Renal nerves and leukocyte infiltration in the kidney during salt-sensitive hypertension

Abstract

Based on previous studies suggesting a role of renal nerves in renal inflammation, the present studies were performed to test the hypothesis that renal nerves mediate renal damage in Dahl salt-sensitive (SS) hypertension by increasing renal leukocyte infiltration. Experiments were performed in Dahl SS rats with bilateral renal denervation (RDN) and bilateral sham operation (n ± 10 or 11 per group) and with unilateral RDN and contralateral sham operation (n ± 10). After denervation, rats were switched from a low-salt 0.4% NaCl (LS) diet to a high-salt 4% NaCl (HS) diet and maintained on HS diet for 21 days. Bilateral RDN reduced the magnitude of hypertension assessed by radiotelemetry in Dahl SS rats compared with sham-operated rats (mean arterial pressure 140.9 > 4.8 mmHg and 159.7 > 3.5 mmHg, respectively) and reduced proteinuria at day 21 of HS diet. However, assessment of renal leukocyte infiltration demonstrated no significant effect of bilateral RDN on the number of infiltrating leukocytes (RDN 3.6 > 0.5 < 106 vs. sham operated 4.3 > 0.3 < 106 CD45< cells) or any of the subsets examined by flow cytometry. The unilateral RDN experiment showed no effect of RDN on the renal infiltration of leukocytes (RDN 6.5 > 0.9 < 106 vs. sham operated 6.1 > 1.1 < 106 CD45