腺苷对大鼠膀胱收缩性和45钙摄取的影响。

Effects of adenosine on contractility and 45Ca-uptake in rat urinary bladder.

作者信息

Parija S C, Raviprakash V, Mishra S K

机构信息

Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar.

出版信息

Indian J Exp Biol. 1994 Nov;32(11):781-5.

PMID:7896306

Abstract

Effects of adenosine on K+ and ACh-stimulated contractility and 45Ca uptake were studied in the rat urinary bladder smooth muscle and were compared with those of nifedipine. Both adenosine (10(-5) M) and nifedipine (10(-7) M/10(-8) M) significantly inhibited the contractions elicited by K+ (10(-2)-32 x 10(-2) M), Ca2+ (10(-4)-3 x 10(-2 M) in K(+)-depolarized preparations and ACh (10(-9) M-3 x 10(-3) M). Further, adenosine (10(-5) M) significantly (P < 0.05) inhibited K+ (10(-1) M)-stimulated 45Ca-uptake in the bladder strips. However, it had little effect on inward 45Ca movement resulting from ACh (10(-4) M)-induced stimulation. On the other hand, nifedipine (10(-7) M) significantly (P < 0.001) reduced both K+ and ACh-induced 45Ca-uptake in this tissue. It is concluded that the calcium channel blocking action of adenosine is limited to Ca2+ uptake through voltage operated calcium channels, while receptor operated calcium channels activated by muscarinic receptor stimulation appear to be insensitive to the purine.

摘要

研究了腺苷对大鼠膀胱平滑肌中钾离子（K⁺）和乙酰胆碱（ACh）刺激的收缩性以及⁴⁵Ca摄取的影响，并与硝苯地平的作用进行了比较。腺苷（10⁻⁵M）和硝苯地平（10⁻⁷M/10⁻⁸M）均显著抑制了由K⁺（10⁻² - 32×10⁻²M）、在K⁺去极化制剂中的Ca²⁺（10⁻⁴ - 3×10⁻²M）以及ACh（10⁻⁹M - 3×10⁻³M）所引发的收缩。此外，腺苷（10⁻⁵M）显著（P < 0.05）抑制了膀胱条带中K⁺（10⁻¹M）刺激的⁴⁵Ca摄取。然而，它对ACh（10⁻⁴M）诱导刺激所导致的内向⁴⁵Ca移动影响很小。另一方面，硝苯地平（10⁻⁷M）显著（P < 0.001）降低了该组织中K⁺和ACh诱导的⁴⁵Ca摄取。得出的结论是，腺苷的钙通道阻断作用仅限于通过电压依赖性钙通道的Ca²⁺摄取，而由毒蕈碱受体刺激激活的受体依赖性钙通道似乎对嘌呤不敏感。