Am. Mahmoud et al., INHIBIN AND STEROID-RESPONSE TO TESTICULAR STIMULATION WITH PURE FSH (METRODIN) IN INFERTILE MEN WITH UNILATERAL CRYPTORCHIDISM, Andrologia, 28(2), 1996, pp. 103-108
Static measurements of immunoreactive inhibin have proven of little re
levance in the diagnosis of testicular disorders. Dynamic evaluation o
f the inhibin secretory reserve might detect a specific Sertoli cell d
efect in a subgroup of infertile men. We compared the response of inhi
bin and steroids to an intravenous injection of pure FSH (Metrodin, Se
rono, 300 IU) in 13 infertile men with unilateral cryptorchidism to th
at in eight normal fertile men. Blood was aspirated before, 24, 48, an
d 72 h after the FSH injection. Two subgroups of patients with unilate
ral cryptorchidism were detected: those who responded by secreting inh
ibin in a pattern similar to normal men (seven patients), and those wh
o responded poorly or not at all (six patients). The presumed cause of
this difference is a defect of Sertoli cell reserve function due to a
combination of insults to the testes, and not to cryptorchidism itsel
f. The difference in response to FSH cannot be predicted from semen an
alysis nor from static hormone measurements. Overall, inhibin levels c
orrelated significantly with the serum concentrations of FSH (r=-0.36,
P<0.05), testosterone (r=0.37, P<0.05), and 17-hydroxyprogesterone (r
=0.66, P<0.001). It is concluded that, in infertile men with unilatera
l cryptorchidism, stimulation of Sertoli cells by FSH can identify a s
ubgroup of patients with Sertoli cell malfunction involving inhibin sy
nthesis.