Howell J M, Pitt G A, Thompson J N
Br J Exp Pathol. 1969 Apr;50(2):181-6.
Twenty-five cocks aged 7 months and 43 hens aged 18 months had been fed from hatching diets free from retinol but supplemented with retinoic acid. The retinoic acid supplement was withdrawn from 20 cocks and 23 hens and the birds developed signs of vitamin A deficiency. The deficient birds together with control birds fed retinyl acetate were killed and examined at intervals throughout the 18 days of the experiment. Observations were made on clinical signs; changes in tissues, particularly nasal epithelium, nervous system and bone, and cerebrospinal fluid pressures were recorded. The behaviour of the deficient birds was abnormal by the 3rd day of the experiment, a degree of incoordination was seen after the 6th day, and by the 10th day the weight of the deficient birds was significantly lower than that of the controls. Changes in nasal epithelium and in the periosteum lining the cranial cavity and vertebral canal were seen by the 3rd day of the experiment and after 6 days new spicules of bone were being formed. Compression of central nervous system and nerve fibre degeneration were well established by the 10th day. Dramatic changes in the cerebrospinal fluid pressure were not seen. Only 2 deficient birds had values outside the normal range and these were both recorded at the end of the experiment. These results are discussed and we conclude that the CNS compression is related to the increased deposition of periosteal bone.
25只7月龄公鸡和43只18月龄母鸡自孵化起就饲喂不含视黄醇但添加了视黄酸的日粮。从20只公鸡和23只母鸡中停止添加视黄酸，这些鸡出现了维生素A缺乏的症状。在整个18天的实验过程中，定期宰杀缺乏维生素A的鸡以及饲喂醋酸视黄酯的对照鸡并进行检查。观察临床症状；记录组织变化，特别是鼻上皮、神经系统和骨骼的变化以及脑脊液压力。实验第3天，缺乏维生素A的鸡行为异常，第6天后出现一定程度的不协调，到第10天，缺乏维生素A的鸡体重明显低于对照鸡。实验第3天观察到鼻上皮以及颅腔和椎管内衬骨膜的变化，6天后开始形成新的骨针。到第10天，中枢神经系统受压和神经纤维变性已很明显。未观察到脑脊液压力的显著变化。只有2只缺乏维生素A的鸡的值超出正常范围，且均在实验结束时记录到。对这些结果进行了讨论，我们得出结论，中枢神经系统受压与骨膜骨沉积增加有关。
