[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.
Department of Pharmacology, Xinjiang Medical College, Urümqi, China.
X W
XW
Wang
C M
CM
Zhou
K J
KJ
Zhang
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