The Effects of Emopamil on Neurologic and Neuropathologic Outcomes Following Transient Global Ischemia in Rabbits

Abstract

Background: Previous studies have suggested that the phenylalkylamine calcium channel blocker, emopamil, may have neuroprotective properties. This study was designed to examine the effects of emopamil on the neurologic and neuropathologic outcome after transient global cerebral ischemia. Methods: New Zealand white rabbits were randomly assigned to one of the following groups: emopamil group (n = 6; emopamil 1 mg/kg bolus prior to ischemia and then 0.1 mg/kg/min for 1 hour), hypothermia group (n = 7; 29oC prior to, during and until 1 hour after ischemia), or control group (n = 7). All rabbits were subjected to 6.25 minutes of global cerebral ischemia produced by a neck tourniquet inflation (20 psi) combined with hypotension during halothane anesthesia. Neurologic deficit scoring was done at 24 hours and 48 hours after ischemia. The rabbits were then euthanized and perfused with 10% formalin. Coronal sections of brain (6m) were stained with hematoxylin and eosin. The sections were scored for evidence of ischemic injury by two observers blinded as to the experimental group. Results: The hypothermia group had significantly less evidence of neurologic and neuropathologic injury when compared to the control group (P 0.05). There were no significant differences between the control and emopamil groups in neurologic or neuropathologic outcome. Conclusions: These results suggest that the peri-ischemic administration of emopamil had no effect on their neurologic or neuropathologic outcome in this model, but, as anticipated, hypothermia was neuroprotective.