Prolactin does not affect steroidogenesis in isolated chicken granulosa cells

Hammond, R.W.; Burke, W. H.; Hertelendy, F.

doi:10.1016/0016-6480(82)90028-4

Cited by 12 publications

(5 citation statements)

References 15 publications

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“…Concordantly, we found no differences in gonadotropin receptor or aromatase expression in the small white follicles. PRL can inhibit ovarian steroidogenesis in birds (Camper and Burke, 1977) and in ovaries in vitro (Zadworny et al, 1989; but see Hammond et al, 1982;Hrabia et al, 2004). PRL-inhibited steroidogenesis may occur through reduced aromatase expression, specifically in small white follicles (Tabibzadeh et al, 1995); we did not observe this.…”

Section: Effects On Gonads and Gonadal Gene Expressioncontrasting

confidence: 58%

“…Additionally, oPRL doses used in these studies may have been higher than ours. Physiological doses of oPRL do not always affect ovarian estradiol and progesterone release in vitro (Hammond et al, 1982;Hrabia et al, 2004), suggesting that high doses may be required to inhibit steroidogenesis and affect ovarian gene expression.…”

Section: Effects On Gonads and Gonadal Gene Expressionmentioning

confidence: 99%

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Prolactin maintains parental responses and alters reproductive axis gene expression, but not courtship behaviors, in both sexes of a biparental bird

Farrar

Flores

Viernes

et al. 2021

Preprint

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Prolactin, a hormone involved in vertebrate parental care, is hypothesized to inhibit reproductive hypothalamic-pituitary-gonadal (HPG) axis activity during parenting, thus maintaining investment in the current brood as opposed to new reproductive efforts. While prolactin underlies many parental behaviors in birds, its effects on other reproductive behaviors, such as courtship, remain unstudied. How prolactin affects neuropeptide and hormone receptor expression across the avian HPG axis also remains unknown. To address these questions, we administered ovine prolactin (oPRL) or a vehicle control to both sexes in experienced pairs of the biparental rock dove (Columba livia), after nest removal at the end of incubation. We found that oPRL promoted parental responses to novel chicks and stimulated crop growth compared to controls, consistent with other studies. However, we found that neither courtship behaviors, copulation rates nor pair maintenance differed with oPRL treatment. Across the HPG, we found oPRL had little effect on gene expression in hypothalamic nuclei, but increased expression of FSHB and hypothalamic hormone receptor genes in the pituitary. In the gonads, oPRL increased testes size and gonadotropin receptor expression, but did not affect ovarian state or small white follicle gene expression. However, the oviducts of oPRL-treated females were smaller and had lower estrogen receptor expression compared with controls. Our results highlight that some species, especially those that show multiple brooding, may be able to maintain mating behavior despite elevated prolactin. Thus, mechanisms may exist for prolactin to promote investment in parental care without concurrent inhibition of reproductive function or HPG axis activity.

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Section: Effects On Gonads and Gonadal Gene Expressioncontrasting

confidence: 58%

Section: Effects On Gonads and Gonadal Gene Expressionmentioning

confidence: 99%

Prolactin maintains parental responses and alters reproductive axis gene expression, but not courtship behaviors, in both sexes of a biparental bird

Farrar

Flores

Viernes

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…Also, studies on sheep [33] (McNatty and Land, 1979), mouse [11], humans [32], porcine [63], chicken and domestic hen [52] and turkey [46] suggest that low concentration of prolactin is required for synthesis of progesterone, since high concentration of prolactin decreases progesterone levels by stimulating hydroxysteroid dehydrogenase enzyme, which brings about the catabolism of progesterone [52,64]. Similar observation in birds is not clear but prolactin inhibits granulose cell progesterone at high doses [56] but not at lower, physiological doses [17]. These support our findings that low levels of progesterone as observed in ducks of the control group, which may also be due to the catabolism of progesterone to 5a-dihydroprogesterone or its epimer 5b-dihydroprogesterone.…”

Section: Discussionmentioning

confidence: 68%

Patterns of folliculogenesis in ducks following the administration of a gonadotropin-releasing hormone 1 (GnRH) analogue

Zoheir

Ahmed

2012

Journal of Genetic Engineering and Biotechnology

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The efficacy of synthetic gonadotrophin-releasing hormone (GnRH) analogue in improving the folliculogenesis of ducks has not been established. The aim of the study was to investigate the effect of oral administration of GnRH analogue as luteinizing hormone releasing hormone A 2 (LHRH-A 2 ) on expression of relevant genes, egg production, changes of hormone levels and an ovarian follicle development in ducks. Five hundred ducks at 220 days old were randomly allotted to five groups, where each bird received daily in food 0, 5, 10, 15, or 20 lg LHRH-A 2 for 60 days. In all treated groups, a non-significant increase in the level of GnRH receptor was noticed as compared to the corresponding control. Interestingly, the egg product in the 10 and 15 lg LHRH-A 2 groups was profoundly increased (P < 0.05) if compared to 0 and 5 lg LHRH-A 2 groups or control. A reduction in circulating prolactin (PRL) levels occurs concurrently with an increase in progesterone (P 4 ) and estradiol (E 2 ) particularly in 5, 10 and 15 lg LHRH-A 2 groups. Maximal apoptotic percentage for the granulosa cells was obtained in 20 lg LHRH-A 2 group as compared to control or 5, 10 and 15 lg treatment groups. Finally, these data suggest that the oral administration of 10 and 15 lg LHRH-A 2 may induce ovarian cycle and play vital gonadotrope role during the folliculogenesis process in ducks. This study also demonstrated a need to concentrate further research on the potential effect of GnRH during the early period to improve the reproductive performance.

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“…This result suggests that the photoperiodically induced rise in prolactin is associated not with reproductive development but with the photorefractory phase, perhaps with gonadal regression (Dawson & Goldsmith, 1984;Goldsmith & Nicholls, 1984) or some other correlate such as moulting. There are numerous reports of such anti-gonadal actions of prolactin in birds, the first by Bates et al (1937;but see Stetson, Lewis &Farner, 1973, andHammond, Burke &Hertelendy, 1982). For instance, injections of mammalian prolactin induce anti-gonadal effects in turkeys and quail (Camper & Burke, 1977a, h).…”

Section: Discussionmentioning

confidence: 99%

“…However, the decline in adult plasma LH levels and gonad size occurs approximately four weeks after peak prolactin levels are achieved (Dufty & Wingfield, 1986a, h), results which are difficult to reconcile with an anti-gonadal function for prolactin. Indeed, Hammond et al (1982) found that in another species that produces large numbers of eggs, domestic chickens, prolactin did not block LH-induced steroidogenesis.…”

Section: Discussionmentioning

confidence: 99%

Prolactin secretion in a brood parasite, the brown‐headed cowbird, Molothrus ater

1987

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Blood samples were collected from a free‐living population of male and female brown‐headed cowbirds, Molothrus ater, during the breeding season and plasma levels of prolactin were measured by radioimmunoassay. Prolactin concentrations in both sexes increased significantly in mid to late May; peak levels were reached by June and were maintained throughout June and into July. Prolactin levels in juveniles were significantly lower than in adults but were still elevated. Prolactin has been implicated in parental care in several avian species; however, cowbirds are brood parasites with complete absence of parental behaviour, suggesting that prolactin must function in another capacity in cowbirds, or that cowbirds have developed target tissue insensitivity to this hormone.

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Prolactin does not affect steroidogenesis in isolated chicken granulosa cells

Cited by 12 publications

References 15 publications

Prolactin maintains parental responses and alters reproductive axis gene expression, but not courtship behaviors, in both sexes of a biparental bird

Prolactin maintains parental responses and alters reproductive axis gene expression, but not courtship behaviors, in both sexes of a biparental bird

Patterns of folliculogenesis in ducks following the administration of a gonadotropin-releasing hormone 1 (GnRH) analogue

Prolactin secretion in a brood parasite, the brown‐headed cowbird, Molothrus ater

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