NORADRENALINE INHIBITS THE PROGRAMMED CELL-DEATH INDUCED BY 1,25-DIHYDROXYVITAMIN-D-3 IN GLIOMA

The rat glioma cell line C6.9 has been recently reported to respond to 1,25-dihydroxyvitamin D-3 (1,25(OH)(2)D-3) by the induction of a prog rammed cell death. Since, in vivo, glial cells are thought to be expos ed to several neurotransmitters, we investigated the possibility of a neurotransmitter-mediated inhibition of this active cell death process . Noradrenaline and the beta-adrenoceptor agonist isoproterenol showed significant inhibition of the 1,25(OH)(2)D-3-induced programmed cell death. The beta-adrenoceptor antagonist propanolol reversed this inhib ition, while the alpha-adrenoceptor antagonist yohimbin was devoid of any effect. This suggests that the efficiency of antiproliferative vit amin D-related therapies could be influenced by endogenous levels of n oradrenaline.