Responses of Surface Arteries and Blood Flow of Ischemic and Nonischemic Cerebral Cortex to Aminophylline, Ergotamine Tartrate, and Acetazolamide

In cats in which one middle cerebral artery was occluded, cortical blood flow (CBF) was measured and the superficial cortical microvasculature was observed bilaterally before and after the intravenous injection of a vasoactive drug. Aminophylline produced decreased CBF in the nonischemic cerebral hemispheres of five of seven animals and arterial constriction in three. Ergotamine tartrate produced arterial constriction in the nonischemic hemispheres of four animals and decreased CBF in three. Neither drug consistently produced increased CBF in ischemic cerebral tissue. Acetazolamide caused vasodilatation in the nonischemic hemispheres of seven animals and increased CBF in five. Increased CBF was not due entirely to changes of PaCO2. CBF also increased in ischemic hemispheres of four of the seven animals given acetazolamide.