The effect of purified ciguatoxin on mitogen responses of mouse spleen lymphoid cells

Ciguatoxin at 10 micrograms per tube showed a slight suppressive effect on mouse unstimulated spleen lymphoid cells. The same CTX concentration demonstrated a significant effect on mouse lymphoid cells in blastogenesis stimulated by mitogens. The lower levels of CTX (1 and 0.1 microgram) had essentially no effect on the spleen cells with the exception of one experiment. Since the high CTX concentration used was sufficient to kill two twenty gm mice, it is suggested that spleen cells are relatively resistant to CTX. Since the primary effects of CTX in vivo appear to be neurological in nature, to achieve the dose levels to affect the immune system would be extremely lethal for the whole animal.