Regulation of Mg2+ homeostasis by insulin in perfused rat livers and isolated hepatocytes.
Several recent studies demonstrate that adrenergic receptor stimulation evokes marked changes in Mg2+ homeostasis. As insulin counter-regulates many of the metabolic consequences of adrenergic receptor stimulation, we evaluated the potential influence of insulin on Mg2+ movements in response to adrenergic stimulation. The data demonstrate that insulin is able to block the Mg2+ efflux from perfused rat livers stimulated by isoproterenol or 8-Br-cAMP, but has little or no effect on epinephrine or phenylephrine induced Mg2+ efflux. Thus, evidence is provided demonstrating that there are redundant adrenergic pathways regulating Mg2+ efflux from liver tissue. One of these pathways, the beta-adrenergic component, is selectively blocked by insulin. Furthermore, these findings may provide a cellular explanation for hypomagnesemia associated with diabetes.
Department of Physiology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106-4907, USA.
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Keenan
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Romani
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Scarpa
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D002478:Cells, Cultured; D004837:Epinephrine / Q000494:pharmacology; D006706:Homeostasis / Q000187:drug effects; D007328:Insulin / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism*; D008297:Male; D008954:Models, Biological; D010477:Perfusion; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011943:Receptors, Adrenergic, beta / Q000502:physiology
D007328:Insulin; D011943:Receptors, Adrenergic, beta; D010656:Phenylephrine; D015124:8-Bromo Cyclic Adenosine Monophosphate; D008274:Magnesium; D007545:Isoproterenol; D004837:Epinephrine