OBJECTIVETo observe the effects of different ways in repairing scrotum of pigs with full-thickness burn on spermatogenesis of testis.

METHODSTwenty male Guizhou miniature pigs were divided into normal control (NC), natural-healing (NH), flap-repairing (FR), and skin-grafting (SG) groups according to the random number table, with 5 pigs in each group. Pigs in NC group were not subjected to any injury. Scrotum of pigs in the latter three groups were inflicted with full-thickness burn. Wounds in NH group healed naturally. Wounds in FR group were repaired with inguinal region flap, and those in SG group with full-thickness skin from lower abdomen. Appearance of scrotum in the latter three groups was observed right after injury, and three months post injury or surgery (PIM or PSM). Specimens of testes of pigs in the latter three groups were obtained in PIM or PSM 3 to detect apoptosis of spermatogenic cells with TUNEL, and bcl-2 protein expression with immunohistochemistry. The same indexes were observed and determined in pigs of NC group. Data were processed with one-way analysis of variance and LSD test.

RESULTS(1) Scrotum of pigs in NC group had skin folds with contraction function. Scrotum of pigs became hard with a leathery appearance right after burn in the other three groups. In PIM or PSM 3, wounds of pigs in NH group healed with scar, and the testes were squeezed into inguinal region. Scrotal skin of pigs in FR group was thick with testes in the scrotum, and that of pigs in SG group was thin with testes in the scrotum. (2) Spermatogenic cells in each level in NC group were arranged regularly, with few apoptotic spermatocytes and spermatoblasts. In NH, FR, and SG groups, seminiferous epithelium was thinner with most of the spermatogenic cells showing apoptosis, and they were mainly spermatogonia and spermatocytes. Apoptotic index of spermatogenic cells in NH, FR, SG, and NC groups was respectively (46.3 ± 3.3)%, (40.9 ± 3.5)%, (20.6 ± 2.3)%, (7.5 ± 1.9)%, and the difference among them was statistically significant (F = 405.65, P < 0.01). There were significant statistical differences among the former three groups (with P values below 0.01). (3) bcl-2 protein expression in NH, FR, SG, and NC groups was respectively (52 ± 5)%, (53 ± 4)%, (64 ± 5)%, (75 ± 5)%, and the difference among them was statistically significant (F = 56.63, P < 0.01). There was no significant statistical difference in bcl-2 expression between NH group and FR group (P = 0.66), and it was lower in both groups as compared with SG group (with P values below 0.01).

CONCLUSIONSEither scar healing, flap transplantation, or SG in repairing scrotum with full-thickness burn in pigs inhibits spermatogenesis, but repair with SG produces less deleterious effect on the testis.