The water channel aquaporin-1 contributes to renin cell recruitment during chronic stimulation of renin production.

The water channel aquaporin-1 contributes to renin cell recruitment during chronic stimulation of renin production. Am J Physiol Renal Physiol. 2014 Oct 22; Authors: Tinning AR, Jensen BL, Schweda F, Machura K, Hansen PB, Stubbe J, Gramsbergen JB, Madsen K Abstract Processing and release of secretory granules involve water movement across granule membranes. It was hypothesized that the water channel aquaporin-1 (AQP-1) contributes directly to recruitment of renin-positive cells in the afferent arteriole. AQP1(-/-) and (+/+) mice were fed a low NaCl diet (LS, 0.004% w/w) for 7 days and given enalapril (ACEI, 0.1 mg/ml) in the drinking water for 3 days. There were no differences in plasma renin concentration at baseline. After LS-ACEI, plasma renin concentration increased markedly in both genotypes but was significantly lower in AQP1(-/-) compared to (+/+) mice. Tissue renin concentration was higher in AQP1(-/-) mice and renin mRNA level was not different between genotypes. Mean arterial blood pressure was not different at baseline and during low salt diet but decreased significantly in both genotypes after addition of ACEI; the response was faster in AQP1(-/-) but then stabilized at similar level. Renin release after 200 µL blood withdrawal was not different. Isoprenaline-stimulated renin release from isolated perfused kidneys did not differ between genotypes. Cortical tissue norepinephrine concentration was lower after LS-ACEI compa...
Source: American Journal of Physiology. Renal Physiology - Category: Physiology Authors: Tags: Am J Physiol Renal Physiol Source Type: research