GENE-EXPRESSION OF ENDOTHELIN RECEPTORS IN AORTIC-CELLS FROM CYCLOSPORINE-INDUCED HYPERTENSIVE RATS

1. We examined preproendothelin-1, ET(A) and ET(B) receptor mRNA level s in aortic endothelial and smooth muscle cells from cyclosporine (CyA )-induced hypertensive rats using the reverse transcription polymerase chain reaction method, 2. Aortic endothelial preproendothelin-1 mRNA expression was about 1.5-fold higher, while that of ET(B) receptor mRN A was markedly decreased in CgA-treated rats compared with those in co ntrols. 3. The expression of ET(A) receptor mRNA in smooth muscle cell s from CyA-induced hypertensive rats was increased about two-fold over that in cells from control animals. 4. Thus, increased endothelial pr eproendothelin-1, and ET(A) receptor mRNA levels in smooth muscle cell s, which are concomitant with the decrease in ET(B) receptor mRNA leve ls in endothelium, mag contribute to CyA-induced hypertension in rats.