Yonago Acta medica 1997;40:79–89
A Novel Mechanism to Explain the Detrimental Effects of Left Cryptorchidism on Right Testicular Functions
Kouji Ono and Nikolaos Sofikitis
Department of Urology, Faculty of Medicine, Tottori University, Yonago 683, Japan
The effect of unilateral cryptorchidism on ipsilateral testicular function has been well studied in human and experimental animals. However the effect of unilateral cryptorchidism on contralateral testicular function has remained unclear. To evaluate the effect of left cryptorchidism on right testicular function, an experimental model was created in 2 groups of immature male rats (group A, 19 rats; and group C, 7 rats). Seven male rats of the same age were sham-operated (groups B and D). Twenty-eight days after the operation, bilateral epididymal caudal sperm content and motility, bilateral testicular weight, bilateral epididymal caudal weight, seminal vesicular weight, right testicular versus intra-abdominal temperature difference (RDT), fertility rate, right epididymal caudal sperm acrosin profile, testosterone response to human chorionic gonadotropin stimulation and mean seminiferous tubular diameters of bilateral testes were tested. They were significantly lower in group A than in group B (Student’s t-test; P < 0.05). In contrast, the concentrations of serum luteinizing hormone and follicle stimulating hormone were significantly higher in group A than in group B (Student’s t-test; P < 0.05). Four months after the operation, right testicular blood flow was significantly higher in group C than in group D (Student’s t-test; P < 0.05). These results indicate a bilateral Leydig cell secretory deficiency in rats with unilateral cryptorchidism results in the impaired spermatogenic process and epididymal sperm maturation process. This effect may be explained by the elevation of the right testicular temperature as a result of an increase in testicular blood flow.
Key words: cryptorchidism; fertility; testicular function; testicular blood flow; testicular temperature
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