ABSTRACT
This study was designed to evaluate the ultrastructural testicular changes of experimental exposure
to mega-doses of pyridoxine and to evaluate the impact of duration of exposure on these changes. The
study comprised 15 normal healthy growing male albino rats divided into 3 equal groups (n=5):
control group: did not receive medications, Group I: received intraperitoneal injection of pyridoxine in
dose of 500mWkg, day for 2 weeks and for 6 weeks in group II; animals were sacrificed about 24 hours
after the last administration. Both testes were removed testicular tissue was prepared for
ultrastruchiral examination under Joel 100 CX transmission electron microscope. The setniniferous
tubules of rats treated for 2 weeks showed degenerative changes in the developing spermatogenic cells
and Sertoli cells. Some mitochondria are swollen and have large vacuoles within their compartments.
No changes occur in the Golgi apparatus. The nucleus is still having the homogenously dust like
chromatin but more accumulation of chromatin particles and clumps occurs against the nuclear
membrane. Primary spermatocytes showed reduction in sizes, remarkable flattening of both nuclei
and cytoplasm. The flattened nuclei are still covered by a double membranes nuclear envelope.
Sperrnatids damage occurs in the form of appearance of some vacuoles within the acrosornal material
while the head cap becomes very thin but still covering the whole acrosome. Much more damaging
effects were found in either the characteristic features or the morphology of the mitochondria. The
Sertoli cells showed many intercellular vacuoles of variable sizes, large amounts of lysosome are
present within the cytoplasm of Sertoli celL These histological changes were exaggerated after
treatment for 6 weeks. It could be concluded that mega-doses of pyridoxine administered for long
period have a direct toxic effect of testicular ultrastructure and have harmful impact on male fertility |
