[Impact of the reconstruction of the scrotum with third-degree burns on spermatogenic function: experimental study of...

To explore the effects of different methods of scrotal reconstruction on the apoptosis of spermatogenic cells and expression of the bcl-2 protein in patients with third-degree scrotal burns.

Forty male and 24 female 2-month-old Guizhou mini-pigs were used in this study, the former equally randomized to groups I (normal control), II (natural healing), III (skin grafting) and IV (skin flap grafting). Ten months after the establishment of the model of third-degree burns, 6 male pigs from each group were paired with the female pigs and fed for 3 weeks. Then the female pigs were fed for another 4 months, followed by observation of their reproductivity. At 12 months, the bilateral testes were taken from the male pigs for detection of the apoptosis index of spermatogenic cells by TUNEL and determination of the expression of the bcl-2 protein by immunohistochemistry. The data obtained were subjected to single factor analysis of variance.

The apoptosis indexes of spermatogenic cells were (7.07 +/- 3.5), (40.34 +/- 4.85), (15.14 +/- 1.36) and (39.29 +/- 5.73)% in groups I , II, III and IV, respectively, significantly higher in groups II , III and IV than in I (P<0.05), with statistically significant differences between group III and groups II and IV (P<0.05) but not between II and IV (P>0.05). The expression rates of the bcl-2 protein were (75.07 +/- 3.74), (54.93 +/- 4.03), (66.85 +/- 3.06) and (53.33 +/- 5.22)% in groups I, II, III, and IV, respectively, remarkably higher in I than in the other three (P<0.05), with significant differences between group III and groups II and IV (P<0.05) but not between II and IV (P>0.05). Pregnancies were found in all the female pigs of group I with 10.0 +/- 1.18 newborns and in 4 of group III with 9.92 +/- 1.31 newborns, but in none of groups II and IV, with significant differences between group I and the other three (P<0.05) as well as between group III and groups II and IV (P<0.05), but not between II and IV (P>0.05).

All the three methods of reconstruction for the scrotum with third-degree burns can suppress spermatogenic function, increase the apoptosis of spermatogenic cells and decrease the expression of the bcl-2 protein, among which, skin grafting least affects spermatogenic function.