Gross and Microscopic Findings of the Testes Ascended into abdomen During Neonatal and Prepubertal age in Rats

Han, Woong Kyu; Lee, Seung Eon; Han, Sang Won; Choi, Seung Kang; Lee, Tack

Abstract

PURPOSE: Because cryptorchid testes are known to undergo histopathologic changes affecting development, maturation, and tertility, early surgical correction is usually recommended. However there are differing opinions concerning whether retractile testes are affected by similar changes and also whether there is a need for surgical treatment. We aimed to assess the histopathologic changes in retractile testis by studying the changes in testes artificially placed back in the abdomen after they have descended to scrotum in experimental rat models.
MATERIALS AND METHODS
Male Sprague-Dawley rats were divided into 3 groups; a control group(controls), prepubertal ascent group (P) in which testis were placed back intraabdominally by bilateral inguinal canal obstruction at 6 weeks, a neonatal group(N) in which intraabdminal testis was induced by bilateral inguinal canal obstruction at birth. The relative weight of the testis, morphology of the seminiferous tubules including Leydig cells, tubular degeneration phase(TDP), spermatogonia per tubules(S/T), and Sertoli cell index (SCI) of these three groups were analyzed and compared.
RESULTS
The relative weight of testis was significantly decreased in the group of N(0.0016+/-0.001) and P(0.0015+/-0.0002) compared to controls(0.0037+/-0.0002) (p<0.05). The S/T value was also decreased in P(2.05+/-18.2) and N(73.2+/-32.4) when compared to controls (360.2+/-21.3). Similar changes were observed in SCI of both P(64.5+/-6.4) and N (91.2+/-14.2) when compared to controls (227.9+/-31.1). Only minority of N and P showed higher TDP values. However, although statistically insignificant, TDP was increased in both P and N when compared to controls. The Leydig cells in N and P showed cellular distortion and hypertrophy.
CONCLUSIONS
This study demonstrate that prepubertal ascent, similar to that of innate cryptorchid testis, also can induce histopathologic changes such as changes in testicular seminiferous tubule, decrease in the S/T value and decrease in SCI value. Our findings supports that hypothesis that retractile testis may cause histological damage thus surgical correction may also be warranted similar to in case of genuine cryptorchism.