ISOFLURANE REDUCES MICROTUBULE-ASSOCIATED PROTEIN-2 DEGRADATION COMPARED WITH HALOTHANE DURING FOREBRAIN ISCHEMIA IN THE RAT

One of the most prominent features of the early phase of cerebral isch aemia is the immunohistochemical collapse of cytoskeletal proteins. Am ong these proteins, microtubule-associated protein 2 (MtP2) has been s hown to be vulnerable to ischaemic injuries. In order to identify a su itable volatile anaesthetic on the basis of cytoskeletal protein break down during cerebral ischaemia, we have compared the effects of isoflu rane and halothane on MtP2 degradation in rats. Under equipotent isofl urane or halothane anaesthesia, forebrain ischaemia was induced by occ lusion of the bilateral common carotid artery, combined with a decreas e in mean arterial pressure to 50 mm Hg. After 20 min of ischaemia, th e frontoparietal cortex, brainstem, hippocampus and cerebellum were re moved separately and homogenized. MtP2 from each region was measured u sing an enzyme-linked immunosorbent assay. MtP2 degradation in the fro ntoparietal cortex and hippocampus was significantly (P < 0.05 and P < 0.01) less with isoflurane anaesthesia (75.6 (SD 10.7)% and 72.3 (12. 8)%, respectively) than with halothane (65.0 (13.1)% and 54.7 (13.9)%, respectively).