Generalized cerebral vasoconstriction induced by intracarotid infusion of angiotensin II in the rabbit

摘要: This study investigated the influence of angiotensin II, perfused into one common carotid artery at a dose 0.065 μg/kg/min, on cerebrovascular resistance anesthetized rabbit by means complementary in vivo methods. Heat clearance and mass spectrometry measurements indicated that homolateral caudate nucleus induced significant decrease local blood flow (18.2 ± 9%), fall pO2 (14.2 5.3%) no change pCO2. The [14C]ethanol tissue sampling technique revealed all 10 structures sampled brain. was similar magnitude both ipsilateral contralateral hemisphere with regard to site injection. When expressed terms (CVR) allowing for slight increase pressure (< 10%), these results show II infusion an CVR 18–32%. We conclude that: (1) A unilateral intracarotid low induces increased vascular tone cerebral structures. (2) This action, being bilateral, cannot readily be explained direct action vessels view very recirculating concentration II(< 10−9M). hypothesis vasomotor central structure is discussed.