Detection of alterations in testicular and epididymal function in laboratory animals
The potential impact of an agent altering male reproductive function is greater for humans than for animals. Consequently, it is essential that sensitive criteria be used to look for effects on a multiplicity of target sites when an agent is evaluated using an animal model. No animal model has reproductive characteristics similar to those of humans, but this does not negate the validity of using animal models. Classic methodologies for reproductive toxicology are limited by the approaches used for subjective evaluation of testicular histology and use of natural mating for fertility tests. After dosing for an interval at least equal to six times the duration of one cycle of the seminiferous epithelium, sperm from ejaculated semen or the cauda epididymidis can be evaluated for normalacy of morphology or function and should be used for artificial insemination of females to critically evaluate fertility. Normal males of animals models ejaculate a great excess of sperm. Artificial insemination of a critical number of sperm, selected to result in slightly less than maximal fertility for control animals, will maximize the probability of detecting a decrease in fertility if the same critical number of sperm is inseminated for treated animals as for control animals. Testicular function should be evaluated by objective, rather than subjective, criteria. Among the more sensitive criteria of testicular function are the minor diameter of essentially round seminiferous tubules, the ratio of leptotene spermatocytes to Sertoli cells, the corrected numbers of germ cells per seminiferous tubule cross section, and the number of homogenization-resistant spermatids per testis.
- Research Organization:
- Colorado State Univ., Fort Collins, CO (United States)
- OSTI ID:
- 6785399
- Journal Information:
- Environ. Health Perspect.; (United States), Vol. 70
- Country of Publication:
- United States
- Language:
- English
Similar Records
Use of animal models for detecting specific alterations in reproduction
Radiation-induced DNA content variability in mouse sperm
Related Subjects
DRUGS
TOXICITY
TESTES
PHYSIOLOGY
BIOLOGICAL MODELS
FERTILITY
LIFE SPAN
MALES
MAN
MICE
RATS
REPRODUCTION
SPERMATOGENESIS
SPERMATOZOA
ANIMALS
BODY
GAMETES
GAMETOGENESIS
GERM CELLS
GONADS
MALE GENITALS
MAMMALS
ORGANS
PRIMATES
RODENTS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology