Ovulation hormonal control

The concept of hormonal control of ovulation first appeared in 1921 when Ludwig Habedandt, a physiologist at the University of Iimsbmck, showed that extracts of the corpus luteum, containing progesterone [57-83-0] C2 H2q02, could inhibit ovulation and make mice and rabbits infertile (10). Subsequent research showed that this phenomenon occurred in other species as well. 

In grouped female mice ovulation and estrus are suppressed (Champlin, 1971) and pseudopregnancies occur (van der Lee and Boot, 1955). The odor of crowded female mice (eight per cage) inhibited ovulation in other females. The hormonal control of this effect has been difficult to explain. Early studies indicated that ovariectomized mice were not able to inhibit other females but in other studies, ovariectomized females still inhibited estrus in other females (Marchlewska-Koj, 1990). 

Kdn-gp appeared to be synthesized during relatively later stages of oogenesis, since it was undetectable in the oocyte 3 months prior to ovulation. Although the cell types that synthesize Kdn-gp have not been identified, it is most likely synthesized under hormonal control in some extraoocj e cells (i.e. follicle cells), secreted and partly incorporated into the second outermost layer of the vitelline envelope just before ovulation. Kdn-gp may thus be a molecule homologous to the oviduct glycoproteins of mammals that are reported to be secreted and partly incorporated into the egg surface [58-60]. 

Goetz, F. W., 1983, Hormonal control of oocyte final maturation and ovulation in fishes, Fish Physiology, Vol. IXB, Behavior and Fertility Control, W. S. Hoar, D. J. Randall, and E. M. Donaldson, eds.. 

The hormonal control of the estrous cycle and ovulation is similar in eutherian and marsupial mammals (Sutherland et al., 1980). However, in marsupials, gestation is always shorter than the estroUs cycle and pregnancy does not interrupt the cyclic recurrence of estrus (Sharman, 1970). Spontaneous ovulation appears to be the rule in marsupials and the estrous cycle of polyestrous species is approximately one month in length (Tyndale-Biscoe, 1973). The effects of social factors on reproduction in female marsupials have not heretofore been examined systematically, in part because it has been difficult to maintain and breed... 

In breast cancer patients, total PR status is measured for hormonal treatment. The presence of PR is associated with increased survival rates and hormonal responsiveness of mammary tumors. PR agonists are widely used in contraception, HRT, breast cancer, and endometrial hyperplasia. Antiprogestins such as RU486 are used for blocking ovulation and preventing implantation, and in addition they are in clinical testing for the induction of labor and to control various neoplastic transformations. 

Historically, the 1950s represented an important time in the control of human fertility. It was during that decade that the first combined oral contraceptives were developed. Shortly after the discovery that the exogenous administration of hormones such as progesterone successfully blocked ovulation, the use of hormonal steroids quickly became the most popular method of contraception worldwide. Specifically, combined oral contraceptives represent the most commonly used reversible form of contraception today and it is estimated that nearly 100 million women worldwide take oral contraceptives.1 Further, in the United States, it is estimated that at some time during their lives, more than 80% of women born since 1945 have used oral... 

Antibiotic revolution has provided long and healthy life to people. The life expectancy has almost doubled. The increased population has caused many social problems in terms of food resources, environmental issues, employment, etc. To control these problems, population is required to be controlled. This has lead to the concept of family planning. Antifertility drugs are of use in this direction. Birth control pills essentially contain a mixture of S)mthetic estrogen and progesterone derivatives. Both of these compounds are hormones. It is known that progesterone suppresses ovulation. Synthetic progesterone derivatives are more potent than... 

Progesterone ranks with estradiol as one of the key hormones that controls the reproductive cycle in the mammalian female. Progesterone, synthesized by a structure on the ovary that forms immediately after ovulation known as the corpus luteum, inhibits subsequent ovulation until the next cycle. Increased levels of progesterone are essential in... 

Use of Hormones to Alter Normal Endocrine Function. Because of the intrinsic control mechanisms in the endocrine system, administration of exogenous hormones can often affect the normal release of hormones. This fact can be exploited in certain situations to cause a desired change in normal endocrine function. For instance, oral contraceptives containing estrogen and progesterone inhibit ovulation by inhibiting the release of LH and FSH from the anterior pituitary. 

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