This paper is the first version of a Japanese glossary of terms for structural developmental abnormalities in laboratory animals, mainly rats, mice and rabbits. This is a translation of the glossary entitled Terminology of Developmental Abnormalities in Common Laboratory Mammals that was edited by the International Federation of Teratology Societies (IFTS) Committee on International Harmonization of Nomenclature in Developmental Toxicology (IFTS glossary). The purpose of the present Japanese glossary is to provide a common vocabulary, terms and definitions in the description of abnormalities observed in reproductive and developmental toxicity studies. The glossary contains 868 observations, synonyms, related terms, definitions of the abnormalities and non‐preferred terms for external, visceral and skeletal abnormalities in fetuses or neonates of laboratory animals. Modifying terms used repeatedly in the glossary (e. g., absent, atresia) are listed separately in Appendix A, and syndrome names that are generally known are listed in Appendix B. Translation was made into Japanese based on the following: 1) Observations are translated in order of organ/finding (e. g., thymus/absent, maxilla/fused) with exception of the terms in common use, 2) Words are appended where appropriate, when literal translation does not provide an adequate description, 3) A supplementary explanation is appended as an “annotation”, where appropriate, 4) Among the synonyms or related terms, the terms listed in Appendix A or the same Japanese translations as the observations are not described repeatedly, and 5) Non‐preferred terms are not literally translated, and only those terms which are considered as adequate as Japanese are described. Suggestions, questions, and additions are welcomed on the Japanese terms and translations in the glossary. Revisions of the Japanese glossary are planned based on the comments received.

Parameters of male reproductive toxicity of ethinylestradiol were assessed by conducting a mating test, sperm assay, organ weight determination and histopathological examination. Male Sprague Dawley rats were orally administered 0.1, 0.3, 3 or 10 mg/kg/day ethinylestradiol for 4 weeks prior to mating. Body weight gain and food consumption were suppressed in all treated groups. Reproductive ability of the 3 and 10 mg/kg/day males disappeared. Slightly low copulation indices were observed in the 0.1 and 0.3 mg/kg/day groups, although fertility indices were not affected. Sperm could hardly be found in the epididymis of 3 and 10 mg/kg/day males. Sperm counts were also decreased in the other treated groups, but sperm motility was not affected. Decreased absolute and/or relative weights of testes, epididymides, prostate and seminal vesicles were observed in all treated groups along with testis, epididymis, seminal vesicle and prostate atrophy, and degenerative changes of spermatocytes, spermatids, Sertoli cells and Leydig cells. These results suggest that sperm quantification and histopathological assessment are more appropriate for assessing male reproductive toxicity of ethinylestradiol than performance of copulation and fertility tests.

No abstract

The Japanese Behavioral Teratology Meeting, a satellite meeting of the Japanese Teratology Society, proposed a core battery of tests to detect behavioral teratogens in animals in 1992. The core battery consists of examining maternal body weight, offspring weight, external anomalies, viability, preweaning landmarks of physical development (pinna, incisor and eyelids), preweaning reflex tests (surface righting, negative geotaxis and mid‐air righting), an open‐field test at 5 weeks of age, a water‐filled multiple T‐maze (Biel‐type water maze) test at 6 weeks, a shuttlebox test at 7 weeks and brain weight at termination on postnatal day 56. In order to evaluate the detectability of behavioral dysfunction in rat offspring by this core battery, the first collaborative study was carried out in 1993 using phenytoin. The present, second collaborative study using retinoic acid (RA) was performed in twenty‐eight laboratories to further evaluate the proposed core test battery. Pregnant SD rats received 5 mg/kg RA orally from days 14 to 16 of gestation, and postnatal development of their offspring was evaluated. The effects of RA on offspring were detected as lower viability, increased incidence of minor anomalies in the paw and nail, delayed pinna detachment, negative geotaxis and air righting, and less frequent rearing and grooming behaviors in the open‐field test. However, no effects were observed in the Biel‐type maze and shuttlebox tests. These results suggest that our proposed core battery of tests is useful as a screening method to detect postnatal development disorders, including behavioral dysfunction, in SD rat offspring exposed to RA in utero.