To evaluate the effects of Tamoxifen
(TMX) and trifluoperozine (TFP) on pinealectomized chicken scoliosis
Summary of Background Data.
probably due to the lack of melatonin. In addition to other functions, melatonin also acts as a calmodulin
antagonist. We postulate that loss of this antagonistic effect may be the cause of scoliosis
in this model. TMX and TFP are known calmodulin
antagonists, which may alter the incidence and severity of scoliosis
Seventy-two newly hatched chicken
that underwent surgical pinealectomy
within 72 hours of hatching were divided into 3 groups of 24 animals in each as group I (control), group II (TMX), and group III (TFP). TMX and TFP were given to groups II and III, respectively, for 10 weeks with the dose of 0.1 mg/kg/d, whereas the control group received no medication. AP scoliosis
radiographs were obtained at seventh and 10th week to evaluate coronal spinal alignment.
Three chickens in group I, 2 chickens in group II, and 1 chicken
in group III died in the first postoperative week. Scoliosis
incidences and magnitudes were similar among groups at seventh and 10th week. TMX and TFP groups showed decreases of incidence of upper cervical, lower cervical, lower cervical-thoracic-lumbar curves at 10th week compared with seventh week. TMX group showed a decline in thoracic region mean Cobb angle, whereas control group showed an increase (P
= 0.048). TMX group showed a more prominent decline in cervicothoracic region mean Cobb angle compared with control group (P
The incidence and magnitude of scoliosis
in pinealectomized chicken
may be decreased by the administration of TMX, presumably because of this drugs' calmodulin
antagonism. Further studies on higher animals and dosage and timing are required.