Effects of water and lipid phases of meconium on contractility of mesenteric artery

Introduction and Aim: Clinical and experimental studies on gastroschisis showed that fetus releases meconium into amniotic fluid and that meconium causes intestinal injury in the fetuses with gastroschisis. The mechanism of injury is not clear. In-vivo and in-vitro studies showed that meconium has an vasoconstrictor effect on umblical vessels and Doppler flow studies of fetuses with gastroschisis showed the differences in mesenteric arteries (MA) supplying the intestines. Meconium has the potential of ischemia on MA with vasoconstriction. In a recent experimental study it is reviewed that meconium causes vasoconstriction on MA of chicken embryos. Which substances in meconium causes this effect is not shown. We extracted water and lipid phases of meconium in this study. We aimed to determine each effect of the water and lipid phases of meconium on contractility of MA that supplying the intestines. Materials and Methods: Thirty-two chicken embryos aged 18 days were used in the study. Meconium is fractioned into water and lipid phases. MA tissues were divided into four groups. Only one MA tissue from each embryo prepared and suspended in the organ bath. Isometric contraction responses were created in MA tissues by one hour of incubation in Krebs-Henseleit solution for the control group and in water or lipid phase meconium prepared with 1/400 concentration of Krebs-Henseleit solution for other groups. In addition, isometric contraction responses were created in each MA tissue by KCl before and after incubation. Isometric contractions of MA were evaluated. Results: In water and lipid phase of meconium groups compared with the control group, isometric contractile responses at the end of the incubation were significantly different (p <0,05). When water phase of meconium group compared with lipid phase of meconium group, isometric contractile responses at the end of the incubation were significantly different (p <0,05). For meconium groups isometric contractile responses were compared before and after incubation and found significantly different (p <0,05). Conclusion: We determined that water phase of meconium causes more vasoconstructive effect on MA than lipid phase of meconium. Lipid phase of meconium increases the sensitivity to vasoconstructive agent. Meconium alone shows both effects and supports our findings. Key words: Gastroschisis, mesenteric artery, superior mesenteric artery, meconium.