Premium
Age‐related changes in the testes of horses
Author(s) -
FUKUDA T.,
KIKUCHI M.,
KUROTAKI T.,
OYAMADA T.,
YOSHIKAWA H.,
YOSHIKAWA T.
Publication year - 2001
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.2746/042516401776767449
Subject(s) - lamina propria , basal lamina , myofibroblast , pathology , fibrosis , biology , atrophy , anatomy , vimentin , immunohistochemistry , ultrastructure , basal (medicine) , epithelium , endocrinology , medicine , insulin
Summary Atrophy of seminiferous tubules and interstitial fibrosis are frequently observed in aged horses. Samples from 8 male Thoroughbreds, age 4–24 years, were subjected to histological, electron microscopical and immunohistochemical examination and statistical analysis. There were statistically significant increases in collagen fibres in the lamina propria of seminiferous tubules and testicular interstitium in 3 horses age 23 and 24 years compared with 5 horses age 4–20 years (P<0.001). Lamina propria surrounding atrophic tubules was thickened by an increase in collagen type IV and elastic fibres and by proliferation of bizarre myoid cells. Basal lamina was also thickened but had decreased reactivity for collagen type IV. Some myoid cells changed morphologically to a swollen and irregular shape and contained abundant cytoplasmic organelles. Laser scanning microscopy revealed that cytoplasmic actin filaments were decreased; the remaining filaments were positive for α‐smooth muscle actin and vimentin, and matrix metalloproteinase‐2 was secreted. These myoid cells transformed into myofibroblasts. The changes are interpreted as evidence of injured structure and function of the lamina propria and basal lamina and may explain the functional decline of the blood‐testis barrier. Myoid cells may play an important role in the progression of testicular fibrosis.