Influence of Nitric Oxide Synthesis Inhibition on Endothelin-1 and Its Receptor Expression in Rat Kidney / 대한신장학회잡지

ABSTRACT

BACKGROUND: The present study was aimed to evaluate the influence of nitric oxide(NO) synthesis inhibition on endothelin(ET) expression in rat kidney. METHODS: Male Sprague-Dawley rats were treated with N(G)-nitro-L-arginine methyl ester(L-NAME, 100 mg/L drinking water) for 4 weeks to inhibit the endogenous synthesis of NO. The tissue expression of ET-1, ET(A) receptor, and ET(B) receptor mRNA in the kidney was determined by reverse transcription-polymerase chain reaction. RESULTS: Tissue levels of NO metabolites were significantly decreased in the plasma and the kidney, along with the increased blood pressure. The expression of ET-1 mRNA was increased in the cortex, but not in the medulla. The expression of ET(A) and ET(B) receptor mRNA was not significantly altered either in the cortex or in the medulla. The plasma level of ET-1 peptide was significantly increased, along with the increased blood pressure, when L-NAME(200 microgram/kg per min, iv) was administered in an acute preparation of animals. Accordingly, the expression of ET-1 mRNA was increased in the cortex, whereas that of ET(A) and ET(B) receptor mRNA was not altered. CONCLUSION: These results suggest that enhanced activity of ET system induced by NO synthesis inhibition may be associated with hypertension although direct association between two factors is not confirmed.