title: Calcitonin increases alanine aminotransferase activity related to calcium in the hepatic mitochondria of rats.
abstract: The effect of calcitonin (CT) on alanine aminotransferase activity and calcium content in the hepatic mitochondria of intact rats was investigated. A single subcutaneous administration of CT (synthetic [Asu1,7] eel calcitonin; 80 MRC mU/100 g body weight) produced a significant increase in alanine aminotransferase activity and a corresponding elevation of calcium content. Those increases were also observed with the lowest dose of CT (20 MRC mU/100 g). The mitochondrial calcium depletion by 10 mM EGTA treatment produced a remarkable reduction in alanine aminotransferase activity increased by CT, although EGTA treatment did not alter basal enzyme activity. Addition of calcium ion (1-10(3) microM) into the EGTA-treated mitochondria, however, produced a significant increase in alanine aminotransferase activity. The enzyme activity increased by CT was not inhibited by the presence of calmodulin inhibitor, W-7 (1-10(3) microM). These results suggest that the mitochondrial calcium increased by CT administration directly activates alanine aminotransferase in the hepatic mitochondria of rats.
mesh_terms: D000410:Alanine Transaminase / Q000378:metabolism*; D000818:Animals; D002116:Calcitonin / Q000494:pharmacology*; D002118:Calcium / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000494:pharmacology; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010710:Phosphates / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D010710:Phosphates; D004533:Egtazic Acid; D002116:Calcitonin; D000410:Alanine Transaminase; D002118:Calcium