Metabolic fate and mechanism of action of chloroethylthiamine. VI. Mechanism of anticoccidial action of chloroethylthiamine.

Chloroethylthiamine (I) is a new strong coccidiostat against a coccidium, Eimeria ten ella, which is parasitic on the chick cecum (1). Chloroethylthiamine is administered to chicks as a feed additive in a concentration of 0.004 to 0.125%, usually as naphthalene-1, 5-disulfonate salt which is stable and hardly soluble in water. The present series of investigation have been carried out to determine the fate of chloroethylthiamine in chicks after oral admi nistration and to study the mode of action as an anticoccidiostat. In the present paper, the absorption of chloroethylthiamine from chick intestine was studied by means of ligated loop technique and active transport of thiamine and a competitive inhibition on the transport by chloroethylthiamine were elucidated.