[The compensatory-adaptive reactions of the thyroid and adrenal adrenergic structures in the postnatal ontogeny of sympathectomized rats].

The study was performed in albino rats treated during first two postnatal weeks with guanetidin isotonic solution injected subcutaneously in dose 20 mg/kg body weight to obtain desympathization. Control animals received similar volume of the solution during equal terms. Thyroid and adrenal glands were studied in 1- and 6-month-old rats both by light and electron microscopes. Serotonin and catecholamines were revealed by fluorescent-histochemical method. In experimental 1-month-old animals morphological indexes indicate the thyroid gland hyperfunction. In these animals serotonin and catecholamines content is lower in parafollicular endocrinocytes, mast cells and in adrenergic fibres, the density of which is significantly lower than that in control animals. The adrenal gland weight in experimental animals increases due to the medulla. Serotonin and catecholamine content is essentially higher. Thyroid gland in 6-month-old experimental rats is hyperfunctioning. Adrenal fibres density in its stroma is close to control indexes. Catecholamines and serotonin adrenal glands medulla grows with age and remains higher than the appropriate control level, which indicates active participation of adrenal glands in adaptive reactions is desympathized animals. Serotonin plays an important role in local regulation of thyroid glands. Parafollicular endocrinocytes perform the function of local biogenic amines-producers, while mast cells regulate the serotonin content.