THE EFFECT OF BAY-K-8644 ON CYTOTOXIC EDEMA INDUCED BY TOTAL ISCHEMIAOF RAT-BRAIN

The calcium channel activator BAY K-8644, a dihydropyridine (DHP) deri vative, has been shown to possess neurochemical and behavioral activit ies, but its effect on ischemic brain damage has remained unknown. Thi s report describes the effect of the drug on the progression of cytoto xic edema induced by total ischemia of the brain, evaluated by measuri ng the time constant, k, of elongation of the H-1-NMR relaxation time (T2) after brain biopsy. Twenty-six male Wistar rats were divided into four groups, (a) control (saline) group (n = 10), (b) BAY K-8644 vehi cle group (n = 4), (c) BAY K-8644 0.03 mg/kg group (n = 6) and (d) BAY K-8644 0.3 mg/kg group (n = 6). The k value of group (d), 18.2 +/- 5. 8 min (mean +/- SD), was significantly higher compared with those of g roups (a) 10.3 +/- 1.6, (b) 11.8 +/- 1.5 and (c) 9.8 +/- 3.3 min (p < 0.01 by ANOVA). These results indicate that BAY K-8644 delayed the pro gression of cytotoxic edema induced by total ischemia of the rat brain .