[The fine structure of the rat pineal and the influence of anti-androgens and castroation].

The pineal body, along with the hypothalamus-hypophysis system, is in the centre of sexual hormone regulation and, in addition to other functions, develops an antigonadotropic action through its organ specific hormone (melatonin). In order to clarify further open questions and to analyse more closely the morphology of the fine structure of the organ, light and electron microscopic studies were made of the pineal bodies of sexually mature male rats after hormonal castration by the administration of cyproterone and cyproterone acetate. The findings were compared with results obtained in the pineal bodies of surgically castrated animals of the same strain. Epiphysectomy was performed 3, 6, 9 and 12 weeks after castration or application of antiandrogen. In the pineal bodies, "light" and "dark" pineal cells and an interstitial cell form could be detected electronmicroscopically. The interstitial cells are found localised near the vessels in particular; their ramifications reach into the perivascular cleft. The light pineal cells preponderate and react essentially in the series; they are therefore considered as the really active form of parenchyma cells. Increased cell activity is already observed three weeks after treatment with antiandrogen: the nucleoli are enlarged, the ribosomes, the mitochondria and ergastoplasm are increased, the endoplasmic reticulum quantified and extended, and also the Golgi regions. The cells are consequently enlarged. Lysosomes also appear which frequently enter the liposomes. The changes in the liposomes after application of antiandrogen are remarkable. Initially they are evacuated, partially drawn out. Later the liposomes are enlarged and increased and often fill the cell body. These pineocytes form an appendage to the castration cells of the hypophysis. The liposomes are in a very close spatial, formal genetic relationship to the Golgi apparatus and to the rough walled reticulum. The larger liposomes apparently arise also through the confluence of smaller ones. Three structural elements of the liposomes could be indentifed: a homogenous, a lamellar and a granular component. The fine morphological reactions are most marked after cyproterone acetate. For the first time, bundles of "microtubuli" are described, the significance of which is not yet clear. They probably arise from the endoplasmic reticulum, they are only found after cyproterone acetate and are presumably due to the gestagen component of the cyproterone acetate. These structures have not previously been observed, either in pineal bodies or in other organs. The structures found after antiandrogen are not so outstandingly recognisable after surgical castration. The biological differences of the surgical compared with hormonal castration therefore seem to be reflected in the cell picture of the pineocytes. Consequently, the pineal body, after treatment with antiandrogen, shows cytostructural changes similar to those of increased anabolism...