OBJECTIVETo explore the temperature change at the testis surface, apoptosis of spermatogenous cells and the expression of the heat shock protein 70 (HSP70) after scrotal reconstruction with the skin flap.

METHODSWe included 36 healthy New Zealand white rabbits, 24 males and 12 females, in this study, and equally randomized the males into an experimental and a control group. The scrotal of the experimental rabbits were excised and reconstructed with the hypogastric flap, while the controls were left untreated. At the end of the 8th week after surgery, 6 animals were randomly taken from each of the two groups for measurement of the testis surface temperature and testicular biopsy. The apoptosis of spermatogenous cells in the testis tissues was detected by HE staining, and the expression of HSP70 determined by immunohistochemistry and imaging analysis. The other 6 animals exempt from testicular biopsy in each of the experimental and control groups were mated with the female rabbits, and observed for fertility.

RESULTSAt the end of the 8th week after scrotal reconstruction, the testicular surface temperature was (38.1 +/- 0.6) degrees C in the experimental group, significantly higher than (36.0 +/- 0.30) degrees C before surgery (P < 0.05), and the apoptosis index (AI) of the spermatogenous cells was (71.85 +/- 2.7) %, as compared with (7.73 +/- 4.95) % in the control group (P < 0.05). The expression of HSP70 was found mainly in the spermatogenous cells of the experimental group and in the spermatoblasts of the control. A total of 6.0 +/- 1.3 baby rabbits were born in the control group, but none in the experimental group (P < 0.05).

CONCLUSIONThe testicular surface temperature rises after scrotal reconstruction with the hypogastric flap, which increases the apoptosis of spermatogenic cells and causes infertility. HSP70 is involved in protecting spermatogenic cells from apoptosis after scrotal reconstruction.