Corpus luteum hormones

CKs also play a role in leukocyte trafficking during ovarian function. For example, CKs are expressed and leukocytes accumulate within the ovulatory follicle and the corpus luteum. Hormonal and embryonic regulation of CKs are thought to be responsible. 

Butenandt, A. and Westphal, O. (1934) Zur Isolierung und Charakterisierung des Corpus-luteum-Hormones. Berichte der Deutschen Chemischen Gesdlschafi, 67, 1440-1442. 

Progesterone, Pregrt-4-ene-3,20-dione A -preg-nene-3,20-dione corpus luteum hormone luteohormone ... 

Gestogens or corpus luteum hormones are mostly secreted by the corpus luteum portion of the ovary and the metabolized to various inactive products, e.g., pregnanediol. The metabolities are esentially excreted through urine. 

Name aprominent Corpus Luteum Hormone and discuss its synthesis from aglycoside obtained... 

Third, the corpus luteum hormone (HVH-B) content (average value pg/L) in the serum of pregnant women and pregnant mares was 10,000 and 1,000, respectively. The corpus luteum hormone (HVH-B) content (average value pg/L) in the urine of pregnant women and pregnant mares was 10,000 and -(not detected), respectively. 

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. 

The ceUular source of the various ovarian steroids has been difficult to unravel, but a transfer of substrates between two cell types is involved. Theca cells are the source of androstenedione and testosterone. These are converted by the aromatase enzyme in granulosa cells to estrone and estradiol, respectively. Progesterone, a precursor for all steroid hormones, is produced and secreted by the corpus luteum as an end-product hormone because these cells do not contain the enzymes necessary to convert progesterone ro other steroid hormones (Figure 42-8). 

Luteolysis The structural and functional degradation of the corpus luteum that occurs at the end of the luteal phase in the absence of pregnancy caused by the hormones prostaglandin-2(X and oxytocin. Communication between the corpus luteum and uterine endometrium is necessary for luteolysis. 

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.

If fertilisation does not occur, the corpus luteum regresses and the levels of oestrogen and progesterone fall. However, if fertilisation does occur, the corpus luteum is maintained. Regression of the corpus luteum is prevented by the implanting blastocyst which secretes a hormone, human chorionic gonadotrophin (hCG). This occurs about a week after fertilisation. The structure of this hormone is similar to that of LH and it takes on the role of LH in maintenance of the corpus luteum. To do this, it binds to the LH receptor... 

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). 

Progesterone Hormone produced naturally by corpus luteum, adrenals and placenta. Serum half-life is only a few minutes Dysfunctional uterine bleeding. Sustaining pregnancy in threatening abortion... 

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