The kidney has both afferent (sensory) and efferent (sympathetic) nerves that can influence renal function. Renal innervation has been shown to play a role in the pathogenesis of many forms of
hypertension.
Hypertension and
flank pain are common clinical manifestations of autosomal dominant (AD)
polycystic kidney disease (PKD). We hypothesize that renal innervation contributes to the
hypertension and progression of cystic change in rodent PKD. In the present study, the contribution of renal innervation to
hypertension and progression of renal histopathology and dysfunction was assessed in male Han:SPRD-Cy/+ rats with
ADPKD. At 4 weeks of age, male offspring from crosses of heterozygotes (Cy/+) were randomized into either 1) bilateral surgical renal
denervation, 2) surgical
sham denervation control, or 3) nonoperated control groups. A midline
laparotomy was performed to allow the renal
denervation (i.e., physical stripping of the nerves and painting the artery with
phenol/alcohol). Blood pressure (tail cuff method), renal function (BUN) and histology were assessed at 8 weeks of age. Bilateral renal
denervation reduced the
cystic kidney size,
cyst volume density, systolic blood pressure, and improved renal function (BUN) as compared with nonoperated controls. Operated control cystic rats had kidney weights,
cyst volume densities, systolic blood pressures, and plasma BUN levels that were intermediate between those in the denervated animals and the nonoperated controls. The denervated group had a reduced systolic blood pressure compared with the operated control animals, indicating that the renal innervations was a major contributor to the
hypertension in this model of
ADPKD. Renal
denervation was efficacious in reducing some pathology, including
hypertension, renal enlargement, and cystic pathology. However,
sham operation also affected the cystic disease but to a lesser extent. We hypothesize that the amelioration of
hypertension in Cy/+ rats was due to the effects of renal
denervation on the renin angiotensin system.