Norepinephrine evokes a marked Mg2+ efflux from liver cells.
The addition of norepinephrine to perfused rat livers and to collagenase isolated hepatocytes induced a marked and dose-dependent magnesium efflux. The addition of beta-adrenergic receptor antagonists, but not alpha-antagonists, completely blocked the Mg2+ efflux. The Mg2+ efflux could also be induced by forskolin and by permeable cAMP analogues. By contrast, the addition of carbachol or vasopressin induced a Mg2+ influx into isolated hepatocytes. These results indicate that a significant Mg2+ efflux from liver cells can be induced through the beta-adrenergic receptors and that it is mediated through the cytosolic cAMP levels.
Romani
A
A
Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, OH 44106.
Scarpa
A
A
D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014667:Vasopressins / Q000494:pharmacology
D014667:Vasopressins; D005576:Colforsin; D002217:Carbachol; D011433:Propranolol; D000242:Cyclic AMP; D008274:Magnesium; D009638:Norepinephrine; D010646:Phentolamine