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Peripheral Chemoreceptors Contribute Significantly to Hypertension in Spontaneously Hypertensive Rats (SHR)
Author(s) -
Whiteis Carol A.,
Post Collin E.,
Morgan Donald A.,
Rahmouni Kamal,
Chapleau Mark W.,
Abboud Francois M.
Publication year - 2012
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.26.1_supplement.703.15
Subject(s) - glomus cell , medicine , carotid body , endocrinology , blood pressure , chemoreceptor , stimulation , peripheral , anesthesia , receptor
In carotid body glomus cells of young pre hypertensive SHR the overexpression of acid sensing ion channels increases their pH sensitivity and is associated with increased sympathetic nerve activity (Tan et al., Circ. Res. 2010). Here we tested the hypothesis that early resection of the carotid bodies might reduce hypertension in SHR. Under anesthesia both carotid bodies were resected (CBX) in young (<5 weeks) SHR and in their normotensive control WKY. Arterial blood pressure (BP) recorded using a tail cuff twice a week over a 5 month period was lower in SHR with CBX than in sham‐operated SHR (p<0.05 ANOVA). The 24 hour intra‐arterial BP recordings in awake rats at 23 weeks of age are below.Systolic BP (mmHg) Mean BP (mmHg) Sham CBX Sham CBXWKY 149±5 (n=5) 146±6 (n=6) 120±5 119±7 SHR 239±6 * (n=10) 202±8 * † (n=9) 185±3 * 159±6 * †* p<0.05 (SHR vs. WKY)† p<0.05 (CBX vs. Sham)Compared to WKY, the mean BP was 65±3 mmHg higher in SHR‐Sham and only 40±6 mmHg higher in SHR‐CBX. Under anesthesia ventilatory and renal nerve activity responses to chemoreceptor stimulation were measured. The left ventricular (LV) weight of SHR‐Sham (1.04±0.03 gm) was significantly greater (p<0.002) than that of SHR‐CBX (0.92±0.01) and WKY (0.91±0.01). Conclusion The contribution of the hypersensitive peripheral chemoreceptors to the increase in mean BP in SHR is estimated to be 38% and may account for most of the LV hypertrophy. (NIH/HL14388)