Controlled clinical study.
To compare muscle and platelet calmodulin and melatonin concentrations of scoliotic and nonscoliotic populations.
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.
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.
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.
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.
Idiopathic scoliosis patients and nonscoliotic control population showed no difference between muscle and platelet ratios of melatonin and calmodulin. Scoliotic patients showed asymmetric distribution of calmodulin in their paravertebral muscles. Convex side calmodulin ratios were higher compared with concave side. Platelet values are not representative for muscle melatonin or calmodulin.
From the *Department of Orthopedics and Traumatology, Hacettepe University, Ankara, Turkey; and †Department of Orthopedic Surgery, University of California San Francisco, San Francisco, CA.
Acknowledgment date: April 7, 2008. First revision date: July 25, 2008. Second revision date: September 23, 2008. Third revision date: November 4, 2008. Acceptance date: February 25, 2009.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.
Supported by a research grant from Scoliosis Research Society via Cotrel Foundation, Paris, France.
Address correspondence and reprint requests to R. Emre Acaroglu, MD, Department of Orthopedics and Traumatology, Faculty of Medicine, Hacettepe University, Sihhiye, Ankara, 06100 Turkey; E-mail: firstname.lastname@example.org