Age-related change in numbers of other interstitial cells in testes of adult men: evidence bearing on the fate of Leydig cells lost with increasing age

Abstract

The number of Leydig cells in the adult human testis declines as a function of increasing age, but whether these cells disappear by transforming into another cell type or by undergoing death and dissolution has not been resolved. This question was addressed in 30 men between 20 and 76 years of age who were known as a group to have experienced significant age-related loss of Leydig cells. If the loss of Leydig cells resulted from transformation into another cell type, other testicular interstitial cells in these men should have increased with age. Testes obtained at autopsy were perfused with glutaraldehyde less than 15 h after sudden death due to trauma or heart attack. Numbers of other interstitial cells were determined by quantitative histometric estimation of the proportion of testicular parenchyma occupied by other interstitial cell nuclei of measured average volume. Other interstitial cell nuclei declined significantly with advancing age (rho = -0.41, P less than 0.05). Mean number of other interstitial cell nuclei per individual was significantly reduced in the 15 men 50 yr old or older compared to the 15 younger men (460 +/- 34 million vs. 609 +/- 43 million; P less than 0.05). There was no tendency for individuals with reduced numbers of Leydig cells to have increased numbers of other interstitial cells. These findings argued against the persistence of Leydig cells in aged testes as dedifferentiated mesenchymal elements. Instead, light and electron microscopic observation of testes from these men revealed evidence of Leydig cell degeneration and dissolution.

Immunocytochemical and quantitative study of the tunica albuginea testis in young and ageing men

“…This increase in thickness is probably the result of the diminution in the testicular parenchyma volume; that is, the tunica albuginea covers less testicular surface but maintains its volume. These results agree with the scanty quantitative changes observed in testicular connective tissue with age, except for a decrease in the number of Leydig cells in the testicular interstitium (Neaves et al 1985;Paniagua et al 1987). Age-related changes in testicular volume are principally noted in the seminiferous tubules, which decrease in length and diameter as a consequence of the loss of both germ cells and Sertoli cells, whereas the volume occupied by the testicular interstitium remains unchanged Paniagua et al 1987).…”

Turnover Time of Leydig Cells and Other Interstitial Cells in Testes of Adult Rats

“…The age of the rats used in New Leydig cells were probably formed to replace cells that had died; otherwise the population of Leydig cells would decrease. In some aging mammals the replacement of cells that have died is incomplete, resulting in a decrease in the number of Leydig cells [14].…”

Efficient and Unbiased Tools for Quantitating Leydig and Sertoli Cells in the Testis From Testes Biopsies

“…The total Leydig and Sertoli cell numbers, estimated by use of stereological methods, differed from the results obtained from most previous studies. The estimated total Sertoli cell numbers have been reported to range from 390 to 3700x10 6 and the total Leydig cell number from 400 to 800x10 6 , calculated from twodimensional profile counting (Cortes et al, 1987;Paniagua et al, 1987;Kaler and Neaves, 1978;Neaves et al, 1985). These large ranges may be ascribed to the difficulties in interpretation of results obtained from assumption based designs as previously described (Mendis-Handagama and Ewing, 1990;Mendis-Handagama, 1992).…”