Serum activin A levels in males and females during pubertal development

Abstract

Activin A is a dimeric protein composed of two βA-subunits protein of the transforming growth factor-β (TGF-β) family. This protein is synthesized by a variety of organs. A sensitive andspecific assay for bioactive dimeric activin A has recently been developed ,to measure circulating levels in adult women and men ,giving a new insights into the possible physiological role of this proteinin the reproductive axis and/or in other functions.The aim of the present study was to evaluate serum dimeric activin A levels in boys and girls during pubertal development. The study was performedon a group of children (n = 54) aged between 6 and 18 years at different Tanner stages. Serum levels of activin A were measured using a specific and sensitive two-site ELISA.Serum activin Alevels were not significantly different at various Tanner stages (Tanner I ,0.36 ± 0.02 ng/ml; Tanner II ,0.33 ± 0.02 ng/ml; Tanner III ,0.35 ± 0.03 ng/ml; Tanner IV ,0.41 ±0.04 ng/ml; Tanner V ,0.35 ± 0.05 ng/ml; p > 0.01). No difference between male and female children was observed.In conclusion ,the lack of significant differences in activin A serumlevels according to the Tanner stages or to gender demonstrates that this protein is not involved in the endocrine modifications during pubertal development and that its measurement may not provide a sensitivenew tool for determining gonadal maturity at puberty.