The of Histopathology of the Testis in Short-Term Toxicology Testing Protocols

Abstract

A reexamination of methodology employed for histopathological evaluation of the testis is currently underway in light of changing and upgraded regulatory requirements/guidelines. With the current general trend toward shortening of testing protocols it will be imperative to change the way the testis is examined. Although testis cells are exposed to a toxicant, usually only some will be affected, and the effect seen upon histological examination is dependent on a variety of factors that are considered herein. Histopathology must be more sensitive than in the past for the detection of treatment-related effects. To improve the sensitivity of this endpoint, it is necessary to obtain better quality tissue for the histopathologist to examine and to have histopathologists well trained in evaluation of the testis. Quantitation of testis germ-cell types is fundamentally important to provide objective information for risk assessment analysis, either to show that the tissue is normal or to show the degree to which spermatogenesis is depressed