Effect of Impairment of Thyroid Functions on Intracranial Bone Tumours in AkR Mice

Abstract

Thymectomized AkR mice were treated with ¹³¹I, thyroxin and thiourea. No direct relationship were found between thyroid function disturbances and the frequency of intracranial bone tumours. Mice with induced thyrotoxicosis (0.1 mg of thyroxin/day/mouse) and radiothyroidectomited mice (30 µC_i of ¹³¹I) presented the same frequency of osteomas as the controls. Administration of thiourea (0.5 g/kg mouse/day) increased very significantly the frequency of the tumours. The possibility that this effect of thiourea administration arises, not from its inhibitory effect towards the synthesis of thyroxin, but from hypothalamic lesions is discussed.

Effect of Thiourea on Intracranial Bone Tumour Formation in AkR Mice

“…A study on the effect of impairment of thyroid functions in AkR mice (6) showed that administration of thiourea brought about an increase in intracranial bone tumour (IBT) frequency but partial radiothyroidectomy was without significant effects. These results may suggest that thiourea can directly disturb the functions of the hypothalamo-pituitary pathway and increase the IBT frequency secondarily to this general imbalance.…”