| Research Abstract |
Pinealectomized chickens ax known to develop scoliosis, but the mechanism underlying this phenomenon is unknown. On the other hand, the pineal gland at 1 day-old chick shows a ciicadian rhythm, however, the rhythm dumps out in accordance with aging. Therefore, we investigated the role of a arcadian dock in the pineal gland on the spinal deformity. We examined the rate of spinal deformity in the broilers that are pinealectomized at different ages. The rate of spinal deformity decreased in accordant with removal day of age. These results suggest that the Orcadian dock in the pineal gland is important to develop the spine. We conducted the next study to verify two proposed hypotheses lor the etiology of the spinal deformity: asymmetric growth cfliievertebral bone and the buckling. Tnerefore the influence of body growth on the degree of spinal deformity was investigated Piiiealectomized broilers at 1 day-old were kept under different dietary foods for 2 weeks. Tne mean degree of the spinal deformity in full, 75, and 50% diet was 50,38 and 13°, respectively. These residta show that the induction of spinal deformity in pinealectomized chicks is related to the body growth. Futhermore, the pinealectomized diiciks were sacrificed at 4 days old, and the 76 vertebra was collected and examined ossification in the anterior and posterior parts of the vertebral bone. No difference was found in ossification in the anterior part of vertebral bone, but the area of ossification in the posterior part was significantly larger (P<0.001) in the pinealectomized chicks. At present, scoliotic deformities were thought to occur as a result of causing differences in bone growth between the anterior and posterior elements of the vertebral column, and the buckling phenomenon caused by the marked increase of the body growth.
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