Abstract
There has been much discussion in recent literature as to whether the anterior pituitary gland produces one or 2 kinds of hormones which act on the mammalian ovary, and through the ovary on the uterus, vagina and mammary gland, or also directly on the last named organ. Zondek 1 and others hold that there are 2 types of anterior pituitary hormones acting on the ovary, (1) the follicular growth hormone, responsible for the growth of follicles and (2) the luteinizing hormone causing the production of corpora lutea and of lutein tissue in general.
As previously indicated, the facts which we have established as well as other facts only partly published can be explained most satisfactorily if we assume that there are at least 2 types of anterior pituitary hormones which act on the ovary, one of which affects also the thyroid gland. These 2 hormones are as follows: (1) A hormone (1) which is responsible for the increase in size of the ovarian follicles and for the maturation processes which take place in the granulosa of follicles. This hormone counteracts the tendency of the granulosa to undergo degeneration, leads to the maturation of the granulosa primarily of the large sized follicles, but may also cause beginning or further advanced maturation of the granulosa of medium-sized and even smaller follicles. If no inhibiting mechanisms are at work, the production of large mature follicles leads in due time to ovulation and to the formation of true corpora lutea with the consequences which follow from the functioning of these organs. However, in many other cases, the large-sized mature follicles do not give rise to ovulation, but an ingrowth of capillaries and of connective tissue cells from the theca interna into the granulosa of such follicles; this is followed by the transformation of the granulosa cells into lutein cells and is usually also accompanied by an increase in the size of the theca interna cells.
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