Glucagon-stimulated respiration and intracellular Ca2+.
The effects of extra- and intracellular Ca2+ on glucagon-stimulated respiration were examined in perfused rat liver. Glucagon increased the uptake of O2 to a significantly greater extent in Ca2+-containing perfusate than in Ca2+-free perfusate. If, however, the livers were perfused first with Ca2+-containing perfusate for 60 min in order to load the hormone-sensitive Ca2+ pool(s) and subsequently with Ca2+-free perfusate, glucagon was able to stimulate O2 uptake to the same extent in Ca2+-free, as in Ca2+-containing perfusate. These experiments support previous observations of a connection between Ca2+ and the hormonal stimulation of respiration, but indicate a role for intracellular, rather than extracellular, Ca2+ in the process.
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Kraus-Friedmann
D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D005215:Fasting; D005934:Glucagon / Q000494:pharmacology*; D005943:Gluconeogenesis; D007424:Intracellular Fluid / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains
D005934:Glucagon; D002118:Calcium