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Endogenous nitric oxide synthase (NOS) inhibitor, asymmetrical dimethylarginine (ADMA), in the paraventricular nucleus (PVN) and plasma in renal wrap hypertension
Author(s) -
Northcott Carrie A,
Haywood Joseph R,
D'Alecy Louis G,
Billecke Scott S
Publication year - 2008
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.22.2_supplement.40
Subject(s) - medicine , asymmetric dimethylarginine , endocrinology , blood pressure , chemistry , nitric oxide , endogeny , nitric oxide synthase , renal function , arginine , biochemistry , amino acid
ADMA is an endogenous NOS inhibitor. NO plays a critical role in blood pressure maintenance. Elevated plasma ADMA levels occur in hypertension (HBP); moreover, the PVN NOS system is dysfunctional. Thus it was hypothesized there would be elevated levels of ADMA in the PVN and plasma in renal wrap HBP. Plasma and PVN were isolated from hypertensive renal wrap and sham rats during the onset (7 day post surgery) and sustained phases (28 day) of hypertension (Mean arterial pressure, 7 day: 142 ± 7 vs. 105 ± 4 mm Hg; 28 day: 126 ± 9 vs. 94 ± 3 mm Hg). ADMA and symmetrical dimethylarginine (SMDA) were analyzed by high pressure liquid chromatography. ADMA and SDMA were measured in the PVN in both renal wrap and sham animals. During the onset of HBP there was no difference in ADMA in either PVN or plasma; however, there were significantly lower SDMA levels in the PVN from hypertensive animals (0.07 ± 0.02 vs. 0.13 ± 0.02 μM; p ≤ 0.05); no change in plasma SDMA was found. During sustained HBP there were significantly greater levels of plasma ADMA and SDMA (ADMA: 0.95 ± 0.04 vs. 0.82 ± 0.05 μM; SDMA: 0.42 ± 0.02 vs. 0.33 ± 0.02 μM; p ≤ 0.05), and a trend for lower PVN ADMA (0.18 ± 0.02 vs. 0.22 ± 0.02 μM; p < 0.07); no difference in PVN SDMA levels were found. These data demonstrate increased plasma ADMA in HBP. However, there are lower levels of PVN localized ADMA during HBP; potentially attempting to restore NO levels in the PVN.