Influence of somatostatin and epidermal growth factor (EGF) on the proliferation of thyroid follicular cells in organ culture

The aim of the present study has been to examine the effects of various concentrations of somatostatin (SS), epidermal growth factor (EGF), as well as of interactions among SS, EGF and thyrotropin (TSH) in their influence upon the mitotic activity of thyroid follicular cells (TFC) in organ culture. The stathmokinetic method was employed. It was shown that: (1) SS, at the concentration of 10(-7) M, suppressed the mitogenic effect of TSH, as well as of TSH and EGF employed together, on TFC; (2) EGF, at the concentration of 10 and 100 ng/ml, increased the mean mitotic activity rate of TFC; (3) TSH and EGF revealed an additive action on TFC proliferation. The obtained results evidently suggest an antiproliferative effect of SS and mitogenic action of EGF on TFC in organ culture.     

Effect of experimental hyperthyroidism on the elemental content of rat hepatocytes

X-ray microanalysis has been used to determine elemental content in the cytoplasm of hepatocytes of hyperthyroid rats in comparison with euthyroid controls. No significant differences were found for any examined element (sodium, phosphorus, sulfur, chlorine, potassium, magnesium and calcium). In contrast to earlier reports from another laboratory, these data indicate that thyroid hormones do not substantially affect elemental content in rat hepatocytes.