Effect of pretreatment with the calcium antagonist nimodipine on local cerebral blood flow and histopathology after middle cerebral artery occlusion.

We used the [14C]iodoantipyrine autoradiography technique to study the effect of pretreatment with the calcium antagonist nimodipine on local cerebral blood flow (lCBF) in rats that underwent middle cerebral artery (MCA) occlusion. In untreated control animals there were profound localized reductions in 1CBF 30 minutes after MCA occlusion. These were most pronounced in neocortical areas and in the caudate nucleus ipsilateral to the MCA occlusion. In animals pretreated with nimodipine (1 microgram X kg-1 X min-1 for 30 minutes before and 30 minutes after MCA occlusion), the ipsilateral decrease in 1CBF in cortical regions was significantly less than that in control animals. The drug did not appear to alter 1CBF in the ipsilateral caudate nucleus. Neuropathological quantification of the ischemic damage present 3 hours after occlusion showed that nimodipine pretreatment reduced the volume and extent of cellular damage in the periphery but not in the core of the lesion.