Radio-protective effect of vitamin E on spermatogenesis in mice exposed to gamma-irradiation: a flow cytometric study.
OBJECTIVE
To investigate the effect of vitamin E on the radioprotection of spermatogenesis and chromatin condensation of spermatozoa during passage through the epididymis in mice exposed to irradiation.


METHODS
Adult outbred male ICR mice were orally administered natural vitamin E (VE, D-alpha-tocopheryl acetate) at 400 IU/kg for 7 days before exposure to 1 Gy of gamma-irradiation. The animals were sacrificed at day 1, 7, 14, 21, 28, 35 and 70 post-irradiation (IR) and the percentage of testicular germ cells and epididymal sperm chromatin condensation was analyzed using flow cytometry.


RESULTS
Serum D-alpha-tocopheryl acetate levels were 47.4+/-3.2 microg/dL in the treated group, yet it could not be detected in the control group. The testicular weight of irradiated mice pretreated with VE+IR was significantly (P<0.05) higher than that of those without VE treatment (IR) at day 14 and 21 post-irradiation. The percentage of primary spermatocytes (4C) in the VE+IR group was comparable to the controls but significantly (P<0.05) higher than those in the IR group from day 7 to 35 post-irradiation. The percentage of round spermatids (1C) in the VE+IR group was also significantly (P<0.05) higher than those in the IR group at day 28 post-irradiation. The primary spermatocytes : spermatogonia ratio in the IR group was significantly (P<0.05) declined at day 7 to 35 post-irradiation when compared to the VE+IR and control groups. The round spermatid : spermatogonia ratio in the VE+IR group was significantly (P<0.05) higher than that of the IR group at day 14 and 28 post-irradiation. The chromatin condensation of epididymal spermatozoa measured by propidium iodide uptake was not affected by 1 Gy of gamma-irradiation.


CONCLUSIONS
The administration of VE prior to irradiation protects spermatogenic cells from radiation.
Songthaveesin
C
C
Department of Radiology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand.
Saikhun
J
J
Kitiyanant
Y
Y
Pavasuthipaisit
K
K
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002843:Chromatin / Q000187:drug effects / Q000528:radiation effects; D005434:Flow Cytometry; D005720:Gamma Rays; D005854:Germ Cells / Q000187:drug effects; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009929:Organ Size / Q000187:drug effects; D011419:Propidium; D011837:Radiation-Protective Agents; D013087:Spermatids / Q000187:drug effects / Q000528:radiation effects; D013091:Spermatogenesis / Q000187:drug effects* / Q000528:radiation effects*; D013737:Testis / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D014810:Vitamin E / Q000097:blood / Q000494:pharmacology*
D000975:Antioxidants; D002843:Chromatin; D011837:Radiation-Protective Agents; D014810:Vitamin E; D011419:Propidium