Effects of renal denervation on endogenous ouabain in spontaneously hypertensive rats

PURPOSE: To investigate the role of renal denervation (RDN) on endogenous ouabain (EO) secretion in spontaneously hypertensive rats (SHR). METHODS: Sixteen 12-week-old male SHR were randomly separated into the renal denervation group (RDNX group) and sham operation group (sham group), and eight age-matched Wistar Kyoto rats (WKY) were served as control group. EO concentrations, the Na(+)- K(+)-ATPaseactivity, and the expression of Na(+)-K(+)-ATPase were assessed. RESULTS: EO levels in serum, kidneys and hypothalamus of sham group were higher than in RDNX group (p < 0.05). Renal Na(+)-K(+)-ATPase activity subjected to denervation surgery showed significantly reduction when compared with the sham groups (p < 0.05). A positive correlation existed between norepinephrine (NE) content and Na(+)-K(+)-ATPase activity in the kidney (r(2) = 0.579). Renal Na(+)-K(+)-ATPase α1 subunit mRNA expression was down-regulated in the RDNX group compared with the sham group (P < 0.05), while renal Na(+)-K(+)-ATPase α1 subunit mRNA expression was no statistical significance between the groups (P = 0.63). Immunohistochemical analysis showed that there were significant differences in the renal expression of Na(+)-K(+)-ATPasebetween the three groups (P < 0.05). CONCLUSIONS: These experiments demonstrate that RDN exerted an anti-hypertensive effect with reduction of EO levels and Na(+)-K(+)-ATPase activity and Na(+)-K(+)-ATPase α1 subunit expression of kidney in SHR.