Inhibition of ovulation and LH secretion in the gilt after treatment with ACTH or hydrocortisone

Barb, C. R.; Kraeling, Robert R.; Rampacek, George B.; Fonda, Edward S.; Kiser, T. E.

doi:10.1530/jrf.0.0640085

Cited by 105 publications

(66 citation statements)

References 13 publications

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“…The present study shows that this effect also operates in the female pig and may explain why elevations in plasma cortisol can depress the preovulatory surge of LH in mature gilts (Barb et al, 1982) and why ACTH suppresses the increase in LH in prepubertal gilts after ovariectomy only when the adrenal glands are present (Fonda et al, 1984). Liptrap & Raeside (1983) reported that short-term cortisol infusions enhanced the pituitary responsiveness of mature boars to exogenous GnRH.…”

Section: Resultssupporting

confidence: 53%

Effect of short-term elevations in plasma cortisol concentration on LH secretion in prepubertal gilts

Pearce

Paterson²,

Hughes³

1988

Reproduction

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Summary. Prepubertal gilts were fitted with jugular vein and carotid artery catheters at 148 days of age. At 160 days of age the 24 gilts were allocated to treatment in a 2 \m=x\2 factorial design involving intra-carotid infusion of cortisol (10 mg in 40 ml saline) or saline alone with or without i.v. injection of 5 \g=m\g synthetic GnRH midway through the 1 h infusion. Plasma cortisol concentrations were elevated in gilts infused with cortisol (P < 0\m=.\05). The LH response to exogenous GnRH was reduced by cortisol infusion. Treated gilts released less LH (P < 0\m=.\001) and had a lower mean LH peak (P < 0\m=.\01) than did control gilts but the timing of the induced LH peak was not affected. In the absence of an exogenous GnRH challenge, cortisol infusion increased the endogenous secretion of LH (P < 0\m=.\01). These results suggest that acute elevations in plasma cortisol concentration may be involved in mediating changes in pituitary responsiveness and the secretion of LH in the peripubertal gilt.

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Section: Resultssupporting

confidence: 53%

Effect of short-term elevations in plasma cortisol concentration on LH secretion in prepubertal gilts

Pearce

Paterson²,

Hughes³

1988

Reproduction

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“…At least 1 week after the placement of i.c.v. cannula, and 24 h prior to treatment, all animals were fitted with indwelling jugular catheters (Barb et al 1982). Animals were randomly assigned to one of three groups.…”

Section: Methodsmentioning

confidence: 99%

Central and peripheral administration of kisspeptin activates gonadotropin but not somatotropin secretion in prepubertal gilts

Lents

Heidorn²,

Barb³

et al. 2008

Reproduction

106

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It is well established that kisspeptin signaling is necessary for the onset of puberty in laboratory animals. However, the role that kisspeptin may have in regulating puberty in large domestic animals is unknown. We tested the hypothesis that either central or peripheral infusion of kisspeptin would stimulate gonadotropin and GH secretion in prepubertal gilts. In experiment 1, prepubertal gilts were fitted with i.c.v. cannula and indwelling jugular catheters. Animals were randomly assigned to receive 0, 10, or 100 mg kisspeptin in saline. In experiment 2, prepubertal gilts, fitted with indwelling jugular catheters, randomly received 0, 1, 2.5, or 5 mg kisspeptin in saline intravenously. Serial blood samples were collected every 15 min for 3 h before and 5 h after infusions, and serum concentrations of LH, FSH, and GH were determined. Mean concentrations of LH and FSH remained at basal levels for control animals but were increased (P!0.001) for animals receiving i.c.v. infusion of kisspeptin. Area under the LH and FSH curves following i.c.v. infusion of kisspeptin increased (P!0.001) in a dose-dependent manner. Concentrations of GH were unaffected by i.c.v. treatment. Peripheral administration of kisspeptin increased (P!0.05) serum concentrations of LH but not FSH or GH. Thus, kisspeptin can activate gonadotropic but not somatotropic hormone secretion in prepubertal gilts. The present data support the concept that kisspeptin plays a role in the mechanism involved in initiating puberty in swine.

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“…Pigs were fed to appetite daily, at 0800 and 1700 h, a corn-soybean meal ration (14% crude protein) supplemented with vitamins and minerals, according to the National Research Council guidelines (NRC, 1998). At 1 week after the last ICV surgery, and 24 h before treatment, all pigs were fitted with an indwelling jugular vein cannula (Barb et al, 1982). On the day of the EXP, pigs were fed at 0700 h and blood sampling started at 0800 h. Blood samples were collected every 15 min from 5 h before to 4 h after ICV injections of 150 ml 0.9% saline (S; n 5 4), 25 mg (n 5 4) or 75 mg (n 5 4) of recombinant IGF-I (GroPrep, Adelaide, Australia) in 150 ml of S. Serum was harvested and stored at 2208C until assayed for GH and LH by radioimmunoassay (RIA).…”

Section: Experiments (Exp I)mentioning

confidence: 99%

Insulin-like growth factor-I feedback regulation of growth hormone and luteinizing hormone secretion in the pig: evidence for a pituitary site of action

Barb

Hausman

2009

Animal

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Three experiments (EXP) were conducted to determine the role of insulin-like growth factor-I (IGF-I) in the control of growth hormone (GH) and LH secretion. In EXP I, prepuberal gilts, 65 ± 6 kg body weight and 140 days of age received intracerebroventricular (ICV) injections of saline (n = 4), 25 μg (n = 4) or 75 μg (n = 4) IGF-I and jugular blood samples were collected. In EXP II, anterior pituitary cells in culture collected from 150-day-old prepuberal gilts (n = 6) were challenged with 0.1, 10 or 1000 nM [Ala15]-h growth hormone-releasing hormone-(1-29)NH2 (GHRH), or 0.01, 0.1, 1, 10, 30 nM IGF-I individually or in combinations with 1000 nM GHRH. Secreted GH was measured at 4 and 24 h after treatment. In EXP III, anterior pituitary cells in culture collected from 150-day-old barrows (n = 5) were challenged with 10, 100 or 1000 nM gonadotropin-releasing hormone (GnRH) or 0.01, 0.1, 1, 10, 30 nM IGF-I individually or in combinations with 100 nM GnRH. Secreted LH was measured at 4 h after treatment. In EXP I, serum GH and LH concentrations were unaffected by ICV IGF-I treatment. In EXP II, relative to control all doses of GHRH increased (P < 0.01) GH secretion. Only 1, 10, 30 nM IGF-I enhanced (P < 0.02) basal GH secretion at 4 h, whereas by 24 h all doses except for 30 nM IGF-I suppressed (P < 0.02) basal GH secretion compared to control wells. All doses of IGF-I in combination with 1000 nM GHRH increased (P < 0.04) the GH response to GHRH compared to GHRH alone at 4 h, whereas by 24 h all doses of IGF-I suppressed (P < 0.04) the GH response to GHRH. In EXP III, all doses of IGF-I increased (P < 0.01) basal LH levels while the LH response to GnRH was unaffected by IGF-I (P > 0.1). In conclusion, under these experimental conditions the results suggest that the pituitary is the putative site for IGF-I modulation of GH and LH secretion. Further examination of the role of IGF-I on GH and LH secretion is needed to understand the inhibitory and stimulatory action of IGF-I on GH and LH secretion.

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Inhibition of ovulation and LH secretion in the gilt after treatment with ACTH or hydrocortisone

Cited by 105 publications

References 13 publications

Effect of short-term elevations in plasma cortisol concentration on LH secretion in prepubertal gilts

Effect of short-term elevations in plasma cortisol concentration on LH secretion in prepubertal gilts

Central and peripheral administration of kisspeptin activates gonadotropin but not somatotropin secretion in prepubertal gilts

Insulin-like growth factor-I feedback regulation of growth hormone and luteinizing hormone secretion in the pig: evidence for a pituitary site of action

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