Comparative effects of unilateral and bilateral carotid artery ligation in the spontaneously hypertensive rat.

Male and female, spontaneously hypertensive rats (SHR) with blood pressures ranging from 190-210 mmHg were subjected unilateral or bilateral carotid artery ligation. Representative numbers of animals were killed 2, 4, 6, 8, 10, 12, 24 and 48 hours later. Severe cerebral ischemia caused a significant and protracted increase in the pre-existent high blood pressure, the enzymes CPK, SGOT and LDH triglycerides, free fatty acids, glucose, and corticosterone. Despite these marked pathophysiologic changes, the brains of these animals were free of real damage except for cerebral edema and scattered petechiae. Some of the animals developed massive atrial thrombi and myocardial infarcts. It is suggested that severe cerebral ischemia precipitated the myocardial infarcts through the aegis of the hypothalamic-pituitary-adrenal stress response.