Steroid hormone receptors, protein, and DNA in erector spinae muscle from scoliotic patients

To investigate the possible influence of steroid hormones on the back muscles of scoliotic patients, steroid receptors, protein, and DNA were analyzed in muscle from 20 patients of both sexes, at different ages, and with different clinical diagnoses. Androgen and glucocorticoid receptors, but no estrogen receptors, were found. The androgen and glucocorticoid receptors had binding characteristics similar to those of corresponding receptors in other mammalian skeletal muscle, including that of humans. Whereas the concentration of androgen receptors was similar on both sides of the curve, the concentration of glucocorticoid receptors per gram of tissue (wet weight) was higher on the convex side. There were no side differences in steroid receptor content when measured per milligram of protein or per milligram of DNA. The concentrations of protein and DNA were higher on the convex than on the concave side and resulted in lower protein/DNA ratios on the former side indicating smaller 'cell units' in muscle on the convex side. These data suggest that the side differences in scoliotic erector spinae muscle for these growth parameters can be secondary to the reported different distribution of fiber types on both sides, but they can also be due to a difference in growth of the muscle cells on the two sides.