[Effect of prolactin on the secretion of milk casein: metabolism of arachidonic acid].
Mammary gland fragments were incubated in the presence of prolactin and arachidonic acid which stimulate casein secretion. The effects of these stimuli in the presence of agents that influence arachidonic acid metabolism were investigated. Chloroquine, a blocker of phospholipase A2 activity, decreased prolactin but not arachidonic acid stimulation of casein secretion. Phospholipase A2 markedly stimulated casein secretion. Nordihydroguaiaretic acid (NDGA), an antioxidant that inhibits lipoxygenase, blocked the stimulating effect of prolactin and arachidonic acid. Ultrastructural studies indicated that phospholipase A2-induced stimulation of secretion was comparable to that of prolactin but that arachidonic acid-induced stimulation did not involve the same Golgi membrane modifications. These studies suggest that prolactin and phospholipase A2 stimulate secretion by a common way, and that arachidonic acid interferes with secretion by metabolic products of the lipoxygenase pathway.
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology*; D002396:Catechols / Q000494:pharmacology; D002738:Chloroquine / Q000494:pharmacology; D005089:Exocytosis / Q000187:drug effects; D005260:Female; D007700:Kinetics; D016859:Lipoxygenase Inhibitors; D008321:Mammary Glands, Animal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009637:Masoprocol; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D054467:Phospholipases A2; D011388:Prolactin / Q000494:pharmacology; D051381:Rats; D012636:Secretory Rate / Q000187:drug effects
D001095:Arachidonic Acids; D002396:Catechols; D016859:Lipoxygenase Inhibitors; D016718:Arachidonic Acid; D009637:Masoprocol; D002738:Chloroquine; D011388:Prolactin; D010741:Phospholipases A; D054467:Phospholipases A2
Effet de la prolactine sur la sécrétion des caséines du lait: métabolisme de l'acide arachidonique.