Objective To investigate how endothelial nitric oxide (eNOS) expression in
the seminiferous tubules might be related to spermatogenesis, by examining
eNOS expression in testicular tissue of patients infertile from various cau
Patients and methods The study included five fertile men with a normal sper
m concentration, nine patients with obstructive azoospermia, 20 with varico
cele testes and eight with idiopathic azoospermia (Sertoli cell-only syndro
me). Testicular biopsy specimens were examined by immunohistochemistry for
eNOS protein expression, in addition to a routine pathological assessment,
eNOS protein was detected using an eNOS monoclonal antibody. A Sertoli cell
staining index (SST) was defined as the ratio of stained Sertoli cells per
total number of Sertoli cells, and was compared among the groups.
Results eNOS was localized to Sertoli cells in the seminiferous tubules and
Leydig cells in the interstium; although some degenerating germ cells stai
ned, normal germ cells did not. The SSI was significantly lower in patients
with Sertoli cell-only syndrome than in either fertile men or patients wit
h obstructive azoospermia or varicocele. However, the SSI did not correlate
significantly with the Johnsen score.
Conclusion The expression of eNOS in Sertoli cells may depend on the existe
nce of germ cells and be associated with germ cell development.