BENEFICIAL VASCULAR AND METABOLIC EFFECTS OF COBALT-ATP IN SPONTANEOUSLY HYPERTENSIVE RABBITS WITH DIFFUSE CHRONIC CEREBRAL-ISCHEMIA

The in vivo effects of adenosine triphosphate (ATP) have not been inve stigated in cerebrovascular diseases. The use of the long-acting cobal t-ATP complex (Co-ATP) permits us to observe the effects of ATP withou t the influence of its metabolites. This study was designed to compare the effects of intravenous Co-ATP on the cerebral blood flow (CBF), p olarographically detected oxygen currents (O(2)a), mean arterial blood pressure (MABP), heart rate, respiration rate, cerebral electrical ac tivity, arterial blood gases, pH, and glucose in 13 normotensive (NT) rabbits to those in 14 stroke-prone spontaneously hypertensive (HT) an imals. CBF was measured by the hydrogen and heat clearance methods. In response to Co-ATP, MABP decreased and CBF increased significantly in both groups. The decrease in MABP was more marked in HT rabbits, whil e CBF response was 25% smaller than in NT animals. The ratio of O(2)a to CBF diminished moderately and simultaneously with the CBF increase in NT rabbits. In HT rabbits, the decrease in O(2)a/CBF was larger and began when CBF response reached its maximum. We suggest that despite the restricted CBF response, long-acting ATP should still be taken int o consideration as a supplementary treatment of hypertensive encephalo pathy because of its beneficial effects on cerebral metabolism and hyp ertension.