Abstract
Diabetes induces several malfunctions in male germ cells. The aim of this study was
to analyze the levels and localization of the glucose transporter GLUT8 and insulin
in the testes of rats induced to a diabetic status by a single dose of streptozotocin.
One month after inducing diabetes, the GLUT8 immunoreactivity in diabetic rats was
mainly located associated to the acrosomic system of spermatids, and at low levels
in Leydig cells. Neither the immunohistochemical localization of this transporter
nor its levels showed any difference when compared to control rats. Furthermore, it
was observed that control rat testes expressed insulin, which was diffusely located
in the cytoplasm of both Leydig cells and early elongated spermatids and concentrated
in a cytoplasmic compartment in the more mature spermatids. Testicular insulin levels
measured by western blot were reduced by more than half in diabetic rats, although
the distribution of the hormone was unchanged. These results indicate that i) insulin
is produced by testicular cells, ii) insulin is depleted by streptozotocin-induced
diabetes, and iii) that insulin depletion and hyperglycemia do not regulate the expression
of GLUT8 in testes. These results also suggest that testicular production of insulin
could play a role in regulating spermatogenesis and/or glucose metabolism in these
organs.
Key words
spermatid - acrosome - streptozotocin - testis
References
Correspondence
jterrado@uch.ceu.es
