Renal mRNA response to reduced perfusion pressure conserved despite denervation in mature ovine fetuses

We hypothesized that renal denervation in mature ovine fetuses reduces reni n mRNA response to 24 h of reduced renal perfusion pressure (RPP). Seven oc cluder (O) (132.4 +/- 1.2 days gestation) and six control (C) (131.5 +/- 1. 2 days gestation) fetuses underwent left renal denervation. Postoperatively , O fetuses experienced 24 h of reduced RPP by suprarenal aortic occlusion. Femoral arterial blood pressure (FAB) and plasma active renin (pARC) and p rorenin (pPRC) concentrations were obtained hourly for 6 h and at h 23 and 24. Renin mRNA was measured by RNase protection assay. We quantitated renin containing glomeruli by immunocytochemistry. Variables were compared by AN OVA. Mean O group FAB reduction from baseline was -6.60 +/- 0.41 mmHg. pARC and pPRC increased with occlusion, renal ARC and renal PRC1 did not increa se with occlusion. No effect in renin mRNA or number of positive glomeruli was noted with denervation in the basal state; however, significant increas es were noted in response to RPP irrespective of innervation status. In con clusion, 24 h or reduced RPP in mature ovine fetus increases renal renin mR NA and the immunocytochemical expression of renin. This response is conserv ed despite denervation.