Cyclosporine A-induced prostacyclin release is maintained by extracellular calcium in rat aortic endothelial cells: role of protein kinase C.
Chronic treatment with the immunosuppressive drug Cyclosporine A (CsA) is associated with increased intracellular calcium in vascular smooth muscle cells, which may activate phospholipase A2. We used rat aortic endothelial cells to investigate the role of protein kinase C (PKC) in CsA-induced prostacyclin (PGI2) release. CsA (10(-9) M) produced a significant increase in PGI2 release. CsA-induced PGI2 release were inhibited 80-85% by 10(-9) M, and 99-100% by 10(-6) M pretreatment doses of any of three different PKC inhibitors, i.e. 1-(5-isoquinolinesulfonylmethyl)piperazine(H7), staurosporine or 1-(5-isoquinolinesulfonyl)piperazine. Pretreatment with (10(-9) M) of diltiazem (a voltage-sensitive L-type calcium channel blocker) completely inhibited both CsA-induced PGI2 release. Conversely, pretreatment with (10(-9) M) of thapsigargin (an intracellular calcium channel blocker) did not alter the action of CsA. These results strongly suggest that PKC, in association with an influx of extracellular calcium, mediates CsA-induced PGI2 release in rat aortic endothelial cells.
Oriji
G K
GK
Department of Biology, College of Science and Health, William Paterson University, Wayne, NJ 07470, USA.
D000818:Animals; D001011:Aorta / Q000166:cytology / Q000201:enzymology; D002118:Calcium / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D016572:Cyclosporine / Q000494:pharmacology*; D004110:Diltiazem / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000201:enzymology*; D011464:Epoprostenol / Q000378:metabolism*; D008297:Male; D011493:Protein Kinase C / Q000502:physiology; D051381:Rats; D019284:Thapsigargin / Q000494:pharmacology
D002121:Calcium Channel Blockers; D019284:Thapsigargin; D016572:Cyclosporine; D011464:Epoprostenol; D011493:Protein Kinase C; D004110:Diltiazem; D002118:Calcium