Altered renin release from isolated superfused rat glomeruli in DOCA-salt hypertensive rats.

The present study was designed to clarify the role of calcium in suppressed renin release in DOCA-salt hypertension. Rat glomeruli were isolated by the modified Beierwaltes' sieving method. The glomeruli were superfused with Krebs-Ringer solution. Basal levels of renin release were lower in the DOCA-salt hypertensive rats (1.16 +/- 0.27 ng/ATI/hr/hr/10(4) glomeruli, mean +/- SEM, n = 8) than in the control rats (1.92 +/- 0.18, p less than 0.01, n = 8). Perfusion with a calcium free solution containing EGTA and A23187 stimulated renin release in the DOCA-salt hypertensive and control rats. The maximum levels of renin release during the perfusion in DOCA-salt hypertensive rats (1.79 +/- 0.17, n = 8) were lower than those in control rats (10.60 +/- 1.85, p less than 0.01, n = 8). These results suggest that high levels of intracellular calcium might not contribute to the suppression of renin release in DOCA-salt hypertension.