OBJECTIVETo study the mechanism of male infertility caused by varicocele by evaluating the effects of hyperbaric oxygenation (HBO) therapy on the testicular tissue morphology and function of rabbit model with varicocele(VC).

METHODSTwenty-four mature male rabbits were randomly divided into three groups: pseudo-operation, VC model and VC model administered by HBO. Experimental varicocele was induced by partial ligation of the left "lumbotesticular" trunk vein in rabbits. HBO was administered to one of the two groups of VC model rabbits after the operation. Weight and volume of both testes, parameters of seminal fluid, histological changes of testicular tissues, MTDs, TFI, and Sertoli cell index (SI) of seminiferous tubules were studied.

RESULTSThe average weight and volume of the left testes significantly increased in the rabbits treated by HBO. The semen quality was improved, and MTDs increased significantly compared with VC group(P < 0.0001). The testicular tissue morphology became nearly normal in VC + HBO group.

CONCLUSIONS1. Both the structure and spermatogenetic function of testes can be damaged by the presence of varicocele; 2. Chronic ischemia, anoxia and microcircular dysfunction may be the key process and essential factor that make varicocele contributive to testicular damage and spermatogenetic dysfunction; 3. HBO can effectively alleviate, even eliminate, chronic ischemia, anoxia and microcircular dysfunction in testicular tissues with varicocele, and thus protect the structure and functions of testes.