摘要
应用细胞内微电极技术,观察了辣椒素(capsaicin,CAP)对豚鼠乳头状肌细胞的电生理效应。结果表明:(1)CAP (30、60、120μmol/L)可浓度依赖地缩短正常乳头状肌的动作电位时程。(2)对部分去极化乳头状肌,CAP(60μmol/L)除缩短动作电位时程外,还使动作电位幅值和超射值降低,零相最大上升速度减慢。(3)预先应用L型钙通道开放剂 Bay K8644(0.5μmol/L),则可阻断 CAP(60μmol/L)的电生理效应。(4)预先应用辣椒素受体(va-nilloid receptor,VR)阻断剂钌红(20μmol/L),不影响 CAP(60μmol/L)的电生理效应。以上结果提示,CAP可能通过非受体途径抑制 Ca^(2+)内流,从而影响豚鼠乳头状肌电生理效应。
The cardiac electrophysiological effects of capsaicin (CAP) were examined in guinea pig papillary muscles usingintracellular microelectrode technique. The results obtained are as follows: (1 ) the duration of action potential (APD) in nor-mal papillary muscles was decreased by CAP (30, 60, 120 μmol/L) in a concentration - dependent manner; (2 ) in partiallydepolarized papillary muscles, 60 μmol/L CAP not only reduced APD, but also decreased the amplitude of action potential,overshoot and maximal velocity of phase 0 depolarization; (3 ) pretreatment with L-type Ca^(2+) channel agonist Bay K8644 (0. 5μmol/L) could completely block the effects of CAP (60 μmol/L); (4) pretreatment with ruthenium red (20 μmol/L), avanilloid receptor (VR) blocker, did not affect the actions of capsaicin on papillary muscles. All these results suggest that theeffects of CAP on papillary muscles are likely due to a decrease in calcium influx which is not mediated by VR.
出处
《生理学报》
CAS
CSCD
北大核心
2003年第5期511-515,共5页
Acta Physiologica Sinica
关键词
生理学
辣椒素
动作电位
乳头状肌
physiology
capsaicin
action potential
papillary muscles
