Growth hormone: a reproductive paracrine/autocrine?

Hull, Kerry; Murphy, Ann; Luna, Maricela; Aramubura, C.; Harvey, Steven

doi:10.1016/s1095-6433(99)90383-5

Cited by 2 publications

(2 citation statements)

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“…GH and IGF-1 are both found to be produced locally in the chicken reproductive tract (), implicating the autocrine or paracrine action of the GH/IGF-1 system, in addition to their endocrine function ( , ). In this study, the abundances of GH-R and IGF-IR mRNA decreased significantly with daidzein treatment, which was contrary to our previous expectation that GH-R and IGF-IR mRNA expressions in shell glands would be up-regulated significantly by daidzein supplement.…”

Section: Discussionmentioning

confidence: 99%

Effect of Dietary Daidzein on Egg Production, Shell Quality, and Gene Expression of ER-α, GH-R, and IGF-IR in Shell Glands of Laying Hens

Zhu

Zhou

et al. 2007

J. Agric. Food Chem.

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Our previous studies demonstrated that dietary daidzein improves egg production in ducks during the late period of the laying cycle. The present study was aimed to investigate the effect of daidzein in laying hens, with more focus on eggshell quality. The expression of ER-alpha, GH-R, and IGF-IR mRNA in shell glands was determined to identify the target genes of daidzein action and to reveal the relationship between shell quality and profiles of gene expression in shell glands of laying hens. 1000 ISA hens, at 445 days of age, were allotted at random to two groups and given the basal diet with or without 10 mg of daidzein per kg diet for 9 weeks. Daidzein supplement significantly increased the egg laying rate and the feed conversion ratio. The eggshell thickness increased, while the percentage of cracked eggs decreased in daidzein-treated hens. Serum E2 and phosphate concentrations were not altered, but the level of serum Ca2+ and the tibia bone mineral density were significantly increased in the daidzein-treated group compared with their control counterparts. In parallel with the significant increase of oviduct weight, significant down-regulation of GH-R and IGF-IR mRNA and a trend of decrease in ERalpha mRNA expression in shell glands were observed in daidzein-treated hens. The results indicate that dietary daidzein improves egg laying performance and eggshell quality during the late (postpeak) laying stage of hens, which is associated with modulations in gene expression in the shell gland.

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Section: Discussionmentioning

confidence: 99%

Effect of Dietary Daidzein on Egg Production, Shell Quality, and Gene Expression of ER-α, GH-R, and IGF-IR in Shell Glands of Laying Hens

Zhu

Zhou

et al. 2007

J. Agric. Food Chem.

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“…These actions may reflect endocrine roles of pituitary GH, directly or via induction of hepatic or local IGF-I, as well as autocrine or paracrine roles of GH produced in reproductive tissues. It may also act by increasing gonadotropin secretion and responsiveness (13,37,38,39).…”

mentioning

confidence: 99%

Desensitization of the JAK2/STAT5 GH signaling pathway associated with increased CIS protein content in liver of pregnant mice

Miquet

Sotelo²,

Bartke³

et al. 2005

American Journal of Physiology-Endocrinology and Metabolism

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(CIS) is considered a major mediator of this desensitization. Pregnancy is accompanied by an increment in GH circulating levels, which were reported to be associated with hepatic GH resistance, although the molecular mechanisms involved in this resistance are not clearly elucidated. We thus evaluated the JAK2/ STAT5b signaling pathway and its regulation by the suppressors of cytokine signaling (SOCS)/CIS family and the JAK2-interacting protein SH2-B␤ in pregnant mouse liver, a model with physiological prolonged exposure to high GH levels. Basal tyrosyl phosphorylation levels of JAK2 and STAT5b in pregnant mice were similar to values obtained for virgin animals, in spite of the important increment of GH they exhibit. Moreover, these signaling mediators were not phosphorylated upon GH stimulation in pregnant mice. A 3.3-fold increase of CIS protein content was found for pregnant mice, whereas the abundance of the other SOCS proteins analyzed and SH2-B␤ did not significantly change compared with virgin animals. The desensitization of the JAK2/STAT5b GH signaling pathway observed in pregnant mice would then be mainly related to increased CIS levels rather than to the other regulatory proteins examined. pregnant mice; growth hormone signaling; growth hormone receptor; suppressors of cytokine signaling/cytokine induced suppressors; signal transducer and activator of transcription

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Growth hormone: a reproductive paracrine/autocrine?

Cited by 2 publications

References 0 publications

Effect of Dietary Daidzein on Egg Production, Shell Quality, and Gene Expression of ER-α, GH-R, and IGF-IR in Shell Glands of Laying Hens

Effect of Dietary Daidzein on Egg Production, Shell Quality, and Gene Expression of ER-α, GH-R, and IGF-IR in Shell Glands of Laying Hens

Desensitization of the JAK2/STAT5 GH signaling pathway associated with increased CIS protein content in liver of pregnant mice

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