Nutritional and physiological studies on the regulation of egg white protein synthesis in the chicken

1. 在体内测定了蛋鸡各组织的蛋白质合成。结果发现，肝脏和输卵管中蛋白质合成的分步速率比其他任何测试组织都要快，并且所观察到的分步合成速率的差异几乎完全可以用RNA：蛋白质比率的变化来解释。与l -异构体相比，用dl -蛋氨酸测量的蛋白质合成被发现低估了4 - 36%。建立了一个预测替代仔鸡生长的数学模型，特别考虑了采食量的季节变化。结果表明，对食物摄取量的预测需要对环境温度进行5 ~ 6周的延迟。测定了产蛋周期蛋鸡组织和全身蛋白质合成水平。肝脏和全身的蛋白质合成没有改变。当卵子停留在那里时，Magnum蛋白的合成值最高。另一方面，在其他组织中，当卵子停留在母体中时，蛋白质合成最低。甾体激素处理促进了未成熟雏鸡输卵管的生长。雌激素和睾酮联合使用比单独使用雌激素效果更明显。研究了三种未成熟雏鸡输卵管对类固醇反应性的品系差异。蛋型雏鸡的反应最高，其次为两用型，肉型次之。需要进一步的研究来阐明遗传因素与类固醇治疗反应性之间的关系。

1. Protein synthesis in individual tissues of laying hens was measured in vivo. It was found that fractional rates of protein synthesis in liver and oviduct were faster than those in any other tissues tested, and that the observed differences in fractional synthesis rates almost entirely accounted for by changes in RNA:protein ratios.2. Protein synthesis measured with DL-methionine was found to be underestimated by 4 to 36% in comparison with that measured with the L-isomer.3. A mathematical model for predicting the growth of replacement pullets was constructed with special reference to seasonal variations in food intake. It was found that d delay of 5 - 6 weeks with respect to environmental temperature would be necessary for the prediction of food intake.4. Protein synthesis in tissues and in the whole body of laying hens was measured during the egg formation cycie. Protein synthesis in the liver and in the whole body was not changed. Magnum protein synthesis was at its highest value when an ovum stayed there. In other tissues, on the other hand, protein synthesis was lowest when an ovum stayed in the magnum.5. Stgeroid hormone treatment enhanced the growth of oviduct in immature young chicks. The effect was more evident by the combined administration of estrogen and testosterone than by the administration of estrogen alone.6. Strain difference in the responsiveness of oviduct to steroid treatment was examined in three types of immature chicks. The highest response was found in egg-type chicks, followed by dual-purpose-, and meat-type birds in the decreasing order. Further studies sre necessary to clarify the relationship between genetic factors and responsiveness to steroid treatment.