EFFECT OF TRI-N-BUTYLTIN ON INTRACELLULAR CA2+ CONCENTRATION OF RAT CEREBELLAR NEURONS

The effect of tri-n-butyltin on the intracellular Ca2+ concentration ([Ca2+]i) of cerebellar neurons dissociated from rats was examined using fluo-3 and a flow cytometer. Tri-n-butyltin at 100 nM or more (up to 1 muM) increased the [Ca2+]i in a dose-dependent manner. The effect of tri-n-butyltin on the [Ca2+]i was greatly reduced under external Ca2+-free ([Ca2+]o-free) conditions, suggesting its dependence on the presence of [Ca2+]o. Lower trialkyltins, such as triethyltin and trimethyltin at 1 muM, exerted little or no action on the [Ca2+]i. Therefore, the cytotoxic action of tri-n-butyltin may be different from those of lower trialkyltins.