The role of phospholipids in the binding of oxytocin to its receptors in lactating rabbit mammary gland.
Phospholipase C (Clostridium welchii and Bacillus cereus) treatment of lactating rabbit mammary gland membranes (140,000 g pellet and sucrose density gradient purified plasma membranes) resulted in a large decrease in the binding of [3H]oxytocin to these subcellular fractions. This decrease was not due to a solubilization of oxytocin receptors but was the result of the removal of phospholipids which may participate in the hormone-receptor interaction. Phospholipase C treatment of the membrane fractions resulted in a dose-dependent removal of different classes of phospholipids. Sphingomyelin, phosphatidylcholine and phosphatidylethanolamine were removed by phospholipase C (C. welchii and B. cereus) treatment. No significant change was observed in the content of phosphatidylinositol. Phospholipase C from B. cereus reduced the content of phosphatidylserine, while the enzyme from C. welchii did not.
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D007774:Lactation; D008321:Mammary Glands, Animal / Q000378:metabolism* / Q000648:ultrastructure; D010121:Oxytocin / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D011247:Pregnancy; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018045:Receptors, Oxytocin; D013109:Sphingomyelins / Q000378:metabolism; D010738:Type C Phospholipases / Q000494:pharmacology
D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D011956:Receptors, Cell Surface; D018045:Receptors, Oxytocin; D013109:Sphingomyelins; D010121:Oxytocin; D010738:Type C Phospholipases