OBJECTIVETo establish the testis transplantation model in rats and to study the mechanism of graft injury.

METHODSThe testis orthotopic transplantation model was established using three-cuff method. The animals were divided into 6 groups. Serum levels of testosterone (T), luteining hormone (LH) and follicle-stimulating hormone (FSH) were determined by radioimmunoassay (RIA). Morphology and ultrastructure were examined by light and electron microscopy. Expression of Glial cell line-derived neurotrophic factor (GDNF) mRNA was studied by reverse-transcription polymerase chain reaction (RT-PCR) technique.

RESULTOn the 7th day postoperatively, the allotransplanted testes showed perivascular massive infiltration of lymphocytes and polymorphonuclear neutrophil (PMN) and reduced number of the sertoli cells under light microscopy. It also showed the broken blood-testis barrier, the atrophy of the sertoli cells and spermatogenic cells arranged in disorder under electron microscopy. The decline of serum T level and the increase of serum LH and FSH levels were similar to those found in bilateral castrates. The levels of GDNFmRNA expression were lower than those in normal controls. On 14th day postoperatively, the spermatogenesis of allotransplanted testes was still not recovered and the expression of GDNFmRNA declined further.

CONCLUSIONThe atrophy and reduced number of the sertoli cells and the breakage of the close connection probably are the main causes of dysfunction of spermatogenesis. The decline of GDNFmRNA expression is in accordance with the dysfunction of the sertoli cells and the spermatogenesis.