The effect of calmodulin antagonists on experimental scoliosis: a pinealectomized chicken model.
METHODS
Randomized controlled.


OBJECTIVE
To evaluate the effects of Tamoxifen (TMX) and trifluoperozine (TFP) on pinealectomized chicken scoliosis.


BACKGROUND
Pinealectomized chicken develops scoliosis 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.


METHODS
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.


RESULTS
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 = 0.009).


CONCLUSIONS
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.
Akel
Ibrahim
I
Department of Orthopedics and Traumatology, Hacettepe University, Ankara, Turkey.
Kocak
Ozgur
O
Bozkurt
Gokhan
G
Alanay
Ahmet
A
Marcucio
Ralph
R
Acaroglu
Emre
E
D000818:Animals; D050071:Bone Density Conservation Agents / Q000494:pharmacology; D002147:Calmodulin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002645:Chickens; D004195:Disease Models, Animal; D018492:Dopamine Antagonists / Q000494:pharmacology; D005260:Female; D008550:Melatonin / Q000172:deficiency; D010870:Pineal Gland / Q000378:metabolism / Q000601:surgery*; D011859:Radiography; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000209:etiology; D012720:Severity of Illness Index; D013629:Tamoxifen / Q000494:pharmacology*; D014273:Triflupromazine / Q000494:pharmacology*
D050071:Bone Density Conservation Agents; D002147:Calmodulin; D018492:Dopamine Antagonists; D013629:Tamoxifen; D008550:Melatonin; D014273:Triflupromazine