[Ultrastructural changes in the adenohypophysis-thyroid system in chronic poisoning by the herbicide linuron].

Ultrastructural adenohypophysis-thyroid system investigation of Wistar male rats under conditions of chronic poisoning by Linuron herbicide and administration of thymohemin immunomodulator was performed. The release of thyrocyte fragments into the vascular lumen, electron-dense deposits in the area of vascular basal membrane, dilatation of endoplasmic reticulum cisternae as well as inhibition of Golgi complex in thyrocytes are observed in the thyroid exposed to Linuron; in the adenohypophysis under the same conditions swelling and splitting of microvessel basal membrane as well as the increase of biosynthetic and secretory thyrotrophic function can be seen. Thymohemin reduces the degree of degenerative processes in the thyroid gland.