Histological and stereological studies on Leydig cells in the testes of Gallus domesticus from pre-hatching to sexual maturity.

The present study was aimed at evaluating the sequence of the histological and quantitative changes that occur in diverse components of the interstitial tissue, as well as the variations in the number and volume of Leydig cells of the testes of Gallus domesticus from 8-day-old embryo to 28-week-old chickens. Results indicate an increase in total volume of all components of the interstitial tissue: Leydig cells, blood vessels, and interstitium of chicken testes with advancing development. The proportion of each component differs markedly according to the age of the animal. Data indicate that Leydig cells are present in the chicken testes from pre-hatching to sexual maturity, and show an increase in the total volume, number per testis, and individual cell volume along the age of the animal. Values of P<0.05 were considered statistically significant. The results indicate that the total volume of Leydig cells is the dominant component of the interstitial tissue in the testes of 6-week-old chickens, but in testes of chicken embryos correspond to the lowest percentage of interstitial tissue. Results also reveal that hyperplasia is more important than cell hypertrophy in the increase of the total volume of Leydig cells during advancing development.