[Influence of hypothyreodism on the quantitative Karyo- and cytoarchitecture of rat hepatocytes. (A morphometrical and cytophotometrical study on rat hepatocytes 3 weeks after thyreoidectomy) (author's transl)].

INTRODUCTION

Thyroid hormoned influence the quantitative cytoarchitecture of hepatocytes by stimulating the membrane synthesis of mitochondria and ergastoplasm. The cellular and nuclear changes produced by thyroidectomy were analysed cytophotometrically and morphometrically.

MATERIAL AND METHODS

21 days after thyroidectomy the liver tissues of 10 male Wistar rats were examined. 5 sham-operated animals served as controls. All rats received Altromin-R-standard diet. The cytophotometric analysis is based on the method described by Sandritter. The morphometric study was carried out following Weibel's methods.

RESULTS AND DISCUSSION

As a consequence of the changed cellular metabolism, smaller hepatocytes and nuclei (but larger nucleoli) are found in the hypothyroid rats. As compared with controls, hepatocytes hardly show tetraploid nuclei, which is due to inhibited polyploidisation. The mitochondrial content has become considerably smaller in the hypothyroid hepatocytes. The cristal membranes, the mitochondrial and peroxysomal volume per hepatocyte show a similar reaction pattern, which is considered to be a sign of reduced cellular metabolism. The volume loss of the ergastoplasm confirms this assumption.