Klandorf H, Blauwiekel R, Qin X, Russell R W
Division of Animal and Veterinary Sciences, West Virginia University, Morgantown 26506-6108.
Gen Comp Endocrinol. 1992 Jun;86(3):469-82. doi: 10.1016/0016-6480(92)90072-r.
The effect of estradiol-17 beta (E2) given as a sustained-release implant (Compudose 200) on concentrations of plasma calcium (Ca) and the development of the chick shell gland has been investigated in food-restricted and thyroid hormone-treated 6- to 8-week-old broiler breeder pullets. Chicks implanted with 0, 0.5, 1.0, 1.5, 2.0, and 3.0 Compudose pellets for 24 days (n = 6/group) revealed a dose-response relationship between plasma E2 and Ca and on oviduct growth. Plasma E2 concentrations were characterized by an initial burst phase for approximately 17 days, followed by a constant release phase. Histologic examination of shell gland tissue confirmed the dose related E2-induced development of microvilliated epithelium and tubular glands over time. Feed restriction initiated at 2 weeks of age markedly increased the response to the E2 implants. Birds (n = 8/group) implanted with 2 pellets and feed restricted had increased plasma concentrations of E2 and Ca, and increased growth of the oviduct (P less than 0.01) as compared to ad libitum implanted birds. In a separate study birds (n = 6/group) had restricted access to feed from 8 weeks of age and were implanted with 0, 2, 4, or 8 pellets. At intervals from 9 to 45 days after implantation one bird from each group was killed. Although concentrations of plasma Ca were significantly greater in feed-restricted birds (P less than 0.01), oviduct growth was only marginally increased by the food restriction program. Plasma Ca concentrations in broiler breeder pullets (n = 8/group) implanted with 1 or 3 pellets and injected with T3/T4 (100 micrograms/day) were significantly decreased (P less than 0.05). Injection of thyroid hormone also marginally decreased shell gland epithelial cell height (P less than 0.05) and development of microvilli (P less than 0.05). There was no effect of the administration of the goitrogen, propylthiouracil (10 micrograms/day im), on the E2 induced development of the shell gland.
在限食和甲状腺激素处理的6至8周龄肉种鸡小母鸡中，研究了以缓释植入物（Compudose 200）形式给予的17β-雌二醇（E2）对血浆钙（Ca）浓度和鸡壳腺发育的影响。植入0、0.5、1.0、1.5、2.0和3.0个Compudose丸粒24天的雏鸡（每组n = 6）显示血浆E2与Ca以及输卵管生长之间存在剂量反应关系。血浆E2浓度的特征是最初约17天的爆发期，随后是持续释放期。对壳腺组织的组织学检查证实，随着时间的推移，E2诱导的微绒毛上皮和管状腺的发育与剂量相关。2周龄开始限食显著增加了对E2植入物的反应。与自由采食植入的鸡相比，植入2个丸粒并限食的鸡（每组n = 8）血浆E2和Ca浓度升高，输卵管生长增加（P < 0.01）。在另一项研究中，鸡（每组n = 6）从8周龄开始限食，并植入0、2、4或8个丸粒。在植入后9至45天的间隔时间，每组处死一只鸡。尽管限食鸡的血浆Ca浓度显著更高（P < 0.01），但限食方案仅使输卵管生长略有增加。植入1或3个丸粒并注射T3/T4（100微克/天）的肉种鸡小母鸡（每组n = 8）的血浆Ca浓度显著降低（P < 0.05）。注射甲状腺激素也使壳腺上皮细胞高度略有降低（P < 0.05）和微绒毛发育略有降低（P < 0.05）。给予甲状腺肿剂丙基硫氧嘧啶（10微克/天，肌肉注射）对E2诱导的壳腺发育没有影响。
