Triacylglycerol lipase-mediated release of arachidonic acid for renal medullary prostaglandin synthesis.
The effect of triacylglycerol lipase or triarachidonin on the synthesis of prostaglandin E2 in rabbit kidney medulla slices was examined. Prostaglandin E2 generation was enhanced by exogenous triacylglycerol lipase, indicating that arachidonic acid released from medullary triacylglycerols is readily available for prostaglandin biosynthesis. Triarachidonin stimulated prostaglandin E2 production in a dose-dependent manner. Moreover, the kidney medulla slices showed triacylglycerol lipase activity using trimargarin as substrate. The addition of mepacrine made the stimulatory effect of triarachidonin on prostaglandin E2 formation more pronounced. Studies utilizing EGTA and p-bromophenacyl bromide revealed that triacylglycerol lipase of kidney medulla is independent of Ca2+ and sensitive to a sulfhydryl inhibitor. These results suggest the presence of triacylglycerol lipase and triacylglycerol as a possible candidate for providing free arachidonic acid to cyclooxygenase in kidney medulla.
D015117:5,8,11,14-Eicosatetraynoic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D015232:Dinoprostone; D004533:Egtazic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D007679:Kidney Medulla / Q000201:enzymology / Q000378:metabolism*; D008049:Lipase / Q000378:metabolism*; D011458:Prostaglandins E / Q000096:biosynthesis*; D011817:Rabbits; D014280:Triglycerides / Q000378:metabolism
D001095:Arachidonic Acids; D011458:Prostaglandins E; D014280:Triglycerides; D015117:5,8,11,14-Eicosatetraynoic Acid; C055297:Triarachidonin; D016718:Arachidonic Acid; D004533:Egtazic Acid; D008049:Lipase; D015232:Dinoprostone