Possible Interaction: Isoproterenol and Phosphatidic Acid

“However, longer exposure (2 minutes or more) to isoproterenol was associated with increases in the degree of P labeling of phosphatidylinositols and phosphatidic acid.”

“Analysis of 32P incorporation into individual phospholipids and polyphosphoinositides revealed that isoprenaline stimulation of the hearts was associated with a 2-3-fold increase in the degree of phosphorylation of phosphatidylinositol monophosphate and bisphosphate as well as phosphatidic acid in both cardiac homogenates and sarcoplasmic reticulum membranes.”

“Lipolytic agents such as corticotropin, dibutyryl cyclic AMP, adrenaline in the presence of phentolamine and isoproterenol decreased [(32)P]P(i) incorporation into phosphatidylinositol, phosphatidylethanolamine and phosphatidic acid.”

“ Isoproterenol stimulated the labelling of phosphatidic acid but had no effect on phosphatidyl-inositol metabolism in the first 60 min of the incubation.”

“These results indicate that the main effect of isoproterenol on phospholipid metabolism in rat heart is to increase the turnover of phosphatidic acid and to slow down the conversion of phosphatidic acid into phosphatidylinositol.”

“Under our experimental conditions, several adrenergic drugs, including DL-propranolol, phentolamine, isoproterenol , phenylephrine, but not sotalol, increased markedly (nearly up to 5-fold) the 32Pi incorporation into PhA and PhI of the iris.”