KCl and phenylephrine stimulation induced identical conducted electrical responses in smooth muscle and endothelium, suggesting these cells are electrically coupled homocellularly and heterocellularly.
We have previously shown that conducted vasomotor responses follow patterns that are consistent with a passive spread of electrical current along the length of the arterioles (Xia and Duling, Am. J. Physiol. 269 (Heart Circ. Physiol. 38): H2022-H2030, 1995. In this study, we define the cells through which the current flows. Isolated arterioles of hamster cheek pouch were used. The mean resting membrane potential (RMP) for randomly sampled arteriolar cells was -67 mV. When cell types were identified by dye injection, the RMPs were -68 and -67 mV for smooth muscle (SM) and endothelium (EC), respectively. Pulses of KCl induced transient, monophasic depolarizations at the site of stimulation (local), which were conducted decrementally along the length of the arteriole over several millimeters. During electrical conduction, three patterns of responses could be observed, but identical patterns of the conducted electrical responses were always observed in SM and EC. Phenylephrine stimulation also caused transient local and conducted depolarizations in both SM and EC. As with KCl stimuli, shapes of conducted electrical responses were identical in records made in both cell types. The results suggest that SM and EC are electrically coupled both homocellularly and heterocellularly.
Xia et al. (Fri,) reported a other. KCl and Phenylephrine stimulation was evaluated on Resting membrane potential and conducted electrical responses. KCl and phenylephrine stimulation induced identical conducted electrical responses in smooth muscle and endothelium, suggesting these cells are electrically coupled homocellularly and heterocellularly.