shifted the dose-response relationships of KCl and NE to the right, and depressed their maximal responses; the pD'2 values were 5.09 and 5.16 respectively. After the strip had been exposed to Ca2(+)-free Tyrode's solution for 2 h, the NE-induced responses were further inhibited by DSPM, whereas the KCl-induced responses were not significantly affected. On depolarized vessels, the dose-response relationships of CaCl2 were also shifted to the right and their maximal responses were also depressed by DSPM, suggesting that DSPM is a non-competitive antagonist. The pD'2 value was 6.86. These results suggest that DSPM is a calcium antagonist. It not only inhibited the influx of extracellular calcium, but also has an inhibitory effect on the release of sequestered calcium in the rabbit aortic smooth muscle.
Wang
X W
XW
Department of Pharmacology, Xinjiang Medical College, Urümqi, China.
Zhou
C M
CM
Zhang
K J
KJ
D000818:Animals; D001011:Aorta / Q000187:drug effects; D002122:Calcium Chloride / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D011726:Pyridinium Compounds / Q000494:pharmacology*; D011817:Rabbits
D011726:Pyridinium Compounds; C011786:2-(4-(dimethylamino)styryl)-1-methylpyridinium; D011189:Potassium Chloride; D002122:Calcium Chloride; D009638:Norepinephrine