EFFECTS OF NOREPINEPHRINE ON NMDA-INDUCED NEUROTOXICITY IN CEREBELLARGRANULAR-CELL CULTURE OF RAT PUPS

In this study, norepinephrine was tested in 0.1, 1, 10, 25 and 50 mu M doses in 100 mu M NMDA toxicity on cerebellar granular cell culture o f rats. NMDA in 100 mu M concentration induced cell death significantl y with respect to controls. Death cell population was 1.08 +/- 0.44% i n control and 22.15 +/- 2.46% in 100 mu M NMDA (P < 0.0001). None of t he norepinephrine concentrations administrated 15 min prior to NMDA wa s able to reduce death cell scores to control levels. Results were 8.7 5 +/- 0.83% in 0.1 mu M, 7.0 +/- 1.01% in 1 mu M, 17.25 +/- 1.31% in 1 0 mu M, 35.5 +/- 1.38% in 25 mu M and 17.9 +/- 1.72% in 50 mu M norepi nephrine plus 100 mu M NMDA administrated groups (P < 0.0001 for all w ith respect to control). Labetalol, as an alpha and beta blocker in 0. 5 mu M concentration which was given 15 min prior to norepinephrine wa s able to block the effects of it. In comparison with 100 mu M NMDA ad ministered group, only low doses of norepinephrine reduced the death c ell scores significantly (for 0.1 and 1 mu M norepinephrine plus NMDA groups; P < 0.0001). For 10 and 50 mu M norepinephrine plus NMDA group s, death cell scores were found statistically insignificant from the N MDA-administered group (P > 0.05 for both) while for the 25 mu M norep inephrine plus NMDA group, the death cell score was found to be statis tically increased (P < 0.0001). (C) Elsevier, Paris.