Lazaroids improve the survival of cultured rat embryonic mesencephalic neurones.

We have studied the effects of two lazaroids, U-74389G and U-83836E, on the survival of cultured rat dopamine neurones. Lazaroids are inhibitors of free radical formation and lipid peroxidation. Dissociated embryonic mesencephalic neurones were cultivated for 2 or 7 days under serum-free conditions with or without the addition of 0.3 microM of one of the lazaroids. Both lazaroids enhanced the survival of tyrosine hydroxylase immunoreactive, dopaminergic neurones both after 2 and 7 days in vitro to around 111-120% and 175-180% of controls, respectively. Since the total number of neurones was also increased following lazaroid treatment, it is unlikely that lazaroids exert their effects on only dopamine neurones. These findings suggest that oxidative stress plays an important role in the death of cultured embryonic dopamine neurones and that lazaroids may be potent neuroprotective agents in situations where dopaminergic neurones degenerate.