Expression of vascular endothelial growth factor (VEGF) and factor VIII in the gilt placenta and its relation to fetal development.

Vascular endothelial growth factor (VEGF) and von Willebrand factor (Factor VIII) are important components involved in the regulation of vascular development and identification of endothelial cells in many tissues. This study aimed to evaluate the presence of these substances in the placenta of pig fetuses located in different uterine regions and at different gestational ages and correlate them with fetal development. One hundred seventy-five pig fetuses from fifteen gilts slaughtered at 50, 80 and 106 days of pregnancy were used. Each uterine horn was divided into three segments, the apex, base and middle region, and also into left and right sides. The fetuses were sexed before determining their weight and anatomical measurements. The weights of the placentas were obtained for the calculation of placental efficiency, and VEGF and factor VIII were determined by immunohistochemistry. There was no significant interaction between gestational age, uterine segment or side and fetal sex in any of the variables studied. Higher VEGF and factor VIII concentrations were found at 80 and 105 days of pregnancy, and there was no significant difference between the right and left sides of the uterus, uterine segments or fetal sex. Positive correlations between VEGF and fetal weights were observed at 80 and 105 days of pregnancy, whereas factor VIII showed positive correlations with the weight and length of fetuses and placental weight and efficiency throughout pregnancy. It was concluded that VEGF and factor VIII are important growth factors associated with fetal development in pigs and are identified in all uterine segments. The concentration of these substances increases until the middle third of pregnancy which suggests that most of the uterine vascular development occurs before this stage.

Vascularization of broad ligament of uterus and its relationship with fetal and placental development in gilts.

The objective of this study was to evaluate the influence of vascular architecture of broad ligament of the uterus on fetal and placental development in gilts. Fifteen gilts DB-90 (DanBred) were divided into three groups according to gestational age at slaughter (50, 80, and 106 days). After slaughter, fetuses and placentas were collected, weighed, and measured. The uterine arterial system was detached by latex repletion for quantification of the number and diameter of the terminal vessels in different regions of the uterine horns (apex, middle region, and base). Fetal and placental measurements were statistically analyzed and correlated with the number and diameter of arteries in each uterine segment. No correlation was observed (P > 0.10) between the number and diameter of arteries destined to the uterus with the number or weight of fetuses or placental weight in any gestational group. It was observed (P < 0.05) that more vessels destined to the medium region of the uterine horns, independent of the gestational age or uterus side. At the 80th day of gestation, fetuses located at the base of the uterus have (P < 0.05) smaller cephalic and thoracic perimeters. It was concluded that there were differences in vascularization of broad ligament that irrigates the different uterine segments, but this was not sufficient to influence the development of fetuses in gilts. The middle region of the uterine horns was the segment with a greater number of vessels, regardless of gestational age.