The effects of adrenalectomy on the alpha-adrenergic regulation of cytosolic free calcium in hepatocytes.

摘要: Abstract We have previously published that bilateral adrenalectomy in the rat reduces Ca2+-mediated alpha-adrenergic activation of hepatic glycogenolysis, while it increases cellular calcium content hepatocytes. In experiments presented here, concentration cytosolic free (Ca2+i) at rest and response to epinephrine was measured aequorin-loaded hepatocytes isolated from sham adrenalectomized male rats. found rats resting Ca2+i elevated, rise evoked by reduced, 45Ca efflux follows such stimulation depressed. Furthermore, slope relationship between decreased 60% adrenalectomized. Adrenalectomy did not change Ca2+ release intracellular pools IP3 saponin-permeabilized The EC50 for inositol 1,4,5-triphosphate maximal released were similar both animals. Finally, liver calmodulin determined radioimmunoassay significantly different These results suggest 1) hepatocyte, probably an effect on plasma membrane (Ca2+-Mg2+)-ATPase-dependent pump thus alters homeostasis; 2) decreases epinephrine; 3) this is due defects storage mobilization processes; 4) effects metabolism glycogenolysis are caused a reduction soluble calmodulin.