Objective: To study the effects of deltamethrin (DM) on cell survival rate and intracellular Ca(2+) ([Ca(2+)]i) concentration in primary cultured astrocytes of rat.
Methods: The cell survival rate was measured by Typan Blue assay; the intracellular [Ca(2+)]i concentration was determined by the fluorescent Ca(2+) indicator Fura-2/AM.
Results: The survival rate of astrocytes was decreased to 91.9% after astrocytes were incubated with 1 x 10(-5) mol/L DM for 72 h (P < 0.05). The cell survival rates were 89.0%, 84.8%, 81.2% and 79.2% respectively when astrocytes were administered with 1 x 10(-4) mol/L DM for 4, 12, 24 and 72 h, which were remarkably lower than control groups (P < 0.01). Comparing with controls and before DM treatment, sharp increases in [Ca(2+)]i concentration [(451.4 +/- 42.3), (536.9 +/- 47.5) and (870.9 +/- 100.5) nmol/L respectively] were observed when astrocytes were incubated with 1 x 10(-7), 1 x 10(-6) and 1 x 10(-5) mol/L DM for 5 minutes (P < 0.01). After astrocytes were treated with 1 x 10(-8), 1 x 10(-7), 1 x 10(-6), 1 x 10(-5) mol/L DM for 15 minutes, the [Ca(2+)]i concentrations were decreased to (124.3 +/- 6.0), (131.3 +/- 19.1), (118.9 +/- 1.4), (136.6 +/- 3.8) nmol/L respectively, which were significantly different from those of controls and before treatment. And this situation was almost keeping stable to 30 min.
Conclusion: The cell survival rate was decreased and the [Ca(2+)]i concentration was temporarily increased when astrocytes were treated with DM.