The features of blood supply to the rat medulla during pathological periodic apneustic respiration provoked by sodium hydroxybutyrate

Abstract

The model of periodic apneustic respiration provoked by sodium hydroxybutyrate was used in acute experiments on anaesthetized mongrel male albino rats to examine the blood supply to the region of respiratory center in the brain stem. The development of periodic pathological respiration was associated with specific periodic oscillations of 1) blood flow in the brain stem microvasculature and 2) oxygenation of the nervous tissue following the respiration rhythm. Under these conditions, both blood supply to and venous outflow from the brain were augmented. The study suggested that the characteristic oscillations of blood supply to the brain at the respiration rhythm emerge not only in the brain stem but also in other cerebral regions. Probably, they are caused by oscillations of venous outflow induced by the suction effect of the chest cavity during inspiration.