Suppression of ovine plasma FSH by bovine follicular fluid: neutralization by plasma from ewes immunized against an inhibin-enriched preparation from bovine follicular fluid

Al-Obaidi, Sabah A.R.; Bindon, B. M.; Hillard, M. A.; O’Shea, Tim; Piper, LR

doi:10.1677/joe.0.1110001

Cited by 10 publications

(3 citation statements)

References 13 publications

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“…It has been known for many years that injection of oestradiol (Salamonsen et al, 1973;Jonas et al, 1973) or crude preparations of 'inhibin' (e.g. bovine follicular fluid) causes a suppression in the concentration of FSH in sheep (Miller et al, 1982;McNeilly, 1984;Al-Obaidi et al, 1986). However, these studies involved the injection of large amounts of hormone and/or crude preparations of inhibin (usually follicular fluid treated with charcoal to remove steroids) and, so their physiological relevance is uncertain.…”

Section: The Effect Of Oestradiol and Inhibin On Fsh Concentrationmentioning

confidence: 99%

Inhibin and oestradiol in the control of FSH secretion in the sheep

Baird

Campbell²,

Mann³

et al. 2019

Proc

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In the sheep both FSH and LH are necessary for development of large antral follicles. The secretion of FSH is controlled by the negative feedback effect of two ovarian hormones, oestradiol and inhibin, acting at the level of the anterior pituitary. Both are derived from the granulosa cells of large antral follicles which are present in sheep ovaries throughout the oestrous cycle. FSH stimulates growth and mitosis and so the fully differentiated granulosa cells of the large preovulatory follicles acquire receptors for LH, have maximal aromatase activity and produce large amounts of inhibin. The number of these large antral follicles (oestrogenic) which have the potential for ovulation corresponds to the ovulation rate specific for each particular breed of sheep. Over 90% of the oestradiol secreted by the ovaries is derived from these chosen follicles. In contrast, inhibin (and androstenedione) is also secreted by large antral follicles which have lost or not yet acquired maximal aromatase activity. The secretion of oestradiol by the preovulatory follicle(s) is dependent on the supply of androgen precursors produced by the theca which is stimulated by LH. When the concentration of progesterone falls at the end of the luteal phase the increased secretion of LH stimulates the progressive increase in secretion of oestradiol which occurs during the follicular phase. At this stage of the cycle there is a modest inconsistent rise in inhibin, the secretion of which is not stimulated by LH but is related to the increase in the number of large antral follicles. It is suggested that inhibin with its long half-life sets the overall level of negative feedback while oestradiol is responsible for the day-today fluctuations in the concentration of FSH which determines the number of ovulatory follicles. This dual control of FSH is adapted to monitor both the total number of large antral follicles in the ovaries (inhibin) and the number which are selected for ovulation (oestradiol).

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Section: The Effect Of Oestradiol and Inhibin On Fsh Concentrationmentioning

confidence: 99%

Inhibin and oestradiol in the control of FSH secretion in the sheep

Baird

Campbell²,

Mann³

et al. 2019

Proc

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“…In contrast, both active (Henderson, Franchimont, Lecomte-Yerna et al 1984;Al-Obaidi, Bindon, Hillard & O'Shea, 1986;Cummins, O'Shea, Al-Obaidi et al 1986;Forage, Brown, Oliver et al 1987;Findlay, Doughton, Robertson & Forage, 1989;Wrathall, McLeod, Glencross et al 1990) and passive (Mann, Campbell, McNeilly & Baird, 1989) immunoneutrali¬ zation of inhibin results in an increase in ovulation rate. In some, but not all, cases, this increase in ovulation rate was related to an increase in the plasma concentration of FSH (see McNeilly et al 1991 for discussion).…”

mentioning

confidence: 95%

Effect of follicular fluid and inhibin immunoneutralization on FSH-induced preovulatory follicle growth in the ewe

McNeilly

Crow²,

Campbell³

1991

Journal of Endocrinology

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The potential direct ovarian effects of immunoneutralization of inhibin, which increases, and follicular fluid treatment, which inhibits, follicle development in normal ewes was investigated in a sheep model in which endogenous FSH and LH secretion was suppressed thus removing any potential effects of treatment-induced alterations in endogenous FSH or LH secretion. Eighteen Welsh Mountain ewes were treated with two agonist implants containing 3.3 mg buserelin giving a total of 6.6 mg buserelin per animal. During week 5 of treatment all ewes were given a 72-h continuous infusion of ovine FSH (5 micrograms/h) starting at 09.00 h. Six ewes were treated with antiserum to the 1-26 alpha peptide fragment of porcine inhibin 0 h and 24 h after the start of the FSH infusion, and a further six ewes were treated with charcoal-stripped ovine follicular fluid (oFF) as a source of inhibin, at 09.00 and 17.00 h throughout the 72 h of FSH infusion. The plasma concentrations of both FSH and LH were significantly reduced in all ewes after 5 weeks of treatment with buserelin, and no large follicles greater than 2.5 mm in diameter were present. Treatment with inhibin antiserum or oFF had no effect, compared with control ewes, on the plasma concentrations of either FSH or LH during the FSH infusion period. After 72 h of FSH infusion there was no difference in the number of small follicles (less than 2.5 mm in diameter) or large follicles (greater than 2.5 mm in diameter) or the size of the largest follicles between control ewes and ewes treated with either inhibin antiserum or oFF.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…The first efforts to study the effects of active immunization against hormones were done with luteinizing hormone (LH) (Wakabayashi and Tamaoki, 1966;Quadri et al, 1966;Pineda et al, 1968). Subsequently, a vast array of protein-, peptide-and steroid hormones have been tried, including follicle-stimulating hormone (FSH) (Torjesen and Sand, 1975;Wickings and Nieschlag, 1980;Al-Obaidi et al, 1986)) human chorionic gonadotrophn (hCG) (Talwar et al, 1976;) thyroid-stimulating hormone (TSH) (Melmed et al, 1980)) inhibin (Henderson et al, 1984;Scanlon et al, 1993)) growth hormone (GH) (Beattie et al, 1992), luteinizing hormone-releasing hormone (LHRH) (Fraser and Gunn, 1973;Ladd et al, 1990;Adams and Adams, 1992;Thau, 1992;Hoskinson et al, 1990)) vasopressin (Kamoi et al, 1977)) somatostatin (Varner et al, 1980)) testosterone (Thomson et al, 1985;Hillier et al, 1973)) progesterone (Kaushansky et al, 1977) and many others (Ohlson et al, 1981;Yamada et al, 1978;Bettencourt et al, 1993;Ronayne et al, 1990;Skinner et al, 1984;Mettler and Czuppon, 1985;Travis, 1993).…”

Section: Active Immunization Against 'Self'mentioning

confidence: 99%

Basic aspects of immunomodulation through active immunization

Meloen¹

1995

Livestock Production Science

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This paper reviews how immunomodulation through active vaccination has evolved in the past 25 years. Although initially it progressed isolated from the main stream of immunological research and vaccine development, lately it merged with this main stream and is taking full advantage of the newest developments in vaccinology. The first immunomodulation vaccine is already on the market, while various others are close to it. Not in the least because one of the major stumbling blocks of immunomodulation through active vaccination, the inherent low immunogenicity of 'self' antigens, has in a number of other cases been solved. Most progress has been made in veterinary applications and has helped to formulate practical rules, necessary to break immunotolerance. It is not unlikely that these rules will be used to design better immunomodulation vaccines to be used in humans; notably to control fertility or combat tumours.

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Suppression of ovine plasma FSH by bovine follicular fluid: neutralization by plasma from ewes immunized against an inhibin-enriched preparation from bovine follicular fluid

Cited by 10 publications

References 13 publications

Inhibin and oestradiol in the control of FSH secretion in the sheep

Inhibin and oestradiol in the control of FSH secretion in the sheep

Effect of follicular fluid and inhibin immunoneutralization on FSH-induced preovulatory follicle growth in the ewe

Basic aspects of immunomodulation through active immunization

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