Morphologic Evaluation of Seminiferous Epithelium of the Testis

Reproductive toxicity testing—Methodology

“…Proper fixation (with modified Davidson's fixative for at least 48 hours) and careful trimming, embedding (paraffin), sectioning (5-6 µm), and staining of testicular tissue (91,92) improves the quality of the histological evaluation of spermatogenesis. Care must be taken to minimize the compression of the testes during tissue dissection, as it can result in artifactual damage to the testes (such as sloughing of germ cells from the seminiferous epithelium).…”

Correspondence

“…There are significant limitations associated with the use of each of these histological procedures in male reproductive toxicity studies which 2^ahid et al failed to address. First, it is well known that immersion fixatives such as Bouin's produce a variable amount of protein coagulation, which manifests as a "grain" in the cells (Chapin, 1988). It possible that this artifact was misinterpreted by Zahid et al as evidence of tubular and/or spermatogenic pathology.…”

“…It possible that this artifact was misinterpreted by Zahid et al as evidence of tubular and/or spermatogenic pathology. Second, when sections of testis are embedded in paraffin, significant shrinkage of the tissue occurs (Chapin, 1988 (Chapin, 1988). Finally, the stage of spermatogenesis for any given tubule is based, in part, on the changes in the acrosome and nucleus of the spermatids present in that tubule.…”

“…Finally, the stage of spermatogenesis for any given tubule is based, in part, on the changes in the acrosome and nucleus of the spermatids present in that tubule. Thus, to minimize uncertainty when assigning testicular lesions to particular spermatogenic stages, the acrosome of the spermatids should be stained with periodic acid-Schiff's reagent (PAS) followed by hematoxylin (Chapin, 1988 and Cr(VI) significantly effected spermatogenesis, sperm count and sperm morphology in the six dosed groups (a multisample hypothesis). However, the t statistic (and its associated critical value) are only designed to test whether two sample statistics (the means of two sample populations) are likely to have originated from the same population.…”

“…As indicated above, however, Zahid et al used eosin, which does not stain the acrosome of developing spermatids(Chapin, 1988). Therefore, it is doubtful that details Downloaded by [Ohio State University Libraries] at 08:21 25 March 2015 concerning spermatogenic stages and tubular pathology reported in Tables 2 and 3 of the Zahid et al study can be accurately and reproducibly resolved using the histochemical methods employed by Zahid et al Consequently, it is difficult to determine whether effects actually occurred at any dose level.…”