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pH sensitivity of carotid body glomus cells is augmented in spontaneously hypertensive rats
Author(s) -
Tan Zhiyong,
Whiteis Carol A.,
Chapleau Mark W.,
Abboud Francois M.
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.21.6.a1407
Glomus cells in carotid body are peripheral arterial chemoreceptors activated by hypoxia, hypercapnia and low pH. Chemoreceptor sensitivity to hypoxia is enhanced in several pathological states including hypertension (1). We hypothesized that chemoreceptor sensitivity to decrease in pH is augmented in spontaneously hypertensive rats (SHR). Whole‐cell patch clamping was used to assess the pH sensitivity of glomus cells isolated from carotid bodies of five Sprague Dawley (SD) rats and five SHR at a young age of 4–6 weeks. At resting membrane potential (RMP), glomus cells (11 SD and 8 SHR) were perfused with acidic bath solutions with different pH levels. The RMP of glomus cells was more negative (−40.6±3.0 mV) in SHR than in SD rats (−28.0±2.9 mV) (P<0.05). Decreases in extracellular pH from 7.4 to 7.0, 6.5, 6.0 depolarized SHR glomus cells to a greater extent (13±1, 24±2, 33±3 mV) than SD glomus cells (7±1, 14±1, 20±1 mV) (P<0.05). We conclude that carotid body chemoreceptors in young SHR are hypersensitive to decreases in pH compared with chemoreceptors in age‐matched SD rats. This enhanced pH sensitivity of glomus cells may contribute to increased chemoreception drive and excessive sympathetic nerve activity in hypertension. [HL 14388]