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Elevated sympathetic activity precedes the arterial hypertension in the Goldblatt model
Author(s) -
OliveiraSales Elizabeth B,
Abdala Ana PL,
Colombari Eduardo,
Campos Ruy R,
Paton Julian FR
Publication year - 2010
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.24.1_supplement.982.4
Subject(s) - medicine , endocrinology , blood pressure , respiratory system , perfusion , sympathetic nervous system
Despite the extensive use of the Goldblatt model of hypertension (two kidney one clip, 2K1C) sympathetic mechanisms responsible for both the development and maintenance of the elevated blood pressure remain unclear. We tested the hypothesis that sympathetic nerve activity (SNA) is elevated by the third week after clipping and before development of hypertension. Using the in situ working heart brainstem preparation, male Wistar rats were divided into three groups: Sham (n=7), and 2K1C (3 weeks) of which some were hypertensive (2K1C‐H, n=6) or and others normotensive (2K1C‐N, n=9) as determined a priori . At comparable perfusion rates, pressures were higher in both 2K1C groups (2K1C‐H: 76 ± 1; 2K1C‐N: 74 ± 3 vs Sham: 60 ± 2 mmHg, p< 0.05). The respiratory modulation of SNA was significantly elevated in both 2K‐1C groups (e.g. 2K1C‐H: 47.7 ± 6.1; 2K1C‐N: 32.8 ± 2.8 vs Sham: 20.5 ± 2.5 μV, p< 0.05). Pre‐collicular transection reduced SNA in all rat groups (2K1C‐H: 32.5 ± 7.5, 2K1C‐NH: 48 ± 6.9 vs Sham: 13.2 ± 1%, p< 0.05). Subsequent transection at the medullary‐spinal cord abolished SNA in Sham and 2K1C‐N but decreased it by 57± 5.5% in 2K1C‐H. We conclude, SNA can be raised prior to onset of hypertension by the 3 rd week after clipping and this, in part, originates from enhanced respiratory modulation. Supported by CAPES and British Heart Foundation.