Comparison of the melatonin and calmodulin in paravertebral muscle and platelets of patients with or without adolescent idiopathic scoliosis.
METHODS
Controlled clinical study. OBJECTIVE.: To compare muscle and platelet calmodulin and melatonin concentrations of scoliotic and nonscoliotic populations.


BACKGROUND
Melatonin and calmodulin are potential key molecules in scoliosis etiology. Calmodulin is not only a second messenger of melatonin but also has been shown to have effects on muscle contractility. There is a possibility that it may be of importance in the regulation of spinal alignment. Platelets have been defined as mini muscles calmodulin and melatonin levels of which may be the projections of muscle values.


METHODS
Twenty patients undergoing posterior surgery for adolescent idiopathic scoliosis (AIS) and 9 thoracic-lumbar trauma patients undergoing posterior surgery constituted the population. Autologous bloods were collected and processed to obtain platelets. Paravertebral muscle tissue samples from both sides were obtained at T12-L1 level intraoperatively. Muscle and platelet samples were analyzed for the levels of melatonin by radio immuno assay and for calmodulin by enzyme-linked immunosorbent analysis. Groups, concave (left side for the control group) and convex side (right side for the control group), muscles and platelet median protein concentrations, and optic densitometry (OD) ratio values were compared.


RESULTS
AIS group consisted of 2 male and 18 female patients. Mean age was 16.1 +/- 3.78 (11-29). Control group consisted of 5 male and 4 female patients. Mean age was 35 +/- 13.47 (16-55). Platelet Calmodulin OD/Supernatant's OD ratios and both convex and concave sides' muscle Calmodulin OD/Supernatants' OD ratios were not different between groups. On the other hand, convex side muscle calmodulin to total muscle calmodulin ratios were higher in AIS group compared with concave (P = 0.048); likewise, concave side calmodulin to total calmodulin ratios were lower in AIS group compared with control (P = 0.035). Convex side calmodulin to concave side calmodulin ratios were significantly different among groups (P = 0.048). Neither platelet melatonin to total protein ratios, nor convex or concave side muscle melatonin to total protein ratios, nor convex to concave side melatonin ratios were significantly different between groups. Convex or concave side calmodulin or melatonin values were not correlated with platelet values.


CONCLUSIONS
AIS group had an asymmetric distribution of calmodulin in paraspinal muscle, higher at the convex side and lower at the concave. Neither platelet melatonin nor platelet calmodulin was found to be representative of the muscle protein values.
Acaroglu
Emre
E
Department of Orthopedics and Traumatology, Hacettepe University, Ankara, Turkey. eacarogl@hacettepe.edu.tr
Akel
Ibrahim
I
Alanay
Ahmet
A
Yazici
Muharrem
M
Marcucio
Ralph
R
D000293:Adolescent; D000328:Adult; D001792:Blood Platelets / Q000378:metabolism*; D002147:Calmodulin / Q000032:analysis*; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000293:injuries; D008297:Male; D008550:Melatonin / Q000032:analysis*; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D011863:Radioimmunoassay; D012600:Scoliosis / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D013904:Thoracic Vertebrae / Q000293:injuries; D055815:Young Adult
D002147:Calmodulin; D008550:Melatonin