Effects of the N-acetylgalactosaminyltransferase inhibitor on cultured cerebral cells.

The inhibitor preparation of the UDP-N-acetylgalactosamine: GM3, N-acetylgalactosaminyltransferase (EC 2.4.1.92) (GalNAc-T) produces effects on the neurons and the glial (astrocytes) cells of the cerebrum in culture. The effect in culture is evidenced by aneuritogenesis, deficiency in the GalNAc-T activity, and decrease in the content of gangliosides, proteins, and lipids. In isolated glial cells the effect is evidenced by cytoplasm vesiculation and premature cessation of proliferation compared with control culture. The pattern of gangliosides in the inhibited culture shows a decrease in the amount of GD1a with respect to GD3; this is compatible with the notion that the effect is due to an inhibitor of the GM2 synthase. The inhibitor effects are reverted when it is eliminated after 24 or 48 hr in the culture medium.