HS Increases Blood Pressure via Activation of L-Type Calcium Channels with Mediation by HS Generated from Reactions with Oxyhemoglobin.

Although the gasotransmitter hydrogen sulfide (HS) is well known for its vasodilatory effects, HS also exhibits vasoconstricting properties. Herein, it is demonstrated that administration of HS as intravenous sodium sulfide (NaS) increased blood pressure in sheep and rats, and this effect persisted after HS has disappeared from the blood. Inhibition of the L-type calcium channel (LTCC) diminished the hypertensive effects.

Quantitative susceptibility mapping as a measure of cerebral oxygenation in neonatal piglets.

Prominence of cerebral veins using susceptibility weighted magnetic resonance imaging (SWI) has been used as a qualitative indicator of cerebral venous oxygenation (CvO). Quantitative susceptibility mapping (QSM) adds more precision to the assessment of CvO, but has not been applied to neonatal hypoxic ischemic injury (HII). QSM measures of venous susceptibility and their correlation with direct measures of brain oxygenation and cerebral blood flow (CBF) in the neonatal piglet.

Evidence for placental-derived iron-nitrosyls in the circulation of the fetal lamb and against a role for nitrite in mediating the cardiovascular transition at birth.

Circulating metabolites of nitric oxide, such as nitrite, iron nitrosyls (FeNO), and nitrosothiols, have vasodilatory bioactivity. In both human and sheep neonates, plasma concentrations of these NO metabolite (NOx) concentrations fall >50% within minutes after birth, raising the possibility that circulating NOx plays a role in maintaining low fetal vascular resistance and in the cardiovascular transition at birth. To test whether the fall in plasma NOx concentrations at birth is due to either ligation of the umbilical cord or oxygenation of the fetus to newborn levels, plasma NOx concentrations were measured during stepwise delivery of near-term fetal lambs.

Inhaled Fasudil Lacks Pulmonary Selectivity in Thromboxane-Induced Acute Pulmonary Hypertension in Newborn Lambs.

Introduction: Pulmonary hypertension (PH) is a potentially deadly disease for infants and adults with few existing medical interventions and no cure. In PH, increased blood pressure in the pulmonary artery eventually leads to heart failure. Fasudil, an antagonist of Rho-kinase, causes vasodilation leading to decreased systemic artery pressure and pulmonary artery pressure (PAP).

Use of Esophageal Hemoximetry to Assess the Effect of Packed Red Blood Cell Transfusion on Gastrointestinal Oxygenation in Newborn Infants.

 There are no widely accepted methods of continuously monitoring gut oxygenation in the newborn during packed red blood cell transfusion. We investigated the use of an orally inserted light spectroscopy probe to measure lower esophageal oxyhemoglobin saturations (eStO) before, during, and after transfusion and made comparisons with abdominal near-infrared spectroscopy (NIRS) and superior mesenteric artery (SMA) flow.  Thirteen neonates with corrected gestational ages ranging from 22 weeks, 0 day to 37 weeks, 5 days were enrolled.