Identification and partial characterization of phospholipases in isolated adrenocortical cells. The effects of synacthen [corticotropin-(1--24)-tetracosapeptide] and calcium ions.
Phospholipase A activity was determined in homogenates and subcellular fractions of trypsin-dispersed cat adrenocortical cells. At pH 7.4 homogenate phospholipid hydrolysis was activated by added Ca2+ and inhibited by EGTA. Phospholipid degradation in the presence and absence of Synacthen was completely blocked by EGTA. Ca2+-dependent activation of a membrane-bound phospholipase may be a critical control mechanism for regulating the molecular changes taking place during stimulation by Synacthen.
D000302:Adrenal Cortex / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D000311:Adrenal Glands / Q000201:enzymology*; D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002415:Cats; D003366:Cosyntropin / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D010740:Phospholipases / Q000378:metabolism*
D003366:Cosyntropin; D000324:Adrenocorticotropic Hormone; D010740:Phospholipases; D002118:Calcium