Study Design. The effect of intraperitoneal injection of 5-hydroxytryp
tophan (5-HTP) versus control in pinealectomized chickens. Objective.
To find if the serotonin may have some role in the cause or treatment
of idiopathic scoliosis. Summary of Background Data. One of the causes
of idiopathic scoliosis is thought to be the disruption of postural r
eflex. Serotonin has been proposed to have a crucial role in maintaini
ng normal postural muscle tone or postural equilibrium. Method. Forty
pinealectomized chickens served as controls, and an additional 40 pine
alectomized chickens received daily intraperitoneal injections of 5-hy
droxytryptophan, a precursor of serotonin, which can pass through the
blood-brain barrier. Spine radiographs were examined to measure the sc
oliotic deformity.Results. Scoliosis developed in all 40 pinealectomiz
ed chickens (control), whereas only 28 chickens in the 5-hydroxytrypto
phan-treated group (6 in severe, 22 in mild) had scoliosis developed.
The remaining 12 chickens grew up with normal spines. Mast chickens wi
th mild scoliosis did not have curve progression but continued to have
wedged vertebrae. Conclusion. Serotonin deficit secondary to a defect
of melatonin may have disturbed postural muscle tone or postural equi
librium resulting in scoliosis in pinealectomized chicken. Prevention
from the development of scoliosis or its progression in chickens treat
ed with 5-hydroxytryptophan suggests that serotonin may have potential
therapeutic value.