GB/T 35525-2017Chemicals—Extended one-generation reproductive toxicity study (English PDF)

3.1

Extended Primary Reproductive Toxicity The primary purpose of the test is to evaluate the special stages of life (not included in other toxicity studies) and

Test the possible effects of chemical exposure before and after birth. For the end of breeding, as a first step, repeat dose exposure test (including breeding /

Developmental Toxicity Screening Tests, such as Guideline 422) [2] or short-term endocrine disruptor screening tests (eg Uterine Proliferation Test Guideline Document 440,

Hershberger's Test Guideline Document 441) [3-4] can be used to detect effects on male and female reproductive organs including male spermatogenesis (testis

Pelvic histopathology), female estrus cycle, number of follicles/oocyte maturation and ovarian integrity (histology). Expanded generation reproductive toxicity test

The test requires the testing of reproductive endpoints for the interaction of female-male, female-embryo, female-offspring/sexual maturity subfamilies (F1) [5].

3.2

This test assesses the effect of chemicals on development before and after birth, as well as the comprehensiveness of young and adult offspring of pregnant and nursing mothers and their offspring

Systemic toxicity. Detailed examination of important developmental endpoints, such as offspring viability, newborn offspring health, developmental status at birth, pre-adult body

The development of somatic and functional genes facilitates the identification of specific target organs of offspring. In addition, the test may provide and/or confirm that the test substance is specific to adult males and females

Information on the effects of sexual reproductive system integrity and reproductive behavior. Specific indicators are as follows. gonadal function, estrus cycle, epididymal maturation, mating

Behavior, pregnancy, pregnancy, childbirth and breastfeeding, but not limited to the above indicators, while from neurodevelopmental toxicity and immune developmental toxicity evaluation obtained

The information can be used to assess the potential impact of the test substance on such systems. The above experimental data can be used to determine unobservable end points for various observations (NOAEL), the lowest observed dose (LOAEL) and/or baseline dose for the lesion,

The effect detected in a quantitative exposure test, or as a basis for subsequent testing.

3.3

The extended generation reproductive toxicity test procedure is shown in Figure 1. Groups of sexually mature male and female animals are continued in progressive doses

Toxicity. The parental (P) was exposed before mating (at least 2 weeks) and mating (2 weeks). The male parent continues to infect at least the offspring (F1 generation) milk. Male for at least 10 weeks. If you need to study the impact on reproduction, you can extend the exposure time. Parental female from gestation and breastfeeding

Period continued exposure until its offspring offspring (that is, 8 weeks to 10 weeks). F1 generation from weaning to adulthood continued exposure. If you evaluate the second generation (F2 generation) [1], F1 generation should be maintained until F2 weaning or end of the trial.

3.4

All animals were subjected to clinical observation and pathological examination to determine toxic signs, especially male and female reproductive system integrity and complexity

Proliferation and the health, growth, development and function of offspring. After weaning, F1 generation is assigned to specific subgroups for further observation, including sex

Mature, reproductive organ integrity and reproductive function, nerve and behavioral endpoints, and immune function.