Redistribution of subcellular calcium in rat liver on administration of vanadate.
Mitochondria isolated from the livers of rats administered with sodium meta-, ortho-, or polyvanadate, but not vanadyl sulphate, exhibited enhanced Ca2+ -stimulated respiration and uptake of calcium. These effects were shown also by mitochondria isolated from livers perfused with polyvanadate. The concentration of acid-soluble calcium decreased significantly in the mitochondrial fraction on vanadate treatment, while that in the cytosol showed a corresponding increase. Phenoxybenzamine, an antagonist to alpha-adrenergic receptors, effectively inhibited vanadate-induced Ca2+ mobilization, but surgical sympathectomy was without effect. This is the first demonstration of vanadate mimicking alpha-adrenergic agonists in vivo.
Gullapalli
S
S
Department of Biochemistry, Indian Institute of Science, Bangalore.
Shivaswamy
V
V
Ramasarma
T
T
Kurup
C K
CK
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D010477:Perfusion; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012119:Respiration; D013347:Subcellular Fractions / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D014638:Vanadates / Q000494:pharmacology*
D000317:Adrenergic alpha-Antagonists; D011768:Pyruvate Dehydrogenase Complex; D014638:Vanadates; D002118:Calcium