These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Major vasodilator role for nitric oxide in the gastrointestinal circulation of the mid-gestation fetal lamb.
    Author: Fan WQ, Smolich JJ, Wild J, Yu VY, Walker AM.
    Journal: Pediatr Res; 1998 Sep; 44(3):344-50. PubMed ID: 9727711.
    Abstract:
    As nitric oxide (NO) may be a particularly important vasodilator in early life, we investigated its role in the regulation of the gastrointestinal (GI) circulation at mid-gestation. Cardiac output and GI blood flow were measured by the radioactive microsphere technique in eight chronically instrumented and unanesthetized mid-gestation fetal sheep. Mean arterial pressure (MAP), heart rate, blood flow, oxygen delivery, and vascular resistance were determined before and after infusion of the specific NO synthase inhibitor, Nomega-nitro-L-arginine (L-NNA) at doses of 10 and 25 mg/kg. In response to L-NNA infusion, MAP increased (p < 0.01) and combined ventricular output decreased (p < 0.001). GI blood flow and oxygen delivery decreased and vascular resistance increased in the stomach and all segments of the small and large intestine (all p < 0.001). The greatest reduction in blood flow was in the small intestine (p < 0.01) and the basal differential pattern of small intestinal blood flow exceeding large intestinal flow was completely abolished. These changes were much greater than those previously described in late-gestation fetuses. Our results suggest that, at mid-gestation, NO plays a major role in the regulation of blood flow and vascular tone across all segments of the fetal GI tract, with its effects being more pronounced than later in development.
    [Abstract] [Full Text] [Related] [New Search]