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,(○) ∆ T2f, T2fmax(T2f(○) + ∆ 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(○) + ∆ 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.
KeywordsIntracellular Space Cereb Blood Flow Calcium Entry Blocker Nuclear Magnetic Resonance Parameter Water Shift
Unable to display preview. Download preview PDF.
- 6.Haida M, Shinohara Y, Yamamoto M, Taniguchi R, Ohsuga H, Fukuzaki M. A rapid shift of water from extracellular to intracellular space after total ischaemia by NMR (to be submitted)Google Scholar
- 7.Shinohara Y, Yamamoto M, Haida M, Taniguchi R (1989) Calcium antagonist and a rapid shift of water from extracellular to intracellular space after cerebral ischaemia. In: Hartmann A, Kuschinsky W (eds) Cerebral ischaemia and calcium. Springer, Berlin Heidelberg New York, pp 150–154Google Scholar
- 9.Makamura S, Ohashi M, Suzuki T, Sugawara Y, Usuki S, Takaiti O (1989) Metabolic fate of the new Ca+ + -channel blocking agent (+)-(2 s,3 s)-3-acetoxy-8-chloro-(2-(dimethylamino)ethyl2,3-dihydro-2-(4-methoxyphenyl)-2,5-benzothiazepin-4-(5 H)-one maleate. Arzneim-Forsch/Drug Res 39: 1100–108Google Scholar
- 10.Murata S, Kikkawa K, Yabana H, Nagao T (1988) Cardiovascular effects of a new 1,5-benzothiazepine calcium antagonist in anaesthetized dogs. Arzneim-Forsch/Drug Res 38: 521–525Google Scholar