Phospholipases and the effect of prolactin on uridine incorporation into RNA in mammary gland explants of mice.
The possible effects of phospholipase A and phospholipase C on the rate of uridine incorporation into RNA in mammary gland explants of mice were tested. Phospholipase C had no effect on the rate of uridine incorporation, but it did suppress the action of prolactin on this metabolic parameter. In contrast, phospholipase A was found to stimulate the rate of uridine incorporation into RNA in a manner similar to that of prolactin. The time-courses for the onset of the prolactin and phospholipase A effects were the same. Also, the phospholipase A effect was nonadditive to the effect produced by a maximally stimulatory concentration of prolactin. Finally it was observed that, like the prolactin effect, the phospholipase A effect was abolished by incubation with dibutyryl cyclic AMP, theophylline, quinine, indomethacin and prostaglandin E1. Further, the phospholipase A effect was nonadditive to the prolactin-like effects produced by the cyclic GMP, prostaglandin F2alpha or arachidonic acid. These data therefore suggest that prolactin and phospholipase A stimulate RNA synthesis in mammary gland explants via similar processes.
D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D003994:Bucladesine / Q000494:pharmacology; D006152:Cyclic GMP / Q000494:pharmacology; D005260:Female; D007213:Indomethacin / Q000494:pharmacology; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000378:metabolism*; D009924:Organ Culture Techniques; D010740:Phospholipases / Q000494:pharmacology*; D011247:Pregnancy; D011388:Prolactin / Q000494:pharmacology*; D011458:Prostaglandins E / Q000494:pharmacology; D011803:Quinine / Q000494:pharmacology; D012313:RNA / Q000096:biosynthesis*; D051381:Rats; D013806:Theophylline / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects*; D014529:Uridine / Q000378:metabolism*
D001095:Arachidonic Acids; D011458:Prostaglandins E; D012313:RNA; D003994:Bucladesine; D011388:Prolactin; D011803:Quinine; D013806:Theophylline; D010740:Phospholipases; D006152:Cyclic GMP; D014529:Uridine; D007213:Indomethacin