Decline in serum antimüllerian hormone due to androgen action in early puberty in males

Abstract

We read with interest the recent article by Hero et al. (1) showing that antimüllerian hormone (AMH) is one of the earliest early signs of pubertal development in healthy boys, occurring before any notable increase in testis volume or serum testosterone can be noticed. Owing to its longitudinal design, this study provides conclusive evidence for similar observations made in previous cross-sectional studies indicating that the early increase in intratesticular testosterone is responsible for the inhibition of AMH expression (2-4). The authors conclude from their results that Sertoli cells must begin to express the androgen receptor before the clinical onset of puberty. This does not contradict what was reported by Boukari et al (5), who did not report the existence of androgen receptor in peri-pubertal boys because their study only included fetal, newborn and adult testis samples. Interestingly, a recent study of our group (6) described that androgen receptor expression is first observed in the nuclei of few Sertoli cells at the age of 5 months. Weak labeling can be seen in 2?15% of Sertoli cells until 4 years of age and progressively increases to high levels of androgen receptor expression in more than 90% of Sertoli cell nuclei by the age of 8 years (Figure 1). Thereafter, an intense signal is present in almost all Sertoli cells. The presence of androgen receptor in boys older than 8 years explains the early pubertal decline of AMH induced by intra-testicular testosterone rise.