[Histocytological and morphometric studies on the epiphysis cerebri of male Wistar rats following lead poisoning and experimental hypothyroidism].

In a chronic experiment, male white Wistar-rats are treated with methylthriouracil and lead acetate alone and in combination. Additionally the animals of 2 groups are thyroidectomised. The pineal glands are investigated gravimetrically, histologic-cytologically, and caryometrically. The rank correlation analysis of the gravimetrical and caryometrical results proves the significance. The results show a decrease pineal activity following as well methylthiouracil application as thyroidectomy. The strongest decrease of the activity in the combination group thyroidectomy plus lead acetate is obtained. Changes in the pineal glands are not obtained neither after lead acetate application alone nor in combination with methylthiouracil. The results allow to draw the following conclusion: Lead acetate reduced the effect of methylthiouracil, in our opinion a hypothetic methylthiouracil-lead-compound is built. This interpretation is supported by the persistent effect of thyroidectomy whenever lead acetate is combined with thyroidectomy. These results and the results of the suprarenal cortex (Peschke et al. 1981) show clearly, that there is an interference between the methylthiouracil and lead acetate. Under these experimental conditions, one can speak of an ineffectual methylthiouracil-lead-compound.