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Increased c‐Fos in medullary cardiovascular nuclei in acute and chronic renal wrap hypertension
Author(s) -
Cunningham J. Thomas,
Fleming Tiffany,
Penny Maurice L.,
HerreraRosales Myrna,
Mifflin Steven W.
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.a1205-d
Subject(s) - medicine , endocrinology , blood pressure , baroreflex , kidney , renal medulla , renal function , rostral ventrolateral medulla , staining , nephrectomy , renal cortex , heart rate , pathology
Renal wrap hypertension is characterized by sodium sensitivity, increased sympathetic outflow, and altered baroreflex function. The present study used c‐Fos staining to determine if more neurons are active in brainstem cardiovascular regions in this form of hypertension. Hypertension was produced using a unilateral nephrectomy, renal wrap procedure. Sham operated controls and 1 wk and 4 wk hypertensive rats were perfused and brainstems sectioned coronally (40 um). The sections were processed for c‐Fos immunocytochemistry (Oncogene AB‐5). Mean arterial pressures were 103 ± 2 mmHg for sham (n = 6), 138 ± 4 for 1 wk renal wrap (n=6), and 159 ± 6 for 4 wk renal wrap (n=6). Renal wrap hypertension was associated with a significant increase in c‐Fos staining in the NTS (sham 3 ± 1; 1 wk 12 ± 3; 4 wk 36 ± 3; P < 0.01) with 4 wk renal wrap significantly higher than 1 wk renal wrap. Similar increases were observed in the RVLM (sham 2 ± 1; 1 wk 9 ± 2; 4 wk 17 ± 2; P < 0.01). In the CVLM, c‐Fos staining was significantly increased in rats with hypertension but there were no differences between 1wk and 4 wk groups (sham 3 ± 1; 1 wk 6 ± 0.4; 4 wk 7 ± 1; P < 0.01). Changes in c‐Fos staining were not observed in the area postrema. Renal wrap hypertension was associated with significant increases in c‐Fos staining in the NTS and the RVLM that were related to the level of blood pressure. The failure to observe similar changes in the CVLM could be related to baroreceptor resetting at this site or reflect convergence of NTS inputs to this region. Supported by HL067529 &HL56637