Morphology and histochemistry of the "C" cells of guinea pig thyroid gland after treatment with STH preparation: Part II--young animals.

Investigations were carried out on 32 male guinea pigs 2 to 3 months of age. The STH (produced by BIOMED, Warszawa, Poland) was administered intramuscularly every other day, in 7 injections of 20 Evans's units (E. U.) or 100 E. U./kg body weight each. Thyroid gland sections were stained with heamatoxylin and eosin and with the Azan method. The C cells were detected with the modified silver method of Grimelius and with the HCl-toluidine blue and HCl-lead haemotoxylin techniques. Moreover, reactions were performed for succinate and alpha-glycerophosphate dehydrogenases and also for non-specific esterases and non-specific acetylcholinesterase. STH evoked proliferation of the C cells, changed their morphology and activity pattern of the enzymes present therein, probably testifying to an enhanced secretory activity of these cells.