Effects of RHC-80267, an inhibitor of diacylglycerol lipase, on excitation of circular smooth muscle of the guinea-pig gastric antrum.
Effects of RHC-80267, an inhibitor of diacylglycerol lipase, on excitation of circular smooth muscle of the guinea-pig gastric antrum.
复制标题
二酰甘油脂肪酶抑制剂 RHC-80267 对豚鼠胃窦圆形平滑肌兴奋的影响。
DOI：
10.1540/jsmr.38.153
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Yoshimichi Yamamoto
中科院分区：
文献类型：
--
作者：
Hikaru Suzuki;Y. Kito;H. Fukuta;Yoshimichi Yamamoto
在从豚鼠胃窦分离的环形平滑肌的小段中，研究了二酰基甘油脂肪酶抑制剂RHC-80267对再生慢电位（自发发生或作为去极化细胞内电流注入的结果）和乙酰胆碱（ACh）作用的影响。由于二酰基甘油是蛋白激酶C（PKC）的已知激活剂，因此预计RHC-80267将间接激活PKC。在环形平滑肌束，自发产生的慢电位记录同时从两个给定的细胞是同步的，这表明这两个细胞是电耦合。RHC-80267（0.3-1 μ M）增加了慢电位产生的频率，而对慢电位或静息膜电位的振幅没有改变。RHC-80267也没有改变给定细胞对中的同步电活动，表明细胞间电耦合没有改变。RHC-80267未显著改变根据注入电流产生的电紧张电位幅度计算的平滑肌细胞输入电阻。由去极化刺激诱发的慢电位产生的不应期约为8 s，RHC-80267将其降低至约5 s，对自发或诱发慢电位的振幅无显著改变。ACh（0.5 μ M）使膜去极化约5 mV，并增加慢电位的振幅和频率。RHC-80267可增强ACh对慢电位频率的作用，但对ACh诱发的去极化和慢电位振幅无明显影响。这些结果支持了PKC通过缩短胃平滑肌细胞兴奋的不应期而参与决定慢电位频率的观点。
In small segments of circular smooth muscle isolated from the guinea-pig gastric antrum, the effects of RHC-80267, an inhibitor of diacylglycerol lipase, were investigated both on regenerative slow potentials (either occurring spontaneously or as the result of a depolarizing intracellular current injection) and on the actions of acetylcholine (ACh). As diacylglycerol is a known activator of protein kinase C (PKC), it would therefore be expected that RHC-80267 would activate PKC indirectly. In circular smooth muscle bundles, spontaneously generating slow potentials recorded simultaneously from two given cells were synchronized, indicating that these two cells were electrically coupled. RHC-80267 (0.3-1 microM) increased the frequency of slow potential generation, with no alteration to the amplitude of either the slow potentials or the resting membrane potential. Synchronous electrical activity in a given pair of cells was also unchanged by RHC-80267, indicating that intercellular electrical coupling was not altered. The input resistance of smooth muscle cells calculated from the amplitude of electrotonic potentials produced by injection of current was not significantly altered by RHC-80267. The refractory period for the generation of slow potentials evoked by depolarizing stimuli was about 8 s, and it was decreased to about 5 s by RHC-80267, with no significant alteration to the amplitude of spontaneous or evoked slow potentials. ACh (0.5 microM) depolarized the membrane by about 5 mV and increased the amplitude and frequency of slow potentials. The actions of ACh on the frequency of slow potentials were enhanced by RHC-80267, with no alteration to the amplitudes of both the ACh-induced depolarization and slow potentials. These results support the idea that PKC is involved in determining the frequency of slow potentials, by shortening the refractory period for excitation of gastric smooth muscle cells.
影响因子：
29.4
作者：
Sanders, KM
通讯作者：
Sanders, KM