Effects of an
antioestrogen (MER-25) on sexual and mammary gland morphogenesis of the mouse fetus
Ch. Jean-Faucher, M.
Berger, M. de Turckheim, G. Veyssi\l=e`\reand Cl. Jean
Physiologie Comparée et Endocrinologie, Université de Clermont II, Complexe Scientifique des Cézeaux, B.P. 45, 63170 Aubière, France The role of fetal androgens in the sexual and mammary differentiation of rodents has been investigated by many methods, including radio-destruction of the fetal testis (see Raynaud, 1969) and the administration of antiandrogens, especially cyproterone acetate (Elger & Neumann, 1966; Jost, 1972; Veyssi\l=e`\re,Jean & Jean, 1974). Antioestrogens, however, have not been used in this type of study and we have therefore determined the effects of an antioestrogen (MER-25: Terenius & Ljungkvist, 1972) on the development of the genital and mammary anlagen of the mouse fetus. Swiss strain mice received subcutaneous injections of 5 mg ethamoxytriphetol (MER-25 : Merrell National Laboratories)/day from the 13th to the 18th day of gestation. All fetuses were delivered on Day 19 by Caesarean section, weighed and fixed for histological examination. The genital apparatus and the two pairs of inguinal mammary anlagen were studied from serial sections. The volume of the first pair was determined by planimetrie measurements on camera lucida drawings of all sections. Twenty fetuses, 12 female and 8 male, were studied and compared with 10 male and 10 female control fetuses of the same age. The body weight of control fetuses was not significantly different from that of the experimental fetuses (1104 ± 39 (S.E.M.) mg and 1097 ± 28 mg respectively) and MER-25 clearly does not modify body growth. The antioestrogen did, however, modify the morphology and the volume of the mam¬ mary gland anlagen of females. In the control females, an anläge was composed of a mam¬ mary cord attached to the epidermis and surrounded by an annular epidermal invagination which marks the limit of the future nipple (PL 1, Fig. 1). The differentiation of the nipple was completely inhibited by MER-25 (PL 1, Fig. 2), leading to a generalized athelia which affected all 48 rudiments studied. In spite of the appearance shown in PL 1, Figs 1 and 2 there was no particular development of the mesenchyme adjacent to the primary cord. The volume of the first inguinal mammary cord was inhibited in the fetuses of treated females, being 30-7 ± 2-2 10-4 mm3 in control fetuses and 23·9 ± 1-3 10~* mm3 in experimental fetuses. This difference of 22-1 % is statistically significant (0001
antioestrogen (MER-25) on sexual and mammary gland morphogenesis of the mouse fetus
Ch. Jean-Faucher, M.
Berger, M. de Turckheim, G. Veyssi\l=e`\reand Cl. Jean
Physiologie Comparée et Endocrinologie, Université de Clermont II, Complexe Scientifique des Cézeaux, B.P. 45, 63170 Aubière, France The role of fetal androgens in the sexual and mammary differentiation of rodents has been investigated by many methods, including radio-destruction of the fetal testis (see Raynaud, 1969) and the administration of antiandrogens, especially cyproterone acetate (Elger & Neumann, 1966; Jost, 1972; Veyssi\l=e`\re,Jean & Jean, 1974). Antioestrogens, however, have not been used in this type of study and we have therefore determined the effects of an antioestrogen (MER-25: Terenius & Ljungkvist, 1972) on the development of the genital and mammary anlagen of the mouse fetus. Swiss strain mice received subcutaneous injections of 5 mg ethamoxytriphetol (MER-25 : Merrell National Laboratories)/day from the 13th to the 18th day of gestation. All fetuses were delivered on Day 19 by Caesarean section, weighed and fixed for histological examination. The genital apparatus and the two pairs of inguinal mammary anlagen were studied from serial sections. The volume of the first pair was determined by planimetrie measurements on camera lucida drawings of all sections. Twenty fetuses, 12 female and 8 male, were studied and compared with 10 male and 10 female control fetuses of the same age. The body weight of control fetuses was not significantly different from that of the experimental fetuses (1104 ± 39 (S.E.M.) mg and 1097 ± 28 mg respectively) and MER-25 clearly does not modify body growth. The antioestrogen did, however, modify the morphology and the volume of the mam¬ mary gland anlagen of females. In the control females, an anläge was composed of a mam¬ mary cord attached to the epidermis and surrounded by an annular epidermal invagination which marks the limit of the future nipple (PL 1, Fig. 1). The differentiation of the nipple was completely inhibited by MER-25 (PL 1, Fig. 2), leading to a generalized athelia which affected all 48 rudiments studied. In spite of the appearance shown in PL 1, Figs 1 and 2 there was no particular development of the mesenchyme adjacent to the primary cord. The volume of the first inguinal mammary cord was inhibited in the fetuses of treated females, being 30-7 ± 2-2 10-4 mm3 in control fetuses and 23·9 ± 1-3 10~* mm3 in experimental fetuses. This difference of 22-1 % is statistically significant (0001
