Human blood contains both the uncleaved precursor of anti-Müllerian hormone and a complex of the NH2- and COOH-terminal peptides

Michael W. Pankhurst, Ian S. McLennan
2013 American Journal of Physiology. Endocrinology and Metabolism  
Pankhurst MW, McLennan IS. Human blood contains both the uncleaved precursor of anti-Müllerian hormone and a complex of the NH2-and COOH-terminal peptides. Müllerian hormone (AMH) in blood is a marker of ovarian status in women and the presence of cryptic testes in babies. Despite this, the molecular form of AMH in blood has not been verified. AMH is synthesized as an inert proprotein precursor (proAMH), which can be cleaved to yield NH2-terminal (AMHN) and COOH-terminal (AMHC) fragments, that
more » ... C) fragments, that can complex noncovalently (AMHN,C). Developing males have 10-fold more AMH than young adults. We report here that human blood is a mixture of inactive proAMH and receptor-binding AMH N,C. The AMH in the blood of boys, men, and premenopausal women was immunoprecipitated using antibodies to the NH2-and COOH-terminal peptides. The precipitated proteins were then analyzed by Western blots, using recombinant proteins as markers. The glycosylation status of AMH was verified using deglycosylating enzymes. The NH 2-terminal antibody precipitated a major protein that migrated alongside rhproAMH and was detected by anti-AMHN and anti-AMHC. This antibody also precipitated significant levels of AMHN and AMHC from all participants. Antibodies specific to AMHC precipitated rhAMHC but did not precipitate AMHC from human blood. Hence, all the AMHC in human blood appears to be bound to AMHN. Both AMHN and proAMH were glycosylated, independent of age and sex. In conclusion, boys and young adults have the same form of AMH, with a significant proportion being the inactive precursor. This raises the possibility that the endocrine functions of AMH are partly controlled by its cleavage in the target organ. The presence of proAMH in blood may confound the use of AMH for diagnosis. sex; boys; anti-Müllerian hormone enzyme-linked immunosorbent assay; pro-anti-Müllerian hormone; amino-and carboxy-terminal anti-Müllerian hormone; menopause; ovarian reserve; furin THE HORMONAL CONCENTRATION of anti-Müllerian hormone (AMH, also known as Müllerian-inhibiting substance) varies with sex and age. AMH is initially male specific, with male embryos and prepubescent boys having high levels of AMH in their blood (2, 16). AMH triggers the degeneration of the uterine precursor in early male embryos, after which it contributes to the male biases in the lung (7), brain (19, 21, 32, 34) , and possibly other tissues. The levels of AMH diminish markedly in boys as they approach puberty, with ovarian production being initiated in young girls, after which it slowly rises as they mature (2, 12). Consequently, young men and women have similar levels of AMH, which are about 10% of those in boys (2, 15). Despite this, the adult levels of AMH are sufficient to strongly activate Address for reprint requests and other correspondence: M. Pankhurst, Lindo Ferguson Bldg., Great King St.,
doi:10.1152/ajpendo.00395.2013 pmid:24045871 fatcat:j2hsvatvwjhm5j6vg7kkk66fz4