Mechanism of spinal deformity produced by pinealectomy and the role of a circadian dock of the pineal gland on developing the spine in the chick

已知松果体切除的鸡会发生脊柱侧凸，但这种现象的机制尚不清楚。另一方面，1日龄雏鸡的松果体表现出一种昼夜节律，但随着年龄的增长，这种节律逐渐消失。因此，我们研究了松果体中昼夜节律dock在脊柱畸形中的作用。我们研究了在不同年龄切除松果体的肉鸡脊柱畸形的发生率。脊柱畸形率随手术日龄的增加而降低。这些结果表明，松果体中的Orcadian dock对脊柱的发育很重要。我们进行了下一项研究，以验证关于脊柱畸形病因的两种假设：不对称生长的椎体骨和屈曲。为此，研究体生长对1日龄去骨肉仔鸡脊柱畸形程度的影响，饲喂不同饲粮2周。在完全、75%和50%饮食中，脊柱畸形的平均程度分别为50°、38°和13°。这些结果表明，松果体切除雏鸡脊柱畸形的发生与机体生长有关。4日龄处死松果体切除的椎体，收集76椎体，检查椎骨前后的骨化情况。去松果体的雏鸡椎骨前部骨化面积无显著差异，但后部骨化面积显著增大（P<0.001）。目前认为脊柱侧凸畸形的发生是由于引起脊柱前后部骨生长的差异，以及身体生长明显增加而引起的屈曲现象。

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.