In vitro inhibition by metabolic antagonists of incorporation of [ 32P]phosphate into the major phospholipids of swine coronary and pulmonary arteries

Abstract

Summary Incorporation of [ 32 P]phosphate into sphingomyelin, phosphatidyl choline, phosphatidyl serine and phosphatidyl ethanolamine of normal swine arteries was studied in vitro . Choline added to the media increased the specific activity in phosphatidyl choline, whereas ethanolamine had no significant effects. Addition of 2-amino-2-methyl-l-propanol in concentrations from 0.001–0.1 M inhibited incorporation of 32 P into all the phospholipid classes; phosphatidyl choline was affected to a somewhat greater extent than the others. Ratios of choline to aminomethylpropanol in the media of 1:1 and 10:1 resulted in partial reversal of the inhibition; the reversal was nearly complete at a ratio of 100:1. The pulmonary artery seemed to be somewhat less sensitive than the coronary artery to inhibition of net phospholipid synthesis by aminomethylpropanol. Addition of 3-amino-l-propanol, dimethylaminoisopropanol and triethanol-amine in concentrations of 0.001, 0.01 and 0.1 M each resulted in inhibition of [ 32 P]-phosphate incorporation into the phospholipids of the coronary arteries; there was little evidence of specific inhibition of any of the individual phospholipid classes studied.