The immunopharmacological effects of a newly synthesized compound in vivo,
TOK-8801 (N-(2-phenylethyl)-3,6,6-trimethyl-5,6-dihydroimidazo[2,1-b]thi azo
le-2- carboxamide), on the anti-SRBC plaque-forming cell (PFC) response and delayed-type
hypersensitivity (DTH) reaction were investigated.
Oral administration of
TOK-8801 (0.1-10 mg/kg) resulted in the suppression of the PFC responses to varying doses of
antigen (5 x 10(6), 2 x 10(7), 1 x 10(8)) in C3H/He strain mice (7 W) which are high responders to SRBC
antigen. On the other hand, the compound augmented the PFC response in aged mice (8-9 months) in which the PFC response was markedly depressed compared with that in young mice. In the experiment of the methylated
human serum albumin-induced DTH reaction,
TOK-8801 augmented the reaction in low responder (C57BL/6) mice by
oral administrations of 0.1-1 mg/kg for 5 days from the sensitization, whereas suppressed the reaction in high responder (ICR) mice. These immunopharmacological actions of
TOK-8801 were compared in dose and activity with those of
lobenzarit and
bucillamine. Thus, these results suggest that
TOK-8801 may act as an immunomodulating agent and would be expected to be a useful agent for
autoimmune diseases such as
rheumatoid arthritis.