Progressive Increase in Nonsex Hormone-Binding Globulin-Bound Testosterone from Infancy to Late Prepuberty in Boys

摘要: Recent evidence suggests that human albumin-bound testosterone (HSA-bound T), the major constituent of nonsex hormone-binding globulin-bound T (non-SHBG-bound is biologically important. To examine potential exposure peripheral tissues to in normal prepubertal boys, we determined distribution serum into SHBG-bound, HSA-bound, non-SHBG-bound, and free fractions 80 males, aged 0.5-14 yr, all at Tanner stage I sexual development. A model assuming equilibrium between bound 2-binding proteins (HSA SHBG) was used. computer program, using as constants SHBG-T HSA-T affinity HSA concentration variables SHBG total concentrations, used calculate SHBG-bound T, HSA-bound non-SHBG-bound T. Serum increased 2.6-fold from 0.5 14 whereas 8- 9-fold during same period. On other hand, only 1.9-fold. Expressed a function 6.6% 30.4%, relative increment being greater for than We conclude with advancing age, there progressive increase boys. At level central nervous system, this bioavailable could induce maturative changes brain cells result onset puberty