Centrally administered ouabain aggravates central sleep apneas.

The presence of endogenous digitalis-like factors in the central nervous system suggests their functional significance in the central nervous system. Three-day infusions of three-stepped doses of the digitalis agent ouabain (1-100 ng.kg body wt-1.h-1) into the lateral cerebral ventricle of freely moving rats caused a dose-dependent increase in the number of central-apneic episodes during rapid-eye-movement sleep without affecting the time spent in rapid-eye-movement sleep or basic respiratory rate. These results suggest that endogenous digitalis-like factors may be involved in the genesis of central sleep apneas.