Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mitochondria were prepared by a method including a Percoll purification step after the rapid homogenization of livers of fed rats which had been perfused either under unstimulated conditions or in the presence of vasopressin and/or glucagon. The two hormones separately or together increased the total calcium content of the mitochondria. This enhancement was accompanied by parallel increases in activities of the Ca2+-sensitive intramitochondrial enzymes pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase. The effects of the two hormones on total mitochondrial calcium and on the activities of the oxidative enzymes were additive. The persistent enhancements of mitochondrial calcium content and enzyme activities were partially reversed by the addition of Na+ ions to the mitochondrial incubations; these effects of Na+ were blocked by diltiazem, a selective inhibitor of Na+-induced Ca2+ release. Mitochondria from control livers were incubated in vitro with CaCl2 to achieve various calcium content, and mitochondrial enzyme activities and calcium content were measured. A good correlation was obtained between the total calcium content and the activities of pyruvate dehydrogenase and oxoglutarate dehydrogenase. The results obtained are consistent with the hypothesis that vasopressin and glucagon additively cause increases in intramitochondrial [Ca2+] and so bring about the activations of these key enzymes of mitochondrial oxidative metabolism.
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PMID:Vasopressin and/or glucagon rapidly increases mitochondrial calcium and oxidative enzyme activities in the perfused rat liver. 301 64

The hormonal regulation of gluconeogenesis and ureogenesis in isolated rat hepatocytes with 5 mM-proline as precursor was studied, with the following results. (1) The formation of glucose and urea in a 30 min interval were stimulated more by vasopressin than by glucagon, and the effects of the two hormones in combination were additive. (2) The rates of gluconeogenesis during the 30 min were constant under control, glucagon-stimulated and glucagon-plus-vasopressin-stimulated conditions. The stimulated rate in the presence of vasopressin diminished with time; glucagon in combination with vasopressin prevented this diminution, resulting in an additive effect. (3) Coincident with these changes in gluconeogenesis, vasopressin caused a decrease in cell oxoglutarate concentration, which, in contrast with the decrease caused by glucagon, was greater, but not sustained unless glucagon was also present. Changes in cell glutamate concentration similar to those observed for oxoglutarate occurred. (4) The data suggest that activation of oxoglutarate dehydrogenase (EC 1.2.4.2) by glucagon and vasopressin by different mechanisms may explain the relative effects of the hormones alone and in combination on gluconeogenesis from proline.
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PMID:Distinct effects of glucagon and vasopressin on proline metabolism in isolated hepatocytes. The role of oxoglutarate dehydrogenase. 614 93