Norio Funahashi

Effects of bis (tri-n-butyltin) oxide on endocrine and lymphoid organs of male rats.

A total of 160 Sprague‐Dawley rats averaging in body weight, were used for hlstopathological and biochemical studies of toxicity of bis (tri‐n‐butyltin) oxide (TBTO). Short‐term effects and long‐term effects were examined. LD50 of TBTO by gastric tubing was 197 mg/kg. The effects of a single dose of TBTO were transient, and rapid recovery followed. TBTO at a a single dose of 100 mg/kg, or a total dose of 390 to 780 mg/kg In 13 weeks, or 780 to 1,560 mg/kg in 26 weeks, caused adrenal hypertrophy, flattening of the thyroid epithelium and atrophy of the thymus and lymph nodes. A single or repeated administration induced swelling and vacuolatlon of aldehyde‐fuchsin‐posltive cells in the adenohypophysls. The lmmunohistochemlcal stainability of the cytoplasm of ACTH‐cells was markedly depressed 24 hours after TBTO treatment, and that of the cytoplasm of TSH‐cells was enhanced. Analogous an inverse relationship was also manifested in the hormonal levels of serum: levels of Cortisol were elevated, while those of T‐4 and TSH were depressed.