钐对豚鼠结肠带对乙酰胆碱、钾、组胺和钡的收缩反应的影响。

The effects of samarium on the contractile responses of the guinea-pig taenia coli to acetylcholine, potassium, histamine and barium.

作者信息

Turrin M A, De Moraes S

出版信息

Arch Int Pharmacodyn Ther. 1977 Dec;230(2):199-209.

Abstract

The role of calcium in supporting the phasic contractions of the isolated guinea-pig taenia coli induced by acetylcholine, potassium, histamine or barium has been studied using the lanthanid samarium (Sm3+). A carefully selected concentration of Sm3+ (6 X 10(-5)M) depressed to a same extent the phasic responses of the tissue to submaximal concentrations of the agonists used whilst maximum responses to histamine and barium were unaffected. Calcium and barium-induced responses of the depolarized taenia coli were not inhibited by 6 X 10(-5)M Sm3+. The rate of loss of responsiveness of the depolarized tissue to acetylcholine was increased, that to histamine was not altered while that to barium was decreased by 6 X 10(-5)M Sm3+. These findings support the concept that phasic responses of the guinea-pig taenia coli to submaximal concentrations of the agonists used are dependent on a Sm3+-sensitive calcium store(s) probably located at the cell membrane. However, maximum responses to histamine and barium seem to be supported, at least partially, by a Sm3+-insensitive depot(s) probably located at cytoplasmic compartments.

摘要

利用镧系元素钐（Sm3+）研究了钙在支持由乙酰胆碱、钾、组胺或钡诱导的离体豚鼠结肠带相性收缩中的作用。精心选择的Sm3+浓度（6×10−5M）同等程度地抑制了组织对所用激动剂亚最大浓度的相性反应，而对组胺和钡的最大反应不受影响。6×10−5M Sm3+不抑制去极化结肠带对钙和钡的诱导反应。6×10−5M Sm3+增加了去极化组织对乙酰胆碱反应性丧失的速率，对组胺的反应性未改变，而对钡的反应性降低。这些发现支持了这样一种概念，即豚鼠结肠带对所用激动剂亚最大浓度的相性反应依赖于可能位于细胞膜的对Sm3+敏感的钙储存库。然而，对组胺和钡的最大反应似乎至少部分地由可能位于细胞质区室的对Sm3+不敏感的储存库支持。