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Sex differences in the renal and cardiovascular responses to aldosterone: role of nitric oxide
Author(s) -
Roesch Darren M,
Shi Min,
Verbalis Joseph G,
Ecelbarger Carolyn A,
Sandberg Kathryn
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1194
Subject(s) - medicine , endocrinology , nitric oxide , aldosterone , blood pressure , chemistry , kidney
Renal escape (RE) from aldosterone (A) is associated with a paradoxical nitric oxide (NO)‐induced increase in the renal abundance (RA) of the Na/H exchanger 3 (NHE3). We hypothesized there are sex differences (SD) in the ability of rats to respond to chronic A infusion with regard to NHE3, NO, and blood pressure (BP). Vehicle or A (200 μg/day) was infused in male (M) and female (F) rats fed a 1% NaCl diet for 4 weeks: M control (n=5, MC), M infused with A (n=6, MA), F control (n=6, FC), and F infused with A (n=6, FA). There was an interaction (p<0.01) between the effects of sex (S) and treatment (T) on BP as measured by radiotelemetry. BP was 104±3 mmHg in MC and was increased (p<0.01) to 135±4 mmHg in MA. In contrast, BP was 107±4 mmHg in FC and was not different (108±6 mmHg) in FA. There was also an interaction (p=002) between the effects of S and T on the whole kidney RA of NHE3; A infusion increased (p=0.02) NHE3 in M, but not F, suggesting increased activation of A escape in M. In addition, there was an interaction (p=0.03) between the effects of S and T on total plasma nitrites and nitrates (NO x ). NO x was 242±44 μM in MC rats, and was reduced (p=0.03) to 74±26 μM in MA rats, suggesting an A‐induced decrease in circulating NO contributes to hypertension (HT) in MA. In contrast, NO x was 28±5 in FC and not different in FA (39±12 μM). T did not affect RA of eNOS, indicating that the previously characterized acute increase in RA of eNOS in RE is not evident in these chronically treated animals. However, the RA of eNOS was reduced (p=0.003) in F as compared to M, further supporting a reduced physiological role for both circulating and renal NO in F. In summary, M develop HT and undergo RE in response to A, but F do not develop HT and thus do not need to undergo renal escape. Supported by AG022624.