Livestock Studies 1967, Vol 7, Num, 4     (Pages: 148-159)

The reproductive Hormons


Viewed : 136 - Gonadotrophins and Gonadal hormons were briefly reviewed and some of the main recent developments achieved in this field were given in this study. Gonadotrophins are, principally, classified as Pituitary Gonadotrophin (such as FSH and LH), Human Chorionic Gonadotrophin (HCG) and Pregnant Mare Serum (PMS). These Gonadotrophins are produced or secreted by the anterior pituitary, the Human chorionic villi (by the cells of cytotrophoblast) and, probably, the endometrial cups of pregnant mares respectively. While human chorionic gonadotrophic hormons is found in the urine of pregnant women the PMS gonadotrophin is only found in the blood.

Gonadal hormons, estrogen, progesteron and testesterone are formed and secreted by the folliculs, the corpus luteum and the leydig cells of the testicular interstitial tissue respectively. The phenomenon of ovulation, formation of Graffian follicul and corpus luteum were discussed here in order to disclose the reciprocal relationship occured between pituitary gnodotrophic complex and the gonadal hormons.

The findings in regard of hypothalamic neuro secretion were given by discussing the neuro homoral phenomenon wihich took place between hypothalamus and the pituitary gland. It has been, in fact, shown by the technic of blocking the pituitary stalk that hormon producing materials and hormons which formed in the hypothalamus are transfered through portal and neurel ways to the anterior and posterior pituitary gland.

There are evidences that hormon producing materials reach anterior pituitary via portal was and cause the formation of anterior pituitary gonadotrophin while hormons produced in the hipothalamus, scuh as oxitocin, follow the neural pathe to posterior pituitary and, are being stored there until they are released into blood circulation. Keywords :