Ovarian function

Choudhury C, Ray AK, Bhattacharya S, et al. 1993. Non lethal concentrations of pesticide impair ovarian function in the freshwater perch, Anabas testudineus. Environ Biol Fishes 36 319-324. 

Vandenbergh J.G. (1989). Coordination of chemical signals and ovarian function during sexual development. J Anim Sci 67, 1841-1847. 

Physiologic causes Adolescence Perimenopause Immaturity of the hypothalamic-pituitary-ovarian axis no LH surge Declining ovarian function... 

Fauser, B. and Vanheusden, A. 1997. Manipulation of human ovarian function-physiological concepts and clinical consequences. Endocrine Reviews 18(1), 71-106. 

As women age, circulating FSH progressively rises and ovarian inhibin declines. When ovarian function has ceased, serum FSH concentrations are greater than 40 international units/L. Menopause is characterized by a 10- to 15-fold increase in circulating FSH concentrations compared with concentrations of FSH in the follicular phase, a four- to fivefold increase in luteinizing hormone, and a greater than 90% decrease in circulating estradiol concentrations. 

The diagnosis of menopause should include a comprehensive medical history and physical examination, complete blood count, and measurement of serum FSH. When ovarian function has ceased, serum FSH concentrations exceed 40 international units/L. Altered thyroid function and pregnancy must be excluded. 

The effects of raloxifene in premenopausal women have been analyzed in subjects with normal ovarian function treated with high doses (100 to 400 mg daily) at either different time points of their menstrual cycle or continuously for 4 weeks (Baker et al. 1998). Raloxifene did not prevent ovulation, nor did it alter the length of the menstrual cycle or the day of the LH surge. However, it did stimulate FSH secretion, increase serum estradiol levels, and decrease serum PRL. These results are also similar to those reported for premenopausal women taking tamoxifen (Jordan et al. 1991) and are indicative of some antiestrogenic action at either the hypothalamic and/or pituitary level. 

Cooper R, Chadwick R, Rehnberg G, Goldman J (1989) Effect of lindane on hormonal control of reproductive function in the female rat. Tox Appl Pharm 99 384-394 Cooper RL, Stoker TE, Goldman JM, Parrish MB, Tyrey L (1996) Effect of atrazine on ovarian function in the rat. Reprod Toxicol 10 257-264... 

Most goats in the northern hemisphere breed in fall and winter. Decreasing day length stimulates ovarian cycles. In addition to photoperiod, male pheromones stimulate pulse frequency of LH in the blood plasma of females (Martin etal., 1986). This not only enhances the seasonal onset of ovarian function, but also synchronizes breeding and subsequent lambing. 

Strier, K. B. and Ziegler, T. E. (1994). Insights into ovarian function in wild Muriqui monkeys [Muriquiarachnoides). American Journal ofPrimatology 31,31-40. 

B2. Barnard, G., and Kohen, E., Monitoring ovarian function by the simultaneous time-resolved fluorescence immunoassay of two urinary steroid metabolites. Clin. Chem. 44,1520-1528 (1998). 

Danazol is an isoxazole derivative of 17alpha-ethinyl testosterone. It has weak androgenic activity. It inhibits gonadotrophin secretion and is used to suppress ovarian function. It induces endometrial atrophy and has found its major use in the management of endometriosis. Gestrinon has the same indication and acts via a similar mechanism. Danazol has also been used in the management of benign breast disorders such as fibrocystic disease. 

One in four postmenopausal women have osteoporosis. Osteoporosis, a decrease in bone mass, constitutes the most serious effect of menopause. It has been estimated that following cessation of ovarian function, the loss of bone mass proceeds at a rate of 2 to 5% per year. As a result of osteoporosis, as many as 50% of women develop spinal compression fractures by age 75, and 20% will have hip fractures by age 90. 

Ovarian function usually returns within 60-90 days after discontinuation... 

Mechanism of Action A fat-soluble vitamin that may act as a cofactor in biochemical reactions. Therapeutic Effect Is essential for normal function of retina, visual adaptation to darkness, bone growth, and testicular and ovarian function preserves integrity of epithelial cells. 

It inhibits gonadotrophin secretion from pituitary in both men and women thus inhibiting both testicular/ovarian function. 

Its a nonsteroidal estrogen antagonist, which acts by preventing implantation due to embryouterine asynchrony, accelerated tubal transport and suppression of decidualization. It has no effect on pituitary or ovarian functions. It is taken 30 mg twice weekly for 12 weeks followed by once a week as long as fertility is to be suppressed. 

Chronic use of combination agents depresses ovarian function. Follicular development is minimal, and corpora lutea, larger follicles, stromal edema, and other morphologic features normally seen in ovulating women are absent. The ovaries usually become smaller even when enlarged before therapy. 

GnRH and its analogs (nafarelin, buserelin, etc) have become important in both stimulating and inhibiting ovarian function. They are discussed in Chapter 37. 

Neuroendocrine regulation of ovarian function and reproductive cycling... 

The events of the estrous cycle can be used as an indicator of reproductive neuroendocrine and ovarian function in the non-pregnant female. Hormonal, histological and morphological measurements can also be interpreted relative to stage of the cycle and can be used to... 

Ovarian function can be assessed hormonally in humans and experimental animals with in vivo and in vitro techniques. In animals,... 

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