Virilizing activities of various steroids in female rat fetuses.

Virilizing effect of testosterone and its metabolites on the urovaginal septum of female fetal rats.

“…It should be noted that the critical time for the fetal virilizing activity of testosterone falls on the 19th day of gestation both in the case of injection into the fetus and in the case of injection into the mother (Kawashima et al, 1977 …”

“Natural” progesterone: information on fetal effects

“…Other studies (Piotrowski, 1968b;Scholer and de Wachter, 1961;Wharton and Scott, 1964;Kawashima et al, 1977;Suchowsky et al, 1967;Foote et al, 1964;Revesz et al, 1960;Lerner et al, 1962) failed to find a virilizing effect of progesterone using either anogenital distance or other related measures. These studies, summarized in Table 3, generally had smaller group sizes and less precise measures of anogenital distance than the two studies demonstrating an effect.…”

“…In guinea pigs treated with 1 mg/day progesterone by subcutaneous (s.c.) injection on gd 18-60, no statistically significant effects on birthweight or gestation length were seen relative to untreated controls (Foote et al, 1964). In their studies of Wistar rats, described below, Kawashima et al (1977) provided only data on urovaginal septum length, with no information on birth weight or litter size.…”

“…Progesterone was not found to virilize mouse genitals in a highly standardized study comparing the virilizing effects of 12 progestagens, including progesterone and nor-testosterone derivatives, as well as 7 testosterone derivatives (Kawashima et al, 1977). The endpoint used was the fetal urovaginal septum length expressed in mm/g body weight.…”

Virilizing effect of methyltestosterone on female descendants in the rat.

“…It has been well known that in the rat, virilization of female offsprings is caused by maternal administration of some synthetic steroids during late pregnancy (Neumann and Junkmann, 1963;Neumann and Kramer, 1964;Suchowsky et al, 1967;Ogawa and Nozawa, 1969;Schultz and Wilson, 1974;Kawashima et al, 1975 and1977). In the adult life of this offspring (the second generation), there are induced consecutive alterations in the reproductive system such as failure of formation of corpora lutea (Turner, 1939;Kobayashi, 1967;Kobayashi, 1970;Swanson and van der Werff ten Bosch, 1965;Saunders, 1967), persistent cornification in the vaginal smear, lowered copulatory response (Kobayashi, 1967;Ogawa and Nozawa, 1969) and so forth.…”