Qualitative and quantitative changes in the hypothalamus and the ependyma of the 3d cerebral ventricle in sheep after irradiation and hormonal stimulation

In the submitted work we concentrated our attention on the study of the changes in neurosecretion. PAS positive mucopolysaccharides in the hypothalamus and ependyma of the IIIrd cerebral ventricle and on studying the changes in the volume of the cell nuclei of the neurons of nucl. supraopticus (NSO), nucl. hypothalamicus centromedialis (NVM) and nucl. tuberomamillaris (NTM) of sheep after irradiation and after hormonal stimulation. We made our observations on 28 sheep of the Slovak Merino breed, of average live weight 35 to 40 kg, two- and three-years old in the period of physiological anoestrum. The first group of four ewes and the second group of four yearling lambs were controls. The third group of six ewes and the fourth group of six yearlings were exposed to irradiation all over with a dosage of 2.46 Gy (250 R) for a period of five days. To synchronize the oestrum of all the sheep we used agelline sponges which we fitted five days before irradiation. After the irradiation and removal of the sponges we gave the test sheep hormonal stimulation with 3 X 500 i. u. of serum gonadotropin. The fifth group of four ewes and the sixth group of four yearlings were only stimulated without irradiation. The fifth day after stimulation we slaughtered the sheep. We processed the brain samples by the usual histological methods. We carried out karyometric analysis with 3000X magnification and the measurement of 200 cells from one sample. We processed the values obtained mathematically according to Fischer and Inke (1956). We evaluated the quantity of neurosecretion material with a light microscope according to Nakahara (1962). We found that the multiplication of neurosecretion and the increased activity of the PAS reaction in the hypothalamic nuclei studied show that the irradiation and hormonal treatment stimulate the function of the hypothalamic structures. The results of the karyometric analysis in the yearlings also confirm this opinion. In the ewes the inhibitive influence of irradiation was probably manifest. The giving of hormones in combination with irradiation causes the multiplication of ependyma cells and the desquamation of surface layers.