Ionophore + Cell Lines with the Action - Potential Na Adrenergic , Cholinergic , and Inactive Human Neuroblastoma

SUMMARY Cultured human neuroblastoma cell lines were assayed for biochemical characteristics of neuronal function. The time course of 22Na@ uptake and inhibition of uptake by tetrodotoxin sup ported this. SK-N-MC had no veratridine-dependent 22Na@ uptake. Tyrosine hydroxylase (EC 1.14.10.), glutamic acid decarboxylase (EC 4.1 .1.15), and acetyicholine contents in neuroblastoma cells were compared to those in brain. LA-N-1 and IMR-32 contained 15 and 5 times as much tyrosine hydroxylase, respectively, whereas LA-N-2 , SK-N-SH , and SK-N-MC contained only 0.5 to 5% of that in brain. Acetyl choline was present in LA-N-2 in 15-to 20-fold greater quantities than in brain; other lines had only 10 to 50% of thatinbrain. None ofthecell lines contained glutamic acid decarboxylase. Thus, continuously propogated human neu roblastoma cell lines may have the action potential Na@ ionophore and may be adrenergic (LA-N-i and IMR-32), cholinergic (LA-N-2), or inactive (SK-N-SH and SK-N-MC). This is the first demonstration of the action potential Na@ ionophore and of acetylcholine production in human neuro blastoma cell lines.