Morphological and immunohistochemical studies in testes of normal and cryptorchid boars

Scrotal (n = 66), inguinal (n = 7) and abdominal (n = 36) testes from pigs differing in age (from 1 day to 4 years) were collected after slaughtering or by castration, fixed in 4% formalin and examined by light microscopy. The expression of vimentin, desmin, alpha-actin and PCNA was detected by immunohistochemical technique. Histologically no differences between scrotal and cryptorchid testes are obvious during the prepubertal period, until the age of 10-12 weeks, but with the onset of puberty degenerative alterations (Sertoli-cell-only morphology, giant cells) in dystopic testes occur. Additionally the differentiation of the interstitial cells is disturbed in abdominal testes resulting in a deviating expression pattern of alpha-actin. The Sertoli cells show different distribution patterns (basal, perinuclear, apical) of vimentin depending on the position of the testis and the age of the animal.