Effects of glucagon and vasopressin on hepatic Ca2+ release.
The effects of physiological levels of glucagon on Ca2+ efflux were examined in the perfused rat liver. Two methods were used to estimate Ca2+ efflux: prior labeling of the calcium pools with 45Ca2+ and measurement of perfusate Ca2+ with atomic absorption. According to both methods, glucagon administration at the physiological level evoked Ca2+ release. The released Ca2+ originated mostly from a carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP)-depletable pool and also from an FCCP-insensitive pool from which Ca2+ could be released with A23187. Maximally effective doses of glucagon and vasopressin had no additive effect on Ca2+ release. Prior administration of vasopressin resulted in markedly reduced Ca2+ release by glucagon. These results indicate that glucagon releases Ca2+ from the same pool that vasopressin does.
Kraus-Friedmann
N
N
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D004347:Drug Interactions; D005934:Glucagon / Q000494:pharmacology*; D008099:Liver / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism; D051381:Rats; D014667:Vasopressins / Q000494:pharmacology
D014667:Vasopressins; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D005934:Glucagon; D002118:Calcium