Chronic exposure to intermittent hypoxia (CIH) increases carotid sinus nerve activity in
normoxia and in response to acute hypoxia. We hypothesized that CIH augments basal and
chemoreflex-stimulated sympathetic outflow through an angiotensin receptor-dependent
mechanism. Rats were exposed to CIH for 28 days: a subset was treated with losartan.
Then, lumbar sympathetic activity was recorded under anesthesia during 20-s apneas,
isocapnic hypoxia, and potassium cyanide. We measured carotid body superoxide …