Rath N C, Huff W E, Balog J M, Huff G R
PPPSRU, Agricultural Research Service, USDA, Poultry Science Center, University of Arkansas, Fayetteville, Arkansas 72701, USA.
Poult Sci. 2004 Feb;83(2):266-74. doi: 10.1093/ps/83.2.266.
Tibial dyschondroplasia (TD) is a metabolic cartilage disease in poultry the natural etiology of which is not known. In the absence of biomarkers to monitor the initiation and progression of the naturally occurring disease, experimentally induced TD can provide a suitable venue to study the mechanism of its pathogenesis. Therefore, the objective of this study was to establish a streamlined experimental protocol to induce TD using dithiocarbamates and to determine a time course of its progression. Three different dithiocarbamates, dimethyldithiocarbamate, pyrrolidine dithiocarbamate, and tetramethyl thiuram disulfide (thiram), were tested with respect to their abilities to induce TD and affect different physiological factors. Our results show that chickens fed thiram during the first 2 wk of age showed a maximum TD index. Thiram appeared to be the most potent of the 3 dithiocarbamates with dimethyldithiocarbamate having the least ability to induce TD and pyrrolidine dithiocarbamate showing an intermediate potency. A transient exposure to thiram for a day or 2 was sufficient to markedly increase the incidence of TD and produce lasting damage as determined by the presence of severe lesions in a high percentage of birds at 2 to 3 wk after the treatment. Thiram affected the chondrocyte morphology of maturing zone cartilage evident by nuclear shrinkage and emptied chondrocyte lacunae during later times and also involutions of capillary vessels. Such changes were not seen in prehypertrophic zone chondrocytes of the same growth plates. Thiram reduced the BW, increased blood heterophil-to-lymphocyte ratios, and elevated serum corticosterone concentrations indicating physiological stress. However, there was no change in relative liver weights or blood clinical chemistry including the serum concentrations of Ca, P, and Cu in thiocarbamate-fed chickens. Induction of TD in young chickens by means of a short feeding protocol with thiram may be useful to study the mechanisms of pathogenesis of TD and to identify micronutrients that can provide protection against this disease.
胫骨软骨发育不良（TD）是家禽的一种代谢性软骨疾病，其天然病因尚不清楚。由于缺乏用于监测自然发生疾病的起始和进展的生物标志物，实验性诱导的TD可为研究其发病机制提供合适的途径。因此，本研究的目的是建立一种使用二硫代氨基甲酸盐诱导TD的简化实验方案，并确定其进展的时间进程。测试了三种不同的二硫代氨基甲酸盐，即二甲基二硫代氨基甲酸盐、吡咯烷二硫代氨基甲酸盐和四甲基秋兰姆二硫化物（福美双）诱导TD的能力以及对不同生理因素的影响。我们的结果表明，在1至2周龄期间饲喂福美双的鸡表现出最高的TD指数。福美双似乎是三种二硫代氨基甲酸盐中最有效的，二甲基二硫代氨基甲酸盐诱导TD的能力最弱，吡咯烷二硫代氨基甲酸盐表现出中等效力。短暂暴露于福美双1天或2天足以显著增加TD的发病率并造成持久性损伤，这可通过处理后2至3周时高比例的鸡出现严重病变来确定。福美双影响成熟区软骨的软骨细胞形态，后期表现为细胞核收缩和软骨细胞陷窝空虚，同时毛细血管也出现退化。在同一生长板的肥大前区软骨细胞中未观察到此类变化。福美双降低了体重，增加了血液中嗜异性粒细胞与淋巴细胞的比例，并提高了血清皮质酮浓度，表明存在生理应激。然而，在饲喂硫代氨基甲酸盐的鸡中，相对肝脏重量或血液临床化学指标（包括血清钙、磷和铜浓度）没有变化。通过用福美双进行短期饲喂方案在幼鸡中诱导TD可能有助于研究TD的发病机制，并识别可提供针对该疾病保护作用的微量营养素。
