ABSTRACT
We determined whether store-operated channels (SOC) are involved in neonatal pulmonary artery function under conditions of acute and chronic hypoxia, using newborn sheep gestated and born either at high altitude (HA, 3,600 m) or low altitude (LA, 520 m). Cardiopulmonary variables were recorded in vivo, with and without SOC blockade by 2-aminoethyldiphenylborinate (2-APB), during basal or acute hypoxic conditions. 2-APB did not have effects on basal mean pulmonary arterial pressure (mPAP), cardiac output, systemic arterial blood pressure, or systemic vascular resistance in both groups of neonates. During acute hypoxia 2-APB reduced mPAP and pulmonary vascular resistance in LA and HA, but this reduction was greater in HA. In addition, isolated pulmonary arteries mounted in a wire myograph were assessed for vascular reactivity. HA arteries showed a greater relaxation and sensitivity to SOC blockers than LA arteries. The pulmonary expression of two SOC-forming subunits, TRPC4 and STIM1, was upregulated in HA. Taken together, our results show that SOC contribute to hypoxic pulmonary vasoconstriction in newborn sheep and that SOC are upregulated by chronic hypoxia. Therefore, SOC may contribute to the development of neonatal pulmonary hypertension. We propose SOC channels could be potential targets to treat neonatal pulmonary hypertension.
Subject(s)
Altitude , Ion Channels/physiology , Pulmonary Circulation/physiology , Sheep, Domestic/physiology , Altitude Sickness/blood , Altitude Sickness/complications , Altitude Sickness/genetics , Altitude Sickness/physiopathology , Animals , Animals, Newborn , Boron Compounds/pharmacology , Disease Models, Animal , Hemodynamics/drug effects , Hemodynamics/physiology , Humans , Hypoxia/blood , Hypoxia/complications , Hypoxia/genetics , Hypoxia/physiopathology , Infant, Newborn , Ion Channels/blood , Ion Channels/genetics , Persistent Fetal Circulation Syndrome/blood , Persistent Fetal Circulation Syndrome/etiology , Persistent Fetal Circulation Syndrome/physiopathology , Pulmonary Artery/physiopathology , Pulmonary Circulation/drug effects , Sheep, Domestic/blood , Sheep, Domestic/genetics , TRPC Cation Channels/blood , TRPC Cation Channels/physiology , Vasoconstriction/physiologyABSTRACT
We determined whether postnatal pulmonary hypertension induced by 70% of pregnancy at high altitude (HA) persists once the offspring return to sea level and investigated pulmonary vascular mechanisms operating under these circumstances. Pregnant ewes were divided into two groups: conception, pregnancy, and delivery at low altitude (580 m, LLL) and conception at low altitude, pregnancy at HA (3,600 m) from 30% of gestation until delivery, and return to lowland (LHL). Pulmonary arterial pressure (PAP) was measured in vivo. Vascular reactivity and morphometry were assessed in small pulmonary arteries (SPA). Protein expression of vascular mediators was determined. LHL lambs had higher basal PAP and a greater increment in PAP after N(G)-nitro-L-arginine methyl ester (20.9 ± 1.1 vs. 13.7 ± 0.5 mmHg; 39.9 ± 5.0 vs. 18.3 ± 1.3 mmHg, respectively). SPA from LHL had a greater maximal contraction to K(+) (1.34 ± 0.05 vs. 1.16 ± 0.05 N/m), higher sensitivity to endothelin-1 and nitroprusside, and persistence of dilatation following blockade of soluble guanylate cyclase. The heart ratio of the right ventricle-to-left ventricle plus septum was higher in the LHL relative to LLL. The muscle area of SPA (29.3 ± 2.9 vs. 21.1 ± 1.7%) and the protein expression of endothelial nitric oxide synthase (1.7 ± 0.1 vs. 1.1 ± 0.2), phosphodiesterase (1.4 ± 0.1 vs. 0.7 ± 0.1), and Ca(2+)-activated K(+) channel (0.76 ± 0.16 vs. 0.30 ± 0.01) were greater in LHL compared with LLL lambs. In contrast, LHL had decreased heme oxygenase-1 expression (0.82 ± 0.26 vs. 2.22 ± 0.44) and carbon monoxide production (all P < 0.05). Postnatal pulmonary hypertension induced by 70% of pregnancy at HA promotes cardiopulmonary remodeling that persists at sea level.
Subject(s)
Altitude Sickness/complications , Blood Pressure/physiology , Hypertension, Pulmonary/etiology , Hypoxia/complications , Lung/physiopathology , Prenatal Exposure Delayed Effects , Altitude , Altitude Sickness/physiopathology , Analysis of Variance , Animals , Blotting, Western , Female , Heart Rate/physiology , Hypertension, Pulmonary/physiopathology , Hypoxia/physiopathology , Muscle, Smooth, Vascular/physiopathology , Myography , Pregnancy , Pulmonary Artery/physiopathology , Reverse Transcriptase Polymerase Chain Reaction , Sheep , Vascular Resistance/physiologyABSTRACT
Se hace una revisión de la enfermedad de Niemann-Pick que es una alteración innata del metabolismo de los fosfolípidos, la ESPINGOMIELINA, que se acumula en los lisosomas, constituyendo la enfermedad lisosomal, debido a una alteración cualitativa o cuantitativa de la ESZPINGOMIELINASA. La enfermedad es transmitida en forma autosómica recesiva, alterando los diversos órganos, especialmente el sistema nervioso y el fondo de ojo en el cual se observa en la mácula una mancha de color cereza. A continuación se presenta el caso problema en un indígena puro del Cañar-Ecuador (años anteriores se encontró otro caso que fue descrito por su extrema rareza), existe consanguinidad; hepatoesplenomegalia, mancha roja en mácula y células espúmosas en médula ósea. Un hermano falleció con identicas características clínicas.
