Regulation of Mg2+ uptake in isolated rat myocytes and hepatocytes by protein kinase C.
A large Mg2+ cell uptake against concentration gradients is stimulated in collagenase-dispersed rat myocytes by carbachol and in hepatocytes by carbachol or vasopressin. The signalling pathway(s) responsible for this stimulation of Mg2+ uptake was investigated by using various activators or inhibitors of protein kinase C (PKC) and by correlating Mg2+ uptake with cell PKC activity and cAMP content. In both cell preparations, the direct stimulation of PKC by diacylglycerol analogs or phorbol esters reproduce the same pattern of Mg2+ uptake as that induced by carbachol or vasopressin. These data indicate that the activation of PKC is responsible for a stimulation of Mg2+ uptake by myocytes or hepatocytes, whereas increase in cAMP in these cells stimulates Mg2+ release.
Romani
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Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, OH 44106.
Marfella
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C
Scarpa
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D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002458:Cell Fractionation; D000242:Cyclic AMP / Q000378:metabolism; D004075:Diglycerides / Q000494:pharmacology; D008099:Liver / Q000166:cytology / Q000187:drug effects; D008274:Magnesium / Q000378:metabolism*; D008297:Male; D009132:Muscles / Q000166:cytology / Q000187:drug effects; D010703:Phorbol Esters / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D014667:Vasopressins / Q000494:pharmacology
D004075:Diglycerides; D010703:Phorbol Esters; D014667:Vasopressins; D002217:Carbachol; D000242:Cyclic AMP; D011493:Protein Kinase C; D008274:Magnesium