Suppression of water shift into intracellular space by TA-3090 (calcium entry blocker) measured with NMR.

In order to clarify the effects of TA-3090 (calcium entry blocker) on the suppression of water after ischaemic events, 16 measurements of T2f were continuously performed on brain biopsy (for 2-60 min) obtained from treated and control Wistar rats. The time constant (k) and NMR parameters (T2f,(O) delta T2f, T2fmax(T2f(O) + delta T2f) were obtained from 16 values of T2f. The values of k in Wistar rats treated with intravenously administrated TA-3090 (0.5 mg/kg) were significantly prolonged as compared to that of control. There were no significant differences of maximum prolongation of T2f(T2fmax(T2f(O) + delta T2f) among three groups. Since the prolongation of T2f after biopsy reflects the water shift from extra to intracellular space, the increments of time constant indicates that TA-3090 suppresses the water shift into intracellular space. Our present results suggest that TA-3090 prevents some processes involved in irreversible cell damage and suppresses the cytotoxic brain oedema in the incomplete ischaemic area where non-competitive calcium channel is inactive.