College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China.
Poult Sci. 2013 Aug;92(8):1951-61. doi: 10.3382/ps.2012-02909.
Osteocalcin (OC) is a sensitive biochemical marker for evaluating bone turnover in mammals. The role of avian OC is less clear because of the need for a chicken assay. Our objectives were to develop an assay using indirect competitive ELISA for detecting chicken serum OC and use the assay to examine the effects of perches on bone remodeling in caged hens. Anti-chicken OC polyclonal antibody was produced by immunization of rabbits with a recombinant OC from Escherichia coli. Chicken OC extracted from bone was used as a coated protein, and purified chicken OC was used for calibration. The limit of detection of the developed OC ELISA was 0.13 ng/mL. The intra- and interassay CV were <7 and <12%, respectively. The sensitivity of the developed OC ELISA was compared with a commercial Rat-Mid OC ELISA in laying hens housed in conventional cages with or without perches. Serum samples were collected from 71-wk-old White Leghorn hens subjected to 4 treatments. Treatment 1 was control chickens that never had access to perches during their life cycle. Treatment 2 chickens had perches during the pullet phase (0 to 16.9 wk of age), whereas treatment 3 chickens had perches only during the egg-laying phase of the life cycle (17 to 71 wk of age). Treatment 4 chickens always had access to perches (0 to 71 wk of age). Correlation between the 2 assays was 0.62 (P < 0.0001). Levels of serum OC using the developed chicken ELISA were higher than that detected using the Rat-Mid ELISA (P < 0.0001). Results from the chicken ELISA assay showed that hens with perch access had higher concentrations of serum OC than hens without perches during egg laying (P = 0.04). Pullet access to perches did not affect serum OC levels in 71-wk-old hens (P = 0.15). In conclusion, a chicken OC ELISA has been validated that is sensitive and accurate with adequate discriminatory power for measuring bone remodeling in chickens.
骨钙素 (OC) 是评估哺乳动物骨转换的敏感生化标志物。由于需要鸡检测，鸟类 OC 的作用尚不清楚。我们的目标是开发一种间接竞争 ELISA 检测鸡血清 OC 的方法，并利用该方法研究栖木对笼养鸡骨重塑的影响。用重组 OC 对兔子进行免疫产生抗鸡 OC 多克隆抗体。用骨提取的鸡 OC 作为包被蛋白，用纯化的鸡 OC 进行校准。所开发的 OC ELISA 的检测限为 0.13ng/ml。批内和批间 CV 分别小于 7%和 12%。将所开发的 OC ELISA 的敏感性与传统笼养条件下有无栖木的产蛋母鸡的商业 Rat-Mid OC ELISA 进行了比较。从 71 周龄白来航母鸡中采集血清样本，这些母鸡接受了 4 种处理。处理 1 是对照组，母鸡在其生命周期中从未接触过栖木。处理 2 中的母鸡在育雏期（0 至 16.9 周龄）有栖木，而处理 3 中的母鸡仅在生命周期的产蛋期（17 至 71 周龄）有栖木。处理 4 中的母鸡始终可以使用栖木（0 至 71 周龄）。两种检测方法的相关性为 0.62（P<0.0001）。用开发的鸡 ELISA 检测到的血清 OC 水平高于用 Rat-Mid ELISA 检测到的水平（P<0.0001）。鸡 ELISA 检测结果表明，有栖木的母鸡在产蛋期的血清 OC 浓度高于没有栖木的母鸡（P=0.04）。育雏期接触栖木不会影响 71 周龄母鸡的血清 OC 水平（P=0.15）。总之，已经验证了一种鸡 OC ELISA，该方法具有足够的区分能力，对测量鸡的骨重塑具有较高的灵敏度和准确性。
