Regulation of one type of Ca2+ current in smooth muscle cells by diacylglycerol and acetylcholine
Department of Physiology
Acetylcholine; Animals; Bufo marinus; Calcium; Diglycerides; Electrophysiology; Glycerides; Ion Channels; Muscle, Smooth; Protein Kinase C
Life Sciences | Medicine and Health Sciences
Electrophysiological recordings from freshly dissociated smooth muscle cells from the stomach of the toad Bufo marinus revealed two types of Ca2+ currents. One has a low threshold of activation and inactivates rapidly; the other has a high threshold of activation and inactivates more slowly. Acetylcholine (ACh) increased the high-threshold current but not the low-threshold current. The synthetic diacylglycerol analog sn-1,2-dioctanoylglycerol, an activator of protein kinase C (PKC), mimicked these effects of ACh on Ca2+ currents. However, another diacylglycerol analog, 1,2-dioctanoyl-3-thioglycerol, which has a closely related structure but does not activate PKC, failed to increase the Ca2+ current. The same was true of 1,2-dioctanoyl-3-chloropropanediol, an analog that even at high concentrations only minimally activates PKC. These results suggest that diacylglycerol may be the second messenger mediating the effects of ACh on one type of voltage-activated Ca2+ channel, possibly by activating PKC.
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Citation: FASEB J. 1988 Jun;2(9):2497-504.
The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Vivaudou, Michel B.; Clapp, Lucie H.; Walsh, John V. Jr.; and Singer, Joshua J., "Regulation of one type of Ca2+ current in smooth muscle cells by diacylglycerol and acetylcholine" (1988). Open Access Articles. 569.