Renin synthesis and secretion were investigated in mice with one hydronephrotic kidney. 2. Enalapril and Dup753 stimulated renin synthesis to a similar extent in the hydronephrotic and normal kidney. 3. Hydronephrosis did not prevent an increase in renin mRNA caused by enalapril and Dup753. 4. The results therefore indicate that the macula densa does not appear to be crucial for renin synthesis in the kidney under the inhibition of angiotensin II. 5. Thus angiotensin II plays an important role controlling renin gene expression in both the normal and hydronephrotic kidneys.
