[Contribution of calmodulin to renin release in spontaneously hypertensive rats]

A comparative study was designed to evaluate the contribution of calmodulin to renin release from isolated glomeruli of spontaneously hypertensive rats (SHR, Okamoto and Aoki). Male 7-week-old SHR and age-matched control Wistar-Kyoto rat (WKY) were used in the present study. Glomeruli were isolated by the method of Beierwaltes et al. Isolated glomeruli were placed within the superfusion chamber and perfused with Krebs-Ringer solution at a constant flow of 0.3 ml/minute at 37 degrees C. Renin release was increased by calmodulin inhibitor, W-7 in both SHR and WKY. SHR showed higher maximal levels of renin release by W-7 compared to WKY. This result indicates that calmodulin plays an inhibitory role in renin release from juxtaglomerular cells. Calmodulin-mediated suppression mechanism in renin release is augmented in SHR.