The experimental study of scoliosis in bipedal rat in lathyrism.

Using Wister albino rats, bipedal rats were prepared; to which semicarbazide at a concentration of 0.075%, 0.05% and 0.025% were given as drinking water and the rats were divided into three groups A, B and C according to such concentrations. Osteolathyrism was caused in this way and the relations between doses as well as the dosing period and the progress of scoliosis were examined roentgenologically and histologically and the following conclusions were obtained. 1. The frequency of occurrence of scoliosis was 82% in the bipedal rats and 13% in the quadrupedal rats (level of significance alpha = 0.001% or less). 2. Primordial top vertebrae were located concentratively in the lower 1/3 of thoracic vertebra. 3. In the primordial curve, those cases showing a right side curve accounted for 76%. 4. After termination of administration of semicarbazide, spontaneous improvement took place only in those cases showing scoliosis of less than 40 degrees. 5. In the author's experimental scoliosis, the static and dynamic condition of posture nearly coincided with those of men in clinical studies. 6. Histological changes were especially marked in the cartilage layer on the vertebral epiphyseal line, being quite diversified.