EFFECT OF CRYPTORCHIDISM ON TESTICULAR HISTOLOGY IN A NATURALLY CRYPTORCHID ANIMAL-MODEL

Purpose: To determine the effect of naturally occurring cryptorchidism on testicular histology in both the cryptorchid and normally descende d testis from birth to adulthood using the LE/ORL rat model. Materials and Methods: Testicular hist;ology was assessed using established mor phometric measures in bilaterally descended (ED), unilaterally descend ed (UD), bilaterally cryptorchid (BC) and unilaterally cryptorchid (UC ) testis at days 15, 22, 30, 45 and 60 of age. Testicular mass was als o measured at these times, Results: Changes in testicular histology in the BC and UC testes were not noted on or prior to day 30 of age. Sig nificant changes were noted by day 45 of age and continued into adulth ood at day 60 of age. There were no histological abnormalities noted i n the UD and BD,stoups. Conclusions: Since histological changes seen i n this animal model occur after the time of testicular descent (day 28 of age), we hypothesize that these changes are due to an abnormal ana tomical position of the testis as opposed to an inherent testicular de fect in the LE/ORL rat. This hypothesis is supported by the fact that no histological differences were noted between the scrotal testes of u nilaterally cryptorchid animals and bilaterally descended control anim als.