Abstract
The toxic and the teratogenic action of serotonin and its metabolite, 5-hydroxyindole acetic acid, was studied in the chick embryo. These substances were once injected into the yolk sack of the intact eggs which had been kept in an incubator for 4 days. Creatinine sulfate and physiological saline were employed as the controls. Thereafter further incubation was employed. LD50in 10 days after the injection was estimated to be 0.45 mg/egg for serotonin; while for the rest of the tested substances, their lethal actions were sohat their LD50's could not be calculated. Significantly marked constitutional anomalies as follows were produced with serotonin; edema, hernia of the internal organs, undergrowth, varicosis of the portal vein, twisted vertebra, stiff knee-joint, bent toe, and others. Histological examination, however, gave no particular pathological findings.
Whereas neither 5-hydroxyindole acetic acid, creatinine sulfate nor saline gave significant marcro-or microscopic abnormal findings.
The whole body autoradiography with C14-serotonin showed apparent distribution of radioactivity to the yolk sack, urinary sack, and egg shell and moderate incorporation to the stomach, intestine, kidney and eye.
