Biphasic increase in serum inhibin B during puberty: a longitudinal study of healthy Finnish boys.
We investigated the concentrations of serum inhibin B and the pro-alphaC-containing inhibins (pro-alphaC inhibin) and their relations to serum FSH levels in 38 healthy boys during their progression through puberty. Furthermore, we studied the effect of recombinant human FSH (rhFSH) on pro-alphaC inhibin production in three prepubertal gonadotropin-deficient boys. The serum inhibin B level increased between Tanner stages G1 and G2 (p < 0.02), simultaneously with the serum LH and testosterone concentrations. In advanced puberty, inhibin B changed less, and at stage G4, correlated negatively with serum FSH level (r = -0.57, p < 0.001, n = 37). The serum pro-alphaC inhibin level changed differently and increased also in advanced puberty. In prepubertal healthy subjects, the serum pro-alphaC inhibin and FSH levels correlated positively (r = 0.50, p = 0.051, n = 16), and during the rhFSH treatment of gonadotropin-deficient boys, serum pro-alphaC inhibin levels increased. These findings suggest that an increased production of inhibin B is an early event in puberty and that inhibin B can inhibit pituitary FSH secretion in the course of sexual maturation. Furthermore, they suggest that during puberty free inhibin (pro)-alpha-subunits, detected by the pro-alphaC inhibin assay, are present in large amounts and that FSH stimulates their production by prepubertal testes.
Hospital for Children and Adolescents, University of Helsinki, Finland.
T
T
Raivio
A
A
Perheentupa
A S
AS
McNeilly
N P
NP
Groome
R
R
Anttila
M A
MA
Siimes
L
L
Dunkel
D002648:Child; D005387:Finland; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007265:Inhibins / Q000097:blood*; D008137:Longitudinal Studies; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D011498:Protein Precursors / Q000097:blood; D011627:Puberty / Q000097:blood*; D012016:Reference Values; D013737:Testis / Q000033:anatomy & histology; D013997:Time Factors
D011498:Protein Precursors; C095971:inhibin-alpha subunit precursor; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone