Follicle-stimulating effect

The follicle-stimulating effect (FSH = follicle-stimulating hormone), which promotes the development of the follicles in the ovary and the germinal cells of the... 

Bronson F. and Maruniak J.A. (1976). Differential effects of male stimuli on follicle stimulating hormone, luteinising hormone and prolactin secretion in prepubertal female mice. Endocrinology 98, 1101-1108. 

The gonadotropins, follicle-stimulating hormone and luteinizing hormone, exert their effects on the gonads (ovaries in the female and testes in the male). Taken together, the gonadotropins stimulate the gonads to ... 

The gonadotrophic hormones of the pituitary include the interstitial cell stimulating hormone (ICSH), which is present and effective in both males and females, and the follicle stimulating hormone (FSH), which stimulates the development of multiple follicles in females and apparently in males induces spermatogenesis. 

Plasma prolactin levels are reduced with acute treatment and remain suppressed after 28 days of chronic treatment (Murphy et al. 1998). With acute treatment, no effects are seen on plasma luteinizing hormone or testosterone levels. However, chronic dietary 5% ginseng increases testosterone levels in male rats (Fahim et al. 1982). Chronic ginsenosides do not alter posterior pituitary hormones oxytocin and vasopressin (Zierer 1991). Similarly, human males administered ginseng extract showed an increase in plasma testosterone, dihydrotestosterone, follicle-stimulating hormone, and luteinizing hormone, but a decrease in prolactin (Salvati et al. 1996). 

Figure 19.11 Hormones secreted by the hypothalamus, anterior pituitary, ovary and testis and feedback regulation. GnRH is gonadotrophin-releasing hormone the gonadotrophins are follicle-stimulating hormone (FSH) and luteinising hormone (LH). The effect of these hormones on activities in the ovary and testes is shown. FSH stimulates synthesis and secretion of oestradiol from follicle, and spermatogenesis in testis. LH stimulates synthesis and secretion of progesterone from corpus luteum and synthesis and secretion of testosterone by the Leydig cells.

Estradiol subsequently builds up in the blood and first (within 2 to 12 hours) reduces the levels of follicle-stimulating hormone (FSH) and the amplitude of LH pulses, then (within 12 to 48 hours) causes preovulatory surges of LH and FSH. The former promotes ovulation and development of a corpus luteum (reviewed in Martin et ah, 1986). Two compounds have been indicated in the effect of the odor of ram s fleece on LH secretion in anestrous ewes. These are 1,2-hexadecanediol and 1,2-octadecanediol. In Merino sheep at least, maximum stimulation of ovulation requires full exposure to a ram, such as fenceline contact in pastures. Olfactory cues from the ram s wool, presented in a facemask for the ewe, are ineffective by themselves visual and tactile stimuli are also important. The Merino breed does not rely as much on olfactory cues as other breeds of sheep (Pearce and Oldham, 1988). The effect is not necessarily species specific hair extract from male goats stimulates LH release in ewes. For this effect, the accessory olfactory system is not necessary (Signoret etah, 1989). 

Mechanism of Action A testosterone derivative that suppresses the pituitary-ovarian axis by inhibiting the output of pituitary gonadotropins. Causes atrophy of both normal and ectopic endometrial tissue in endometriosis. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are depressed in fibrocystic breast disease. Inhibits steroid synthesis and binding of steroids to their receptors in breast tissues. Increases serum levels of esterase inhibitor. Therapeutic Effect Produces anovulation and amenorrhea, reduces the production of est rogen, corrects biochemical deficiency as seen in hereditary angioedema. 

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