Localization of sites of enhanced expression of endothelin-1 in the kidney of DOCA-salt hypertensive rats.

Although the role of endothelin-1, a potent vasoconstrictor peptide, in hypertension remains unclear, there is evidence of its involvement in deoxycorticosterone acetate (DOCA)-salt hypertensive rats, in which enhanced vascular production of endothelin-1 has been documented. The study presented here examined endothelin-1 gene expression in the kidney in DOCA-salt hypertensive rats by in situ hybridization histochemistry. A high specific activity 35S-labeled complementary RNA probe was used. Significant increases in abundance of endothelin-1 mRNA transcripts were found in the endothelium of renal vessels, and in capillary endothelial and mesangial cells of glomeruli of the remaining kidney of DOCA-salt hypertensive rats, in comparison with unilaterally nephrectomized control rats. Enhanced expression of the endothelin-1 gene in the kidney of DOCA-salt hypertensive rats may participate in abnormalities of renal function in this model of hypertension, and thus contribute to the development and maintenance of elevated blood pressure.