Differential sympathetic activation induced by intermittent hypoxia and sleep loss in rats: Action of angiotensin (1-7).

The present study attempted to evaluate the effects of chronic intermittent hypoxia (CIH) associated with sleep restriction in hemodynamic parameters and the plasma renin-angiotensin system. Wistar-Hannover rats were submitted to isolated CIH exposure (1000-1600 h), sleep restriction (1600-1000 h), defined as 18-h paradoxical sleep deprivation followed by 6-h sleep permission period and CIH associated to sleep restriction for 21 days. The CIH and sleep restriction group showed a preferential increase in renal sympathetic nervous system (rSNA) associated with a reduction in plasma angiotensin (1-7) concentrations. However, CIH-sleep restriction rats did not modify rSNA and showed a higher angiotensin (1-7) concentration when compared to isolated CIH and sleep restriction. These results suggest that CIH and sleep restriction impaired the cardiovascular system, and its association to sleep loss can modify these effects by partially restoring circulating angiotensin (1-7).