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

Incorporation of [³²P]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 ³²P 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 [³²P]-phosphate incorporation into the phospholipids of the coronary arteries; there was little evidence of specific inhibition of any of the individual phospholipid classes studied.