Correspondence between the time course of cerebral vasospasm and the level of cerebral dopamine-beta-hydroxylase in rabbits.

The aim of the study was to explore whether the biphasic time course of the vasospastic response following experimental subarachnoid hemorrhage is associated with any concomitant changes in the amount of cerebral dopamine beta-hydroxylase in the noradrenergic central nervous system. A single-hemorrhage animal model was used. Rabbits were sacrificed from day 1 to day 8 after subarachnoid hemorrhage. Intimal corrugation of the basilar artery and the amount of cerebral dopamine beta-hydroxylase in the hypothalamus and brain stem were measured each day. Vasospastic changes occurred in the biphasic manner following subarachnoid hemorrhage. More profound vasospastic corrugation occurred in the acute phase, followed by a slightly less intense corrugation in the chronic phase (between days 5 and 8 after the subarachnoid hemorrhage). Simultaneously, a clear concomitant biphasic time course developed in the form of an increased amount of dopamine-beta-hydroxylase in the noradrenergic nervous system of the rabbit hypothalamus and brain stem during the acute and chronic phases after the subarachnoid hemorrhage. Statistically significant correlation between basilar artery corrugation and the amount of dopamine beta-hydroxylase was found. These results suggest the possible role of the central sympathetic system in the pathogenesis of vasospasm. At the same time, this study demonstrates the chronological similarity of the vasospastic development after subarachnoid hemorrhage in the animal experimental model with the human time course of vasospasm.