Mortality and cerebral metabolism after bilateral carotid artery ligation in normotensive and spontaneously hypertensive rats.

Mortality and cerebral glycolytic metabolism were studied after bilateral ligation of the common carotid artery in normotensive Wistar rats (NTR), and spontaneously hypertensive rats (SHR) derived from Wistar strain. In the first 24 hours after occlusion of carotid arteries, 72 per cent of 108 SHR died, whereas it was fatal in only 16 per cent of 43 NTR. In SHR, cerebral lactate and cerebral lactate/pyruvate ratio (L/P ratio) increased by 12.4 and 12.1 times the control, respectively at five to six hours after ligation, and remained raised even in rats surviving for two to three days thereafter. Changes in cerebral lactate and L/P ratio were minimal in NTR. Cerebral ATP decreased markedly at five to six hours after ligation in SHR studied. These results indicate that bilateral carotid artery ligation causes severe brain damage in SHR but not in NTR, suggesting hypertension per se to be operative for the development of cerebral ischaemia.