[Relationship between germ cell apoptosis and Sertoli cell vimentin in prepubertal rats induced by local exposure to heat].
OBJECTIVE
To explore the relationship between germ cell apoptosis and the expression as well as the distribution of Sertoli cell vimentin induced by local exposure to heat.


METHODS
Local short-term exposure of prepubertal male rats testis to heat (43 degrees C for 15 min). Histochemical method was used to observe morphological characteristics of seminiferous tubule. The distribution and expression of Sertoli cell cytoskeletons were analyzed by immunohistochemistry and germ cell apoptosis was evaluated by TUNEL technique at different hour-intervals.


RESULTS
After 2 h and 4 h heat exposure, the disattachment phenomenon between Sertoli cell and spermatogonia occurred. Spermatogonia arranged in disorder and displaced away from the basement membrane of seminiferous tubules. Immunohistochemical staining showed that vimentin positive staining was seen radiating from the Sertoli cell perinuclear region with apical "spoke-like" pattern in controls. There was an intense vimentin immunoreactivity surrounding Sertoli cell nuclei along with the collapse of the apical extensions in 2 h group, but no significant difference compared with the controls. The expressions of vimentin in 12 h and 24 h groups were higher than those of the controls (P <0.01), respectively. TUNEL showed that incidence of apoptosis was observed to increases markedly in 12 h and 24 h groups, but it was found that the incidences of apoptotic events were decreased in these two groups compared with the controls.


CONCLUSIONS
The changes of expression and distribution of Sertoli cell vimentin filaments correlate with the increased germ cell apoptosis. Local heat may disrupt spermatogenesis by injuring Sertoli cell directly.
Zhang
Ji-qiang
JQ
Faculty of Physiology, Medical College of Shantou University, Guangdong, China. g_jqzhang@126.com
Qin
Da-nian
DN
Cui
Hai-yan
HY
D000818:Animals; D017209:Apoptosis; D006358:Hot Temperature; D020287:In Situ Nick-End Labeling; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012708:Sertoli Cells / Q000378:metabolism*; D013094:Spermatozoa / Q000473:pathology*; D014746:Vimentin / Q000096:biosynthesis*
D014746:Vimentin