Influence of intrauterine blood supply on cranial growth and sexual dimorphism at birth.
Many experimental studies of the effects of placental blood flow on growth exist. Nevertheless, few of them deal with the relationship between impaired uterine blood supply, and cranial growth and sex differentiation. The object of the present study was to investigate the impact of intrauterine growth retardation (IUGR) on sexual cranial dimorphism in the newborn rat. Three experimental groups were employed: (a) control; (b) operated (IUGR), in which both uterine vessels were partially bent in the 15th day of gestation; and (c) sham-operated, identical to (b) but without vessel bending. At birth, pups were weighed, and their bodies and craniums, measured. In the cases of asymmetric distributions, data were logarithmically transformed. A multi-way analysis of variance (ANOVA) and LSD post-hoc tests were used to find out differences between experimental groups and sex. Controls had significant sex differences in body and cranial variables. The prenatal growth of IUGR pups was significantly inhibited. Body and facial variables were more affected than the neurocranial ones. Undernutrition produced body and cranial size changes. Since IUGR affected male more than female growth, sex dimorphism was clearly reduced in all variables which were dimorphic in controls.
Oyhenart
E E
EE
Centro de Investigaciones en Genética Básica y Aplicada, Facultad de Ciencias Veterniarias, Universidad Nacional de La Plata, Argentina.
Muñe
M C
MC
Pucciarelli
H M
HM
D000818:Animals; D000831:Animals, Newborn; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics; D012886:Skull / Q000254:growth & development*; D014599:Uterus / Q000098:blood supply*