Regulation of ovarian follicular and luteal function during treatment with exogenous gonadotropins in anovulatory infertility

Yuen, Basil Ho; Sy, Lydia; Cannon, Wendy

doi:10.1016/0002-9378(81)90195-2

Cited by 19 publications

(7 citation statements)

References 17 publications

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“…Concentrations of FSH in serum and FSH to LH ratios were relatively high 1 day before LS + BE (TM) and weaning (CM, CP, TP) and then decreased progressively over time (Figs 1 and 2). This changing pattern of the FSH to LH ratio suggests that an optimal combination of the two gonadotrophins is required to initiate the events leading to oestrus and ovulation in pigs (Shaw & Foxcroft, 1985) as has been observed in women induced to ovulate with human chorionic gonadotrophin (Yuen et al, 1981). Pulsatile patterns of LH also appeared similar for sows in oestrus during lactation and after weaning, as did increases in baseline concentrations of LH.…”

Section: Discussionmentioning

confidence: 60%

Endocrine changes before and after weaning in response to boar exposure and altered suckling in sows

Newton¹,

Stevenson²,

Minton³

et al. 1987

Reproduction

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Eighteen sows (6 primiparous and 12 multiparous) were allotted randomly within parity to two lactational treatments: litter separation (LS; 6 h/day) plus boar exposure (BE; 1 h/day; N = 14) beginning 8 days before weaning (4 weeks) and no LS + no BE (controls; N = 4). Blood was collected from all sows via indwelling venous catheters at 20-min intervals for 5 h on Days -1, 0, 1, 2 and 3 from start of treatment. Control sows and those exposed to LS + BE not exhibiting oestrus during lactation were resampled on Days -1, 0, 1 and 2 from weaning. All 10 multiparous sows receiving LS + BE exhibited oestrus during lactation, whereas none of the 4 primiparous sows exposed to LS + BE or the 2 control multiparous and 2 control primiparous sows exhibited lactational oestrus. Overall concentrations of LH in serum were higher (P less than 0.05) in sows receiving LS + BE than in control sows during lactation, whereas overall FSH was higher (P less than 0.05) in primiparous than multiparous sows. Number and amplitude of pulses of LH were greater (P less than 0.05) for treated primiparous than multiparous sows during lactation. Oestradiol-17 beta increased (P less than 0.05) in sows during LS + BE and was higher (P less than 0.01) in multiparous sows of this group than control multiparous or treated primiparous sows. Preweaning concentrations of cortisol and progesterone in serum were higher (P less than 0.05) in treated than control sows for multiparous and primiparous animals. In sows resampled at weaning, the number of pulses of LH was greater (P less than 0.05) in treated primiparous than in control sows. Postweaning concentrations of FSH in serum were unaffected by preweaning treatments. It was concluded that (1) litter separation and boar exposure increased basal and pulsatile secretion of LH in multiparous and primiparous sows; (2) lack of ovarian follicular development and oestradiol secretion may preclude expression of oestrus in primiparous sows during lactation, despite elevated concentrations of FSH and LH in serum; and (3) if elevated concentrations of cortisol and progesterone inhibit the onset of oestrous cycles, in response to litter separation and boar exposure during lactation, the effect is limited to primiparous sows.

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Section: Discussionmentioning

confidence: 60%

Endocrine changes before and after weaning in response to boar exposure and altered suckling in sows

Newton¹,

Stevenson²,

Minton³

et al. 1987

Reproduction

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“…Nevertheless, a positive correlation was established between the mean FSH:LH ratio and sow group categories for all periods; since there is reason to believe that FSH and LH may operate synergistically to control gonadal activity, this observation may be of considerable physio¬ logical significance. Certainly, FSH:LH ratios were shown to decrease in women 2 days before they were induced to ovulate with hCG at a time when oestradiol was rising (Yuen, Sy & Cannon, 1981). This observation may be due to the differential feedback effects of oestradiol on gonadotrophin secretion.…”

Section: Discussionmentioning

confidence: 99%

Relationships between LH, FSH and prolactin secretion and reproductive activity in the weaned sow

Shaw¹,

Foxcroft²

1985

Reproduction

115

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Blood samples were collected from primiparous sows via indwelling jugular cannulae at 15-min intervals for 12 h before and for 24 h (2 sows) or 48 h (10 sows) after weaning and then every 4 h until behavioural oestrus. Weaning to oestrus intervals ranged from 3 to 10 days and 2 sows showed no signs of oestrus and had not ovulated by Days 11 and 16 after weaning. Prolactin concentrations in plasma decreased significantly (P less than 0.001) and reached basal levels 1-2 h after weaning in all sows whilst plasma progesterone concentrations remained basal until approximately 30 h after the preovulatory LH surge in sows that ovulated. Elevated concentrations of prolactin or progesterone during the post-weaning period were, therefore, not responsible for delayed restoration of cyclicity. Overall, mean LH concentrations rose significantly (P less than 0.001) from 0.22 +/- 0.02 during the 12-h period before weaning to 0.38 +/- 0.03 ng/ml during the 12-h post-weaning period. After weaning, pulsatile and basal LH secretions were markedly increased for sows that showed an early return to oestrus (less than or equal to 4 days) compared with sows showing a longer weaning to oestrus interval but a correlation did not exist between either of these LH characteristics and the time taken to resume cyclicity. Mean LH concentrations before weaning were, however, inversely related (r = -0.649; P less than 0.05) to the weaning to oestrus interval. Overall, mean FSH concentrations rose significantly (P less than 0.001) from 151.1 +/- 6.2 (s.e.m.) ng/ml in the 12-h period immediately before weaning to 187.7 +/- 9.7 ng/ml in the subsequent 12-h period but there was no correlation between FSH concentrations, before or after weaning, and the interval from weaning to oestrus. However, a significant correlation was apparent between ovulation rate and peak concentrations of the rise in FSH after weaning (r = 0.746; P less than 0.05) and overall mean FSH values (r = 0.645; P less than 0.05). It is concluded that both LH and FSH concentrations in peripheral blood rose in response to removal of the suckling stimulus at weanling. The increase in LH pulse frequency associated with weaning was not directly related to the weaning to oestrus interval although a specific pattern of LH secretion was observed in sows showing an early return to oestrus (less than or equal to 4 days).(ABSTRACT TRUNCATED AT 400 WORDS)

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“…Estrogen assays, initially in urine 2 and subsequently in serum or plasma, have been used most extensively for monitoring the ovarian response to stimulation with exogenous gonadotropins. [22][23][24] With the advent of radioimunoassay, measurement of circulating concentrations of estradiol provided a rapid method of evaluating the follicular response to stimulation without the need for collecting 24-hour urine samples. Based on urinary 2 and circulating estrogen assays [22][23][24] it became apparent that ovulation induction with exogenous gonadotropins resulted in higher ovulation rates when estrogen levels were stimulated above the physiological range.…”

Section: Monitoring Of Treatmentmentioning

confidence: 99%

“…[22][23][24] With the advent of radioimunoassay, measurement of circulating concentrations of estradiol provided a rapid method of evaluating the follicular response to stimulation without the need for collecting 24-hour urine samples. Based on urinary 2 and circulating estrogen assays [22][23][24] it became apparent that ovulation induction with exogenous gonadotropins resulted in higher ovulation rates when estrogen levels were stimulated above the physiological range. Subsequently, with the use of ultrasound for visualization of the ovarian follicles, it was also evident that the rate of multiple ovarian follicular development in the natural unstimulated cycle was 5% to 10% versus 80% in gonadotropin-stimulated cycles.…”

Section: Monitoring Of Treatmentmentioning

confidence: 99%

“…25 We have previously found that with an estradiol level between 1000 to 1500 pg/ ml at the time of stopping stimulation with hMG, all cycles resulted in ovulation after the administration of the ovulating dose of hCG. 24 If the follicular sizes on ultrasound do not meet the criteria noted, stimulation may be continued provided estradiol levels do not exceed 2000 pg/ml. If ultrasound criteria are met at lower estradiol levels, the ovulating dose of hCG (Profasi, Serono or Pharmascience or APL Ayerst, Montreal) may be administered.…”

Section: Monitoring Of Treatmentmentioning

confidence: 99%

See 1 more Smart Citation

Induction of Ovulation with Exogenous Gonadotropins in Anovulatory Infertile Women

Yuen¹,

Pride²

1990

Semin Reprod Med

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Regulation of ovarian follicular and luteal function during treatment with exogenous gonadotropins in anovulatory infertility

Cited by 19 publications

References 17 publications

Endocrine changes before and after weaning in response to boar exposure and altered suckling in sows

Endocrine changes before and after weaning in response to boar exposure and altered suckling in sows

Relationships between LH, FSH and prolactin secretion and reproductive activity in the weaned sow

Induction of Ovulation with Exogenous Gonadotropins in Anovulatory Infertile Women

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