Fetal and postnatal ovine mesenteric vascular reactivity

Jayasree Nair, Sylvia F. Gugino, Lori C. Nielsen, Michael G. Caty, Satyanarayana Lakshminrusimha

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Background:Intestinal circulation and mesenteric arterial (MA) reactivity may play a role in preparing the fetus for enteral nutrition. We hypothesized that MA vasoreactivity changes with gestation and vasodilator pathways predominate in the postnatal period.Methods:Small distal MA rings (0.5-mm diameter) were isolated from fetal (116-d, 128-d, 134-d, and 141-d gestation, term ∼ 147 d) and postnatal lambs. Vasoreactivity was evaluated using vasoconstrictors (norepinephrine (NE) after pretreatment with propranolol and endothelin-1(ET-1)) and vasodilators (NO donors A23187 and s-nitrosopenicillamine (SNAP)). Protein and mRNA assays for receptors and enzymes (endothelin receptor A, alpha-adrenergic receptor 1A (ADRA1A), endothelial NO synthase (eNOS), soluble guanylyl cyclase (sGC), and phosphodiesterase5 (PDE5)) were performed in mesenteric arteries.Results:MA constriction to NE and ET-1 peaked at 134 d. Relaxation to A23187 and SNAP was maximal after birth. Basal eNOS activity was low at 134 d. ADRA1A mRNA and protein increased significantly at 134 d and decreased postnatally. sGC and PDE5 protein increased from 134 to 141 d.Conclusion:Mesenteric vasoconstriction predominates in late-preterm gestation (134 d; the postconceptional age with the highest incidence of necrotizing enterocolitis (NEC)) followed by a conversion to vasodilatory influences near the time of full-term birth. Perturbations in this ontogenic mechanism, including preterm birth, may be a risk factor for NEC.

Original languageEnglish (US)
Pages (from-to)575-582
Number of pages8
JournalPediatric Research
Volume79
Issue number4
DOIs
StatePublished - Apr 1 2016
Externally publishedYes

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

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