Inhibitory effect of tunicamycin on the adhesivity and aggregation of embryonic brain cells.

Tunicamycin (TM) - (0.1, 1.0 and 10 micrograms/ml) inhibits insignificantly the adhesivity of embryonic mice brain cells during the first 120 min of incubation. The effect is not dose dependent. The concentration of 10 micrograms/ml added at the onset of experiments has a drastic effect during the time period in which cell regeneration, cell movement and formation of aggregates occurs. Up to the 5th day in vitro (DIV), aggregation is completely inhibited and disrupted parts of cells are mostly present in the medium. The concentration of 1 microgram/ml is less effective, and 0.1 microgram/ml is practically without effect. EM analysis shows that tunicamycin (10 micrograms and 1 microgram/ml) diminish the regeneration and integrity of plasmatic membranes, 10 micrograms/ml of tunicamycin destroys cytoplasmatic organelles which is probably the cause of the decline of cellular regeneration and of aggregate formation. Tunicamycin (10 micrograms/ml), if added to the already formed aggregates evokes their disintegration and lower doses (1 microgram/ml) liberated cells from aggregates into the medium.