The
administration of a combination of
testosterone undecanoate (TU, a long-acting
androgen) and
depo-medroxyprogesterone acetate (DMPA) were investigated in term of
suppression of
rat sperm concentration in vivo to
azoospermia through increasing activity of spermatogenic
cell caspase 3.
Adult Sprague Dawley rats received TU and DMPA of 2.5 mg and 1.25 mg, respectively, a regimen known to rapidly reduce intra testicular
testosterone and to produce
azoospermia within 12 weeks.
Caspase 3 positive
sperm cells increased compared with control levels during 6 weeks post-
injection and increased further through 60 weeks.
Immunohistochemistry for
caspase 3 revealed that
spermatocytes represented the predominant
caspase 3 positive
germ cells. Modest immunoreactivity for
caspase-3 was localized to nuclear region of the
germ cells of control and treated
testes.
Immunohistochemistry study revealed significantly increased
caspase-3 expression in nuclei of
germ cells during
administration of TU+DMPA to
rats. Additionally, the
caspase 3 content was significantly increased in
germ cells during
rats were administered TU+DMPA (453.90±84.88
cells/200
seminiferous tubules) and
caspase 3 significant increase in immunoreactivity was localized to the nuclei of
spermatogonia,
spermatocytes, and
spermatids. Taken together, these results indicated that
azoospermia due to reduced intratesticular
testosterone concentration was
caspase-3 activation dependent and suggested that the increase in active
caspase-3 in the nucleus may be involved in the induction of decreased
sperm production.