The Effects Of Renal Denervation On Renalase And Tyrosine Hydroxylase Expression In Adult Spontaneously Hypertensive Rats

Objective:To investigate differences of renal renalase and (Tyrosine hydroxylase, TH) expression between spontaneous hypert-ensive rats (SHR)and Wistar Kyoto rats (WKY)rats,and the impact of renal denervation on the blood pressure, plasma renalase content and expression of renalase and TH in the kidney of spontaneous hypert-ensive rats (SHR) and to explore the mechanism of renal denervation lowering blood pressure.Methods:SH rats (n=48) were randomly assigned into baseline group, surgery (renal denervation) group, sham group and control group. WKY rats matched in age (n=12) served as baseline control group. All rats were housed until they were12weeks old. Then, the rats in baseline group and WKY group were sacrificed.blood samples and kidneys were collected for examination. In the renal denervation group, sham group and control group, the blood pressure was continuously monitored. At1st week and6st week after renal denervation,6rats in each group were sacrificed and blood, kidneys were collected for examination. Blood pressure of each group were measured by tail cuff method.ELISA was employed to measure the plasma renalase.Protein of renalase and tyrosine hydroxylase in kidney were determined by immunohistochemisry. Western blot assay detect the expression of TH and renalase in the kidney, and norepinephrine (Ne) were determined by HPLC.Results:1. When compared with WKY rats, SH rats in the baseline group had significantly increased blood pressure and markedly elevated TH protein expression (P<0.05), but plasma renalase content and protein expression of renalase in the kidney was dramatically reduced (P<0.05).2.1st week after surgery, the blood pressure, plasma Na content,Ne and TH protein expression of kidnety in the surgery group dramatically reduced when compared with sham group and control group (P<0.05). In the surgery group, the renalase level and expression in kidney was markedly increased when compared with sham group and control group (P<0.05). There was no significant difference between the sham operation and control rats in the above parameter (P>0.05).3.6st week after renal denervation, the blood pressure and TH level in the surgery group was significantly increased but the renalase content and expression markedly reduced when compared with those at week1(P<0.05), but there was no marked differences among surgery group, sham group and control group except TH and Ne level (P>0.05). Moreover, no pronounced differences in above variables were found between sham group and control group at any time point (P>0.05).Conclusion:In spontaneously hypertensive rats, the elevated blood pressure was related to the deficiency of renalase and rised tyrosine hydroxylase in kidney. Renal denervation can lower blood pressure, which may be attributed to the suppression of tyrosine hydroxylase, increase in plasma renalase content and renalase expression in the kidney.