Oral administration of serotonin against spinal deformity of chum salmon fry induced by tryptophan deficiency.

In order to elucidate the mechanism for the occurrence of scoliosis as tryptophan deficiency symptom noted only in salmonids so far; tryptophan deficient diet with serotonin which is a trypto-phan metabolite and one of the brain neurotransmitters in mammals, was fed to chum salmon fry and checked for the incidence of scoliotic fish. We did not succeed both in complete prevention of the occurrence and in the restoration to normal fish by the oral administration of serotonin creatinine sulfate (25-300mg/100g diet), but the incidence of scoliosis was apparently lowered by the above treatment. In addition, a few spinal deformity was observed in the fish fed the tryptophan sufficient diet supplemented with p-chlorophenylalanine (29mg/100g diet) which is a depleter of serotonln in vivo.