Isolation of adult cardiomyocytes initiates a return of inositol trisphosphate phosphorylating activity.
1. We have previously reported that the addition of noradrenaline to [3H]-inositol-labelled adult rat atria or isolated perfused hearts caused the release of inositol-1,4,5-trisphosphate, which was metabolized by dephosphorylation to inositol-4-monophosphate. Inositol-1,3,4,5-tetrakisphosphate and its dephosphorylation products were not detected. 2. In the current study, the addition of noradrenaline to [3H]-inositol-labelled adult rat cardiomyocytes caused the release of inositol-1,4,5-trisphosphate, which was metabolized in part by phosphorylation to inositol-1,3,4,5-tetrakisphosphate. 3. These results demonstrate that the isolation and culture of rat adult cardiomyocytes initiates enhanced generation of inositol-1,3,4,5-tetrakisphosphate. This change would be expected to enhance the calcium response of the cells to stimulation of alpha 1-adrenoceptors.
Woodcock
E A
EA
Baker Medical Research Institute, Prahan, Victoria, Australia.
Anderson
K
K
D000818:Animals; D002478:Cells, Cultured; D002712:Chlorides / Q000494:pharmacology; D007294:Inositol / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D007295:Inositol Phosphates / Q000378:metabolism; D008094:Lithium / Q000494:pharmacology; D018021:Lithium Chloride; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology; D010766:Phosphorylation; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D013268:Stimulation, Chemical; D014316:Tritium
D002712:Chlorides; D007295:Inositol Phosphates; D014316:Tritium; C081655:inositol-1,3,4,5-tetrakisphosphate; D007294:Inositol; D015544:Inositol 1,4,5-Trisphosphate; D008094:Lithium; D011433:Propranolol; D018021:Lithium Chloride; D009638:Norepinephrine