Evaluation of histomorphometric changes in the uterus of prenatal restricted lambs

Abstract

The aim of the study was to describe the histomorphometric characteristics of the uterus of 45-days-old lambs belonging to mothersnutritionally restricted or controls from the second half of gestation.Merino pregnant ewes carrying single fetuses were randomly assigned to restricted (R) or control (C) groups and fed with 75% or125% of metabolic energy requirements from ~80 days to ~140days of gestation, respectively. Uterus samples from Merino female lambs of 45-days-old (n=7 for each group) were evaluated.For the histomorphometric evaluation, 3 cuts of 4 µm thickness ofeach uterine horns were obtained and stained with H-E in order toevaluate the following parameters: height of the luminal epithelium(HLE) and the glandular epithelium (HGE), considering the distancebetween the basal membrane and the apical end of 30 cells ofeach of the epithelia with a magnification of 100x. Glandular density (GDe), the number of glands in 10 fields at 40x magnificationand Glandular area (GA) using the following formula: GA=π×(Axis1)/2×(Axis 2)/2 were evaluated. The axes were the average of tworight-angled diameters in a minimum of 30 glands per section at 100x magnification. Samples were analyzed by two observers. Theresults were analyzed by ANOVA. Data are expressed as mean ±SD. Results were considered significant with P≤0.05. HLE and AGdid not differ between groups (R: 11.73±0.18; 1347.43±36.74 andC: 11.81±0.18; 1277.54±36.74; respectively; P≤0.05). The HGE andGDe were significantly higher for lambs from R than lambs from Cgroup (R: 13.34±0.18; 25.19±0.59; C: 12.86±0.18; 22.32±0.64; respectively; P≤0.05). The pre-natal maternal nutrition could affect thedevelopment of uterine glands in their lambs. In this study, a higherHE and GDe was observed in the uterus of lambs born from nutritional restricted mothers. Future studies are necessary to explainthese results.