Characterization of the FSH-Suppressing Activity in Follicular Fluid

Rr, Grady; Mc, Charlesworth; Nb, Schwartz

doi:10.1016/b978-0-12-571138-8.50015-9

Cited by 40 publications

(16 citation statements)

References 75 publications

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“…The function of inhibin in the control of FSH secretion suggests that it is an important component of the many hormones that control the mammalian reproductive cycle. In agreement with this idea, roles suggested for inhibin in the rat include maintenance of an appropriate FSH/LH ratio, triggering of the secondary surge of FSH in late proestrus, and control of folliculogenesis (28). These (31) reported the structures of cDNAs encoding the precursors to both porcine inhibin subunits.…”

Section: Kda)mentioning

confidence: 70%

Inhibin A-subunit cDNAs from porcine ovary and human placenta.

Mayo¹,

Cerelli²,

Spiess³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

203

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Inhibin, a gonadal protein that preferentially suppresses the secretion of pituitary follicle-stimulating hormone, has been isolated from porcine follicular fluid and characterized as a 32-kDa protein composed of 18-kDa and 14-kDa subunits. In the present work, oligonucleotide probes predicted from amino-terminal inhibin amino acid sequences have been used to isolate, from a porcine ovarian Xgtll cDNA library, clones encoding the 18-kDa subunit, or A chain, of inhibin. DNA sequence analysis showed that the inhibin A chain is initially synthesized as a larger precursor protein and is predicted to be a glycopeptide. Inhibin A-chain mRNA is present specifically in the gonads, and its synthesis can be induced by treatment of the animal with gonadotropins. The porcine probe was used to isolate a human inhibin A-subunit cDNA from a placental cDNA library. The human precursor is highly homologous to its porcine counterpart and is predicted to generate an 18-kDa glycosylated inhibin A subunit.The biological basis for gonadal regulation of pituitary function was formulated in 1923 by Mottram and Cramer (1), who observed hypertrophy of rat pituitary cells following radiation-induced testicular damage. In 1932 McCullaugh (2) demonstrated that the appearance of these hypertrophied cells could be inhibited by the injection of a water-soluble substance derived from bovine testes, and he termed this substance inhibin. Following the discovery of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), the two pituitary hormones known to regulate the development and activity of the gonads, Klinefelter et al. (3) postulated that a testicular factor, inhibin, exerted a specific negative feedback action on pituitary FSH secretion. This hypothesis was substantiated when numerous investigators demonstrated a direct suppression of peripheral FSH in animals treated with steroid-free testicular or ovarian preparations (4-6).

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Section: Kda)mentioning

confidence: 70%

Inhibin A-subunit cDNAs from porcine ovary and human placenta.

Mayo¹,

Cerelli²,

Spiess³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

203

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“…Patterns of LH and FSH also differ early in the luteal phase, when there is a second increase in plasma FSH but there is no concomitant rise in LH (Dobson, 1978;Roche & Ireland, 1981;. There is evidence that a similar secondary 'surge' in FSH is important for development of follicles for the next ovulatory cycle in rats (Grady et al, 1982). The magnitude of the secondary FSH surge was higher in sheep of the prolific Romanov breed than in less prolific Ile-de-France ewes (Cahill et al, 1981), suggesting that concentrations of FSH early in the oestrous cycle might be related to later growth of follicles.…”

Section: Introductionmentioning

confidence: 99%

Suppression of the secondary FSH surge with bovine follicular fluid is associated with delayed ovarian follicular development in heifers

1990

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Summary. Holstein heifers were given 5 injections (twice/day) of 10 ml charcoalextracted bovine follicular fluid (bFF; N = 6) or 10 ml saline (N = 5) beginning 12 h after the onset of oestrus. Blood samples were collected for determination of plasma concentrations of FSH, LH, progesterone and oestradiol-17\s=b\. Treatment with bFF suppressed the secondary FSH surge (P < 0\m=.\01). Cessation of bFF injections was followed by a rebound period during which FSH was elevated compared with controls (P < 0\m=.\01).Daily ultrasonographic examinations revealed that follicular growth occurred in waves, with 4 of 5 control heifers exhibiting 3 waves and the other 2 waves.In contrast, 5 of 6 bFF-treated animals exhibited 2 waves and the other 3 waves.Appearance of follicles in the first wave was delayed in bFF-treated heifers (Day 3\m=.\3\ m=+-\ 0\m=.\3 compared with Day 1\m=.\4\ m=+-\ 0\m=.\2; P < 0\m=.\0001) and appearance of the dominant follicle of the first wave was delayed (Day 4\ m=. \ 5\ m=+-\ 0\ m=. \ 3compared with Day 1\ m=. \ 8\ m=+-\ 0\ m=. \ 2; P < 0\m=.\0001). Follicles in the second wave appeared later in animals treated with bFF (Day 12\m=.\7\ m=+-\ 0\m=.\4compared with Day 10\m=.\4\ m=+-\ 0\m=.\6; P < 0\m=.\01), and the dominant follicle of this wave also appeared later (Day 13\m=.\0\ m=+-\ 0\m=.\5compared with Day 10\m=.\6\ m=+-\ 0\ m=. \ 5; P < 0\m=.\01).Oestradiol-17\s=b\ increased during the early luteal phase, but this increase occurred later in heifers treated with bFF (peak concentrations on Day 6\m=.\3\ m=+-\0\m=.\6 compared with Day 4\m=.\2\ m=+-\0\m=.\2;P < 0\m=.\05).LH, progesterone and cycle length were not affected by bFF. Delayed follicular growth associated with suppression of FSH suggests that the secondary FSH surge is important in the initiation of follicular development early in the bovine oestrous cycle, and thus may play a role in the regulation of ovarian follicular dynamics.

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“…Much is known about the regulation of secretion of FSH including its stimulation by LH-releasing hormone (LHRH) (2), and its inhibition by sex steroid hormones (3)(4)(5) and inhibin (6)(7)(8)(9). Little is known, however, about the regulation of the biosynthesis of the subunits of FSH at the pretranslational level.…”

Section: Introductionmentioning

confidence: 99%

Sex steroid hormone regulation of follicle-stimulating hormone subunit messenger ribonucleic acid (mRNA) levels in the rat.

Gharib¹,

Wierman²,

Badger³

et al. 1987

J. Clin. Invest.

124

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Follicle-stimulating hormone (FSH) , luteinizing hormone (LH) fl, and a subunit messenger RNA (mRNA) levels were examined in rats after castration and sex-steroid replacement. Subunit mRNAs were determined by blot hybridization using rat FSH$ genomic DNA, and a and LH# complementary DNA (cDNA).Rat FSHI3 mRNA is 1.7 kilobase in size. After ovariectomy, female FSHj6 mRNA levels increased fourfold, whereas those of LH46 and a increased twenty-and eightfold, respectively. With estradiol, all subunits returned toward normal levels. Male LH,8 and a mRNA levels rose eight-and fourfold, respectively, 40 d postcastration, but FSH# mRNA levels increased minimally.After 7 d of testosterone propionate, LH8 and a mRNAs declined to normal levels, whereas FSHti mRNA increased slightly. We conclude that in female rats FSHfi is negatively regulated by gonadal steroids, but to a lesser extent than LH# or a mRNAs, and there is a differential regulation of FSH,6 mRNA levels in males as compared with females at the time points examined.

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Characterization of the FSH-Suppressing Activity in Follicular Fluid

Cited by 40 publications

References 75 publications

Inhibin A-subunit cDNAs from porcine ovary and human placenta.

Inhibin A-subunit cDNAs from porcine ovary and human placenta.

Suppression of the secondary FSH surge with bovine follicular fluid is associated with delayed ovarian follicular development in heifers

Sex steroid hormone regulation of follicle-stimulating hormone subunit messenger ribonucleic acid (mRNA) levels in the rat.

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