Effect of calcitonin or the anabolic steroid Decadurabolin on serum beta 2 microglobulin in osteoporotic postmenopausal women.

β 2 -Microglobulin (B 2 m) is a small polypeptide of 99 amino acids with a molecular weight of 11.800. It is found in serum, on the surface of almost all mammalian cells and is part of the surface antigen of the cell membrane of human lymphocytes. Moreover, the heavy chain of major histocompatibility complex class I molecules normally associates in the membrane with B 2 m. According to Canalis, et al this polypeptide is a bone derived growth factor