Evidence for a lack of inositol--(1,4,5)trisphosphate kinase activity in norepinephrine-perfused rat hearts.
The products of the phosphatidylinositol turnover pathway in norepinephrine-perfused hearts have been examined using high performance liquid chromatography. Inositol-1 phosphate, inositol-(1,4)bisphosphate and inositol-(1,4,5)-trisphosphate were all increased in response to norepinephrine stimulation. However, at perfusion times from 5 sec to 20 min there was no appearance of inositol-(1,3,4,5)tetrakisphosphate or inositol-(1,3,4)trisphosphate. This suggests the absence of the inositol-(1,4,5)trisphosphate phosphorylation/dephosphorylation pathway in heart and demonstrates that this secondary pathway is not essential to the functioning of the phosphatidylinositol turnover cycle.
Woodcock
E A
EA
Monash University Department of Medicine, Melbourne, Australia.
Smith
A I
AI
Wallace
C A
CA
White
L B
LB
D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D006321:Heart / Q000187:drug effects; D007295:Inositol Phosphates / Q000302:isolation & purification; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology*; D010477:Perfusion; D010770:Phosphotransferases / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor); D051381:Rats; D011919:Rats, Inbred Strains
D007295:Inositol Phosphates; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C051038:Inositol 1,4,5-trisphosphate 3-kinase; D009638:Norepinephrine