Socha J K, Sechman A, Mika M, Hrabia A
Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Krakow, Poland.
Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Krakow, Poland.
Domest Anim Endocrinol. 2017 Oct;61:1-10. doi: 10.1016/j.domaniend.2017.05.001. Epub 2017 May 8.
This study was undertaken to examine the effect of growth hormone (GH) treatment during pause in laying on (1) the concentration of steroids in blood plasma and oviduct tissues, (2) the expression of mRNA of steroid receptors, and (3) the mRNA expression of selected egg-specific proteins in the chicken oviduct. A pause in egg laying was induced by food deprivation for 5 d, followed by feeding every other day, and then feeding daily from Day 10 onward. Birds were divided into three groups: control (n = 18) fed ad libitum, subjected to pause in laying (n = 18), and subjected to pause in laying and injected every day with 200 μg/kg BW of chicken GH (chGH; n = 18). The oviduct was isolated from hens of each group on Days 6 (when the oviduct was regressed), 13 (during oviduct recrudescence), and 17 or 20 (rejuvenated oviduct) of the experiment. Fasting caused a decrease in plasma concentrations of progesterone (P4), testosterone, and estradiol on Day 6 and a reduction in tissue concentrations of these steroids on Days 6 and 13. Fasting also caused an increased relative expression of estrogen receptor α and β (ERα, ERβ) and progesterone receptor (PR) in the magnum and shell gland on Day 6, increased ERα and PR in the magnum on Days 13 and 17 or 20, and increased androgen receptor (AR) mRNA in the magnum on Days 6 and 13 and in the shell gland on Day 13. A fasting-induced elevation in ovocalyxin-36 mRNA expression on Day 6 and a decrease in avidin mRNA on Days 6 and 13 and in ovocleidin-116 on Day 13 were also observed (P < 0.05 to P < 0.001). Administration of chGH abolished the fasting-induced decrease in the concentration of steroids in plasma and tissues. Furthermore, chGH enhanced the effect of fasting on mRNA expression of PR, ERα, and avidin in the magnum on Day 6, and ERα in the shell gland on Day 13. The gene expression of ovalbumin on Days 6 and 13, ovocalyxin-36 and ovocleidin-116 on Day 6 was decreased in chGH-treated chickens. In contrast, the expression of ovalbumin on Day 17 or 20 was increased (P < 0.05 to P < 0.001). The results obtained indicate that, by alterations in the concentration of steroid hormones and their receptor expression in the chicken oviduct, GH determines the rate of regression and rejuvenation of this organ during molting. Moreover, changes in the expression of selected egg proteins indicate that GH might be the regulator of the secretory activity of the hen oviduct.
本研究旨在探讨产蛋间歇期生长激素(GH)处理对以下方面的影响:(1)血浆和输卵管组织中类固醇的浓度;(2)类固醇受体mRNA的表达;(3)鸡输卵管中选定的卵特异性蛋白的mRNA表达。通过禁食5天诱导产蛋暂停,随后隔天喂食,从第10天起每天喂食。将鸡分为三组:自由采食对照组(n = 18)、经历产蛋暂停组(n = 18)和经历产蛋暂停且每天注射200μg/kg体重鸡生长激素(chGH)组(n = 18)。在实验的第6天(输卵管退化时)、第13天(输卵管再生期间)以及第17天或第20天(输卵管恢复活力时),从每组母鸡中分离出输卵管。禁食导致第6天血浆中孕酮(P4)、睾酮和雌二醇浓度降低,以及第6天和第13天这些类固醇的组织浓度降低。禁食还导致第6天输卵管膨大部和壳腺中雌激素受体α和β(ERα、ERβ)以及孕酮受体(PR)的相对表达增加,第13天和第17天或第20天输卵管膨大部中ERα和PR增加,第6天和第13天输卵管膨大部以及第13天壳腺中雄激素受体(AR)mRNA增加。还观察到禁食诱导第6天卵钙蛋白-36 mRNA表达升高,第6天和第13天抗生物素蛋白mRNA降低,第13天卵壳蛋白-116降低(P < 0.05至P < 0.001)。chGH的施用消除了禁食诱导的血浆和组织中类固醇浓度的降低。此外,chGH增强了禁食对第6天输卵管膨大部中PR、ERα和抗生物素蛋白mRNA表达以及第13天壳腺中ERα表达的影响。chGH处理的鸡在第6天和第13天卵清蛋白的基因表达、第6天卵钙蛋白-36和卵壳蛋白-116的基因表达降低。相反,第17天或第20天卵清蛋白的表达增加(P < 0.05至P < 0.001)。所得结果表明,通过改变鸡输卵管中类固醇激素的浓度及其受体表达,GH决定了该器官在换羽期间的退化和恢复活力的速率。此外,选定卵蛋白表达的变化表明GH可能是母鸡输卵管分泌活性的调节因子。