Effect of diethylstilbestrol or zeranol on fetal development, gestation duration, and number of offspring in NMRI mice.
OBJECTIVE
To evaluate the effects of diethylstilbestrol (DES) or alpha-zearalanol (zeranol) on fetal development, gestation duration, and number of offspring.


METHODS
Study effects of prenatal administration of DES or zeranol on various pre- and perinatal variables in an experimental group of mice, compared with effects in a control group.


METHODS
Pregnant NMRI mice.


METHODS
Diethylstilbestrol or zeranol (150 mg/kg of body weight) or vehicle (controls) was administered SC to pregnant mice on days 9 and 10 of gestation. Fetuses from pregnant mice of each group were counted and weighed, and their size and head length were recorded. Additional pregnant mice delivered their fetuses naturally, and pups from each group were counted and their sex was determined. At the end of gestation, abortions were evaluated. All data were statistically analyzed.


RESULTS
Mean number of fetuses was significantly lower (P < 0.0001) in DES-treated (4.59 +/- 0.48) than in control mice (8.33 +/- 0.49). Both estrogenic substances significantly reduced fetal size and weight (P < 0.0001), compared with control mice. Diethylstilbestrol significantly increased abortion frequency (P < 0.0001) and gestation duration (P < 0.0001), compared with values for control mice. A reduced number of live pups (P < 0.0001) from pregnant mice administered DES (5.48 +/- 0.38) or zeranol (5.97 +/- 0.49) was observed, compared with control mice (8.52 +/- 0.50), because of reduced number of male offspring (P < 0.0001).


CONCLUSIONS
Diethylstilbestrol or zeranol administered during mid-pregnancy leads to decreased fetal weight and size and lower numbers of male offspring at birth. Likewise, DES induced a significant increase in abortions and gestation duration.
Pérez-Martínez
C
C
Department of Animal Pathology, Animal Medicine, Faculty of Veterinary Science, University of León, Spain.
García-Iglesias
M J
MJ
Bravo-Moral
A M
AM
Ferreras-Estrada
M C
MC
Martínez-Rodríguez
J M
JM
Escudero-Díez
A
A
D000818:Animals; D001724:Birth Weight / Q000187:drug effects; D004054:Diethylstilbestrol / Q000008:administration & dosage / Q000494:pharmacology*; D005314:Embryonic and Fetal Development / Q000187:drug effects*; D004968:Estrogens, Non-Steroidal / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005333:Fetus / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology; D007279:Injections, Subcutaneous; D008098:Litter Size / Q000187:drug effects*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains / Q000196:embryology*; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000662:veterinary; D011270:Pregnancy, Animal / Q000187:drug effects* / Q000502:physiology; D012744:Sex Ratio; D015029:Zeranol / Q000008:administration & dosage / Q000494:pharmacology*
D004968:Estrogens, Non-Steroidal; D004054:Diethylstilbestrol; D015029:Zeranol