It was shown in experiments on conscious cats 1-2 days after intracerebral hemorrhage (administration of 2 ml autogenous blood in the internal capsule of the right hemisphere) that intravenous injection of 50 mg/kg gutimin led to an increase in the brain blood supply. The increased local blood flow was recorded in the cortex, thalamus of the affected hemisphere, particularly in the midbrain reticular formation. Experiments in vitro demonstrated that gutimin had a direct dilatatory action on isolated strips of the cat internal maxillary artery, with this action being determined by inhibition of the metabolism of exo- and intracellular calcium.