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Distefano G, Sciacca P. Molecular physiopathogenetic mechanisms and development of new potential therapeutic strategies in persistent pulmonary hypertension of the newborn. Ital J Pediatr 2015; 41:6. [PMID: 25887340 PMCID: PMC4328557 DOI: 10.1186/s13052-015-0111-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 01/13/2015] [Indexed: 12/28/2022] Open
Abstract
Persistent pulmonary hypertension of the newborn (PPHN) is a cyanogenic plurifactorial disorder characterized by failed postnatal drop of pulmonary vascular resistance and maintenance of right-to-left shunt across ductus arteriosus and foramen ovale typical of intrauterine life. The pathogenesis of PPHN is very complex and can result from functional (vasoconstriction) or structural (arteriolar remodeling, reduced pulmonary vessels density) anomalies of pulmonary circulation. Etiopathogenetic factors heterogeneity can strongly condition therapeutical results and prognosis of PPHN that is particularly severe in organic forms that are usually refractory to selective pulmonary vasodilator therapy with inhaled nitric oxide. This paper reports the more recent acquisitions on molecular physiopathogenetic mechanisms underlying functional and structural forms of PPHN and illustrates the bases for adoption of new potential treatment strategies for organic PPHN. These strategies aim to reverse pulmonary vascular remodeling in PPHN with arteriolar smooth muscle hypertrophy and stimulate pulmonary vascular and alveolar growth in PPHN associated with lung hypoplasia.In order to restore lung growth in this severe form of PPHN, attention is focused on the results of studies of mesenchymal stem cells and their therapeutical paracrine effects on bronchopulmonry dysplasia, a chronic neonatal lung disease characterized by arrested vascular and alveolar growth and development of pulmonary hypertension.
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Affiliation(s)
- Giuseppe Distefano
- Department of Pediatrics, Pediatric Cardiology Service, University of Catania, Via S.Sofia 78, Catania, 95123, Italy.
| | - Pietro Sciacca
- Department of Pediatrics, Pediatric Cardiology Service, University of Catania, Via S.Sofia 78, Catania, 95123, Italy.
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Ichinose F, Roberts JD, Zapol WM. Inhaled nitric oxide: a selective pulmonary vasodilator: current uses and therapeutic potential. Circulation 2005; 109:3106-11. [PMID: 15226227 DOI: 10.1161/01.cir.0000134595.80170.62] [Citation(s) in RCA: 210] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Fumito Ichinose
- Department of Anesthesia and Critical Care, Massachusetts General Hospital, and Harvard Medical School, 55 Fruit St, Boston, Mass 02114, USA.
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Bell SG. The story of nitric oxide: from rascally radical to miracle molecule. Neonatal Netw 2004; 23:47-51. [PMID: 15317378 DOI: 10.1891/0730-0832.23.4.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
ONCE CONSIDERED AN environmental nuisance at best and a dangerous poison at worst, nitric oxide (NO) has been discovered to be an important biologic messenger, sending a shock wave through the scientific community. This article briefly reviews the discovery of NO as a regulator of vascular muscle tone and describes important events on its road to fame. The application of inhaled NO (iNO) for the treatment of hypoxic respiratory failure in neonates is discussed.
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Haas KM, Suzuki S, Yamaguchi N, Kato I, Ban K, Tanaka T, Fukuda S, Togari H. Nitric oxide further attenuates pulmonary hypertension in magnesium-treated piglets. Pediatr Int 2002; 44:670-4. [PMID: 12421268 DOI: 10.1046/j.1442-200x.2002.01632.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Persistent pulmonary hypertension of the newborn (PPHN) commonly appears as a complication of several pulmonary and non-pulmonary diseases. The hypoxia possibly inhibits Ca2+ +/- dependent K+ channels, thus resulting in membrane depolarization of pulmonary smooth muscle cells, which leads to the opening of Ca2+ channels and Ca2+ entry, resulting in contraction of the vascular smooth muscle. However, magnesium (Mg2+) is an antagonist of Ca2+. We studied the effect of magnesium sulfate on the treatment of hypoxia-induced pulmonary hypertension and compared to the site of action of nitric oxide (NO). METHODS Zero-day-old piglets were used in each experiment. The effects of Mg2+ were tested in each hypoxic, normoxic and hyperoxic states. Once the desired physical state was achieved, Mg2+ was administered at a dose of 100 mg/kg approximately every 10 min. In order to determine the exact mechanism of the Mg2+, Nw-nitro-l-arginine (LNNA), a NO synthase-inhibitor, was administered simultaneously with Mg2+ in some of the experiments. RESULTS There was a significant correlation between the percent reduction of the pulmonary arterial pressure (PAP) caused by magnesium and the level of oxygen (O2) present in the pulmonary artery. The greatest amount of reduction was seen in the hypoxic condition where the least amount of O2 is found. A further reduction in the PAP was seen when NO was given at the end of the Mg2+ trials. There was no significant reduction seen in the systemic arterial pressure. CONCLUSIONS Inhaled NO further reduced the PAP in piglets already treated with Mg2+.
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Affiliation(s)
- Kelly Mullins Haas
- Department of Pediatrics, Nagoya City University Medical School, Nagoya, Japan
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Abstract
UNLABELLED NO has been used successfully to treat PPHN, reducing the need for ECMO. NO has also been used in the cardiac catheterization laboratory to determine if pulmonary hypertension will decrease with NO. Patients who do not respond to NO are at higher risk after open-heart surgery, because their pulmonary hypertension will be difficult to treat. Postoperatively, NO can be used to determine if pulmonary hypertension is caused by vasoconstriction or by an obstruction. Inhaled Nitric Oxide at a Glance: ACTION Selective pulmonary vasodilation without systemic vasodilation. USE: Treatment of pulmonary hypertension. CONCENTRATION AND ROUTE Lowest concentration that will produce pulmonary vasodilation and improved oxygenation. Concentration should be kept < 80 ppm. CONTRAINDICATION Neonate that is ductal-dependent. TOXIC EFFECTS Keep methemoglobin level < 5%. Keep nitric dioxide, which can cause lung damage, < 7 ppm. Risk of bleeding. MONITOR Levels of NO/NO2. Platelets. Arterial blood gas (ABG). Methemoglobin. WEANING Decrease NO by 20%, monitoring ABG at 3- to 4-hour intervals. If there is a decrease in oxygenation, increase NO. Increase FIO2 20% when NO is discontinued. Unsuccessful treatment with NO--keep on NO until ECMO is available.
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Affiliation(s)
- Linda E Ware
- Le Bonheur Children's Medical Center, Memphis, Tennessee 38103, USA.
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Meyer C, Witte J, Hildmann A, Hennecke KH, Schunck KU, Maul K, Franke U, Fahnenstich H, Rabe H, Rossi R, Hartmann S, Gortner L. Neonatal screening for hearing disorders in infants at risk: incidence, risk factors, and follow-up. Pediatrics 1999; 104:900-4. [PMID: 10506232 DOI: 10.1542/peds.104.4.900] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To determine the incidence and risk factors for hearing disorders in a selected group of neonates and the feasibility of selective hearing screening. SETTINGS Multicenter prospective trial at five centers in Germany. METHODS Enrollment criteria: in addition to previously defined risk factors by the Joint Committee on Infant Hearing (family history of hearing loss, in utero infections, craniofacial anomalies, birth weight <1500 g, critical hyperbilirubinemia, ototoxic medications, bacterial meningitis, postnatal asphyxia, mechanical ventilation >5 days, stigmata, or syndromes associated with hearing loss), the impact of maternal drug abuse, birth weight <10th percentile, persistent pulmonary hypertension, and intracranial hemorrhage more than or equal to grade III or periventricular leukomalacia on infant hearing were evaluated. The screening procedure was performed by automated auditory brainstem response (A-ABR; ALGO 1-plus; Natus Med Inc, San Carlos, CA). STATISTICS univariate analyses of risk factors versus A-ABR results and a multivariate regression analysis were used; additionally, the total test time was recorded. RESULTS Seven hundred seventy recordings from 777 infants enrolled consecutively constitute the basis of this analysis. Mean gestational age was 33.8 +/- 4.3 weeks, birth weight 2141 +/- 968 g; 431 infants being male and 339 female; 41 (5.3%) infants exhibited pathologic A-ABR results (16 bilateral and 25 unilateral). Meningitis or sepsis, craniofacial malformations, and familial hearing loss were independent significant risk factors. Median total test time was 25 minutes. Follow-up examinations in 31 infants revealed persistent hearing loss in 18 infants (13 infants sensorineural, 5 from mixed disorders), 7 requiring amplification. CONCLUSION Hearing screening in high-risk neonates revealed a total of 5% of infants with pathologic A-ABR (bilateral 2%). Significant risk factors were familial hearing loss, bacterial infections, and craniofacial abnormalities. Other perinatal complications did not significantly influence screening results indicating improved perinatal handling in a neonatal population at risk for hearing disorders.
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Affiliation(s)
- C Meyer
- Children's Hospital, Medical University, Lübeck, Germany
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Kusuda S, Shishida N, Miyagi N, Hirabayashi M, Kim TJ. Cerebral blood flow during treatment for pulmonary hypertension. Arch Dis Child Fetal Neonatal Ed 1999; 80:F30-3. [PMID: 10325808 PMCID: PMC1720885 DOI: 10.1136/fn.80.1.f30] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To determine if the haemodynamics of systemic and cerebral circulation are changed during treatment for persistent pulmonary hypertension of the newborn (PPHN). METHODS Fifteen term newborn piglets with hypoxia induced pulmonary hypertension were randomly assigned either tolazoline infusion (Tz), hyperventilation alkalosis(HAT), and inhaled nitric oxide (iNO). Mean pulmonary arterial pressure (PAP), mean systemic arterial pressure (SAP), and cerebral blood flow volume (CBF) were measured. RESULTS During hypoxic breathing, PAP increased significantly in all groups. After treatment PAP decreased significantly in all groups, but no significant difference was observed between groups. SAP decreased significantly only in the Tz group, and CBF reduced significantly only in the HAT group. On the other hand, iNO did not change SAP or CBF. CONCLUSION Inhaled NO might be ideal for the resolution of pulmonary hypertension.
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Affiliation(s)
- S Kusuda
- Department of Neonatology, Osaka City General Hospital, Japan.
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Soukka H, Viinikka L, Kääpä P. Involvement of thromboxane A2 and prostacyclin in the early pulmonary hypertension after porcine meconium aspiration. Pediatr Res 1998; 44:838-42. [PMID: 9853915 DOI: 10.1203/00006450-199812000-00003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Severe perinatal aspiration of meconium is frequently complicated by unsuccessful neonatal adaptation with associated pulmonary hypertension. This vascular complication is supposedly related to pulmonary release of vasoconstrictory agents, including metabolites of arachidonic acid. Thus, to investigate the role of prostanoids on these meconium-induced circulatory changes in the lungs, the hemodynamic response to meconium instillation was studied in acetylsalicylic acid-pretreated juvenile pigs. Twelve 10-wk-old pigs with adapted lung circulation received 3 mL/kg of 65 mg/mL human meconium via the endotracheal tube. Six of them were medicated with 10 mg/kg acetylsalicylic acid 30 min before meconium insufflation. Hemodynamic parameters and urinary excretion of stable metabolites of thromboxane A2 and prostacyclin were measured serially for 6 h after the insult. Meconium administration induced a biphasic increase in mean pulmonary artery pressure and pulmonary vascular resistance, and a rapid rise in urinary levels of prostanoid metabolites. Acetylsalicylic acid pretreatment prevented the initial (0-1 h) pulmonary hypertensive response and increase in prostanoid excretion. During the second phase (1-6 h), acetylsalicylic acid did not attenuate the progressive increase in mean pulmonary artery pressure and pulmonary vascular resistance nor did it affect the longitudinal distribution of the pulmonary resistances. Our results thus show that in adapted porcine lungs, arachidonic acid metabolites contribute to the early hypertensive response, but have only minor effects during the second phase vascular hypertension.
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Affiliation(s)
- H Soukka
- Department of Pediatrics, University of Turku, Finland
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Wessel DL, Adatia I, Van Marter LJ, Thompson JE, Kane JW, Stark AR, Kourembanas S. Improved oxygenation in a randomized trial of inhaled nitric oxide for persistent pulmonary hypertension of the newborn. Pediatrics 1997; 100:E7. [PMID: 9347001 DOI: 10.1542/peds.100.5.e7] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE To determine the effect of inhaled nitric oxide (NO) on clinical outcome in newborns with persistent pulmonary hypertension (PPHN). DESIGN A prospective, randomized trial of patients referred to a level 3 nursery in a single large center. Clinicians were not masked to group assignment. Crossover of patients from control to NO treatment was not permitted. METHODS We randomized 49 mechanically ventilated newborns, transferred to our center with clinical and echocardiographic evidence of severe PPHN (arterial oxygen tension [PaO2] <100; fractional inspired oxygen = 1) to treatment with or without NO. Patients with gestational age <34 weeks or with congenital heart disease or diaphragmatic hernia were excluded. High-frequency oscillatory ventilation was used but not allowed concomitantly with NO. Primary outcome variables were oxygenation, mortality, and use of extracorporeal membrane oxygenation (ECMO). RESULTS Meconium aspiration syndrome and isolated PPHN were the most common diagnoses (32/49) and were distributed equally between groups. The median age at the time of entry into the study was similar between groups, 25 hours for control patients and 18 hours for NO patients. Median baseline oxygenation index (OI) was similar in 23 control (OI = 29) and 26 NO (OI = 30) patients. Mortality (8%), use of ECMO (33%), median days on mechanical ventilation (9 days), and duration of supplemental oxygen (13 days) were not different between treatment groups. PaO2, oxygen saturation, and OI improved in the NO group compared with baseline and to control patients at 15 minutes. The median percent change in OI (-31%) in the NO group was significantly different from baseline and from the control group. The difference in oxygenation between treatment groups was still apparent 12 hours after baseline. Before cannulation for ECMO, oxygenation was better in the NO group compared with control patients. Among patients who were placed on ECMO, the median time from baseline to ECMO cannulation was 2.4 hours (range, 1 to 12 hours) among control patients and 3.3 hours (range, 2 to 68 hours) for those randomized to receive NO. There was a tendency to observe fewer adverse neurologic events (seizure and intracranial hemorrhage) in the NO group (4/26 vs 8/23). One child with alveolar capillary dysplasia confirmed by postmortem examination could not be weaned from 80 parts per million of NO and transiently developed methemoglobinemia (peak methemoglobin level = 17%). No other side effects were observed. CONCLUSIONS Although mortality and ECMO use were similar for both treatment groups using this study size and design, sustained improvement in oxygenation with NO and better oxygenation at initiation of ECMO may have important clinical benefits. We speculate that modification of treatment to include specific lung expansion strategies with NO treatment and recognition that early improvement of oxygenation may be sustained with NO may lead to reduced use of ECMO in NO treated patients compared with controls.
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Affiliation(s)
- D L Wessel
- Department of Cardiology, Harvard Medical School, Boston, Massachusetts, USA
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Frenckner B, Ehrén H, Granholm T, Lindén V, Palmér K. Improved results in patients who have congenital diaphragmatic hernia using preoperative stabilization, extracorporeal membrane oxygenation, and delayed surgery. J Pediatr Surg 1997; 32:1185-9. [PMID: 9269967 DOI: 10.1016/s0022-3468(97)90679-5] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Congenital diaphragmatic hernia (CDH) is associated with pulmonary hypoplasia. The pulmonary vascular bed may be extremely reactive to various stimuli, and in the treatment it is important to avoid pulmonary vasospasm. The strategy in our institution since 1990 has involved a prolonged preoperative stabilization with gentle mechanical ventilation. Pressures have been kept as low as possible, and slight hypercarbia has been accepted. Peak inspiratory pressures exceeding 35 cm H2O have been avoided. Extracorporeal membrane oxygenation (ECMO) has been used according to standard inclusion criteria. Nitric oxide and high-frequency oscillation have been added to the therapeutic modalities during the study period. When the patient was considered stabilized, surgical repair was undertaken after a delay of 24 to 96 hours. In patients on ECMO who could not be decannulated, surgical repair was undertaken while on ECMO. From 1990 through 1995, 52 patients were admitted with a diagnosis of CDH. Forty-three of these were risk group patients presenting with respiratory distress within 6 hours after birth. A total of 48 patients survived (survival rate 92%), and 39 of the risk group patients (survival rate 91%). There were only four hospital deaths, all with contraindications to ECMO. It is suggested that the adopted protocol is beneficial in the treatment of CDH and that the fraction of patients who have pulmonary hypoplasia incompatible with life is smaller than previously believed.
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Affiliation(s)
- B Frenckner
- Department of Pediatric Surgery, St Goran's/Karolinska Hospital, Stockholm, Sweden
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Irish MS, Kapur P, Glick PL. Additional considerations for inhaled nitric oxide therapy in congenital diaphragmatic hernia. Pediatr Surg Int 1997; 12:466-7. [PMID: 9244132 DOI: 10.1007/bf01076972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Sheridan RL, Hurford WE, Kacmarek RM, Ritz RH, Yin LM, Ryan CM, Tompkins RG. Inhaled nitric oxide in burn patients with respiratory failure. THE JOURNAL OF TRAUMA 1997; 42:629-34. [PMID: 9137249 DOI: 10.1097/00005373-199704000-00008] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Inhaled nitric oxide (NO) has the potential to improve ventilation/perfusion matching and decrease pulmonary artery pressure in patients with profound respiratory failure. METHODS Eight patients, average age of 35 years (range, 2.5-77 years) and burn size 49% (range, 19-80%), with inhalation injury and respiratory failure failing conventional management (average Pao2/FiO2 ratio (PFR) 85) were given inhaled NO at 20 ppm. RESULTS An immediate mean increase in PFR of 10% and a decrease in pulmonary artery mean pressure of 7.8% was noted. At 24 hours, the average improvement in PFR was 28% and that in pulmonary artery mean pressure was 7.7%. Although not reaching statistical significance, these changes were more pronounced in those patients who went on to survive. There was no hypotension attributed to NO administration, and maximum methemoglobin levels averaged 0.9%. CONCLUSIONS Inhaled NO can be safely administered to selected burn patients with severe respiratory failure who are perceived to be failing conventional support. Although current data are not adequate to support its general use, an immediate and sustained improvement in PFR and pulmonary artery mean pressure may correlate with eventual recovery of pulmonary function. Continued evaluation in controlled settings seems warranted and is in progress.
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Affiliation(s)
- R L Sheridan
- Surgical Service, Massachusetts General Hospital, Boston, USA
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MESH Headings
- Cystic Adenomatoid Malformation of Lung, Congenital/diagnostic imaging
- Ductus Arteriosus, Patent/diagnostic imaging
- Hernia, Diaphragmatic/diagnostic imaging
- Humans
- Infant, Newborn
- Infant, Newborn, Diseases/diagnostic imaging
- Infant, Premature, Diseases/diagnostic imaging
- Lung/abnormalities
- Lung/diagnostic imaging
- Radiography, Thoracic
- Respiratory Distress Syndrome, Newborn/diagnostic imaging
- Ultrasonography
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Affiliation(s)
- A T Gibson
- Neonatal Intensive Care Unit, Jessop Hospital for Women, Sheffield, UK
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Burton PR, Gurrin LC, Hussey MH. Interpreting the clinical trials of extracorporeal membrane oxygenation in the treatment of persistent pulmonary hypertension of the newborn. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s1084-2756(97)80026-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2022]
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Pérez-Vizcaíno F, Villamor E, Moro M, Tamargo J. Pulmonary versus systemic effects of vasodilator drugs: an in vitro study in isolated intrapulmonary and mesenteric arteries of neonatal piglets. Eur J Pharmacol 1996; 314:91-8. [PMID: 8957223 DOI: 10.1016/s0014-2999(96)00548-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The ability of several vasodilators to inhibit the responses to noradrenaline and U46619 (a thromboxane A2 analog) in isolated pulmonary and mesenteric arteries of neonatal piglets was compared. In pulmonary arteries, acetylcholine produced endothelium-dependent relaxations (pIC50 = about 6.8) while, in mesenteric arteries, a relaxant (< or = 10(-7) M) or a contractile response (> or = 10(-6) M) was observed. Sodium nitroprusside produced relaxant effects in pulmonary and mesenteric arteries contracted by noradrenaline (pIC50 = 6.6 and 6.0, respectively) and U46619 (pIC50 = 5.4 and 6.7, respectively). ATP induced an endothelium-independent relaxation in pulmonary arteries (pIC50 = about 4) but in mesenteric arteries it produced weak relaxant effects. In resting mesenteric arteries, ATP induced a concentration-dependent contraction which was not observed in pulmonary arteries. Prostaglandin E1 induced a contractile effect whereas, at higher concentrations, a relaxant response was observed. The alpha-adrenoceptor antagonist tolazoline had no effect on arteries contracted by U46619 but relaxed arteries contracted by noradrenaline being slightly more potent in mesenteric than in pulmonary arteries (pIC50 = 5.1 and 4.8, respectively). Nifedipine (> 10(-7) M) relaxed both arteries, mesenteric being more sensitive than pulmonary arteries and noradrenaline more sensitive than U46619-induced contractions. In conclusion, differences in the relaxant effects for all vasodilators were found depending on the artery, the vasoconstrictor used or both. However, ATP was the only drug which, regardless of the concentration or vasoconstrictor used, produced greater relaxant effects in pulmonary than in mesenteric arteries.
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Affiliation(s)
- F Pérez-Vizcaíno
- Department of Pharmacology, School of Medicine, Universidad Complutense, Madrid, Spain
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Villamor E, Pérez-Vizcaíno F, Ruiz T, Tamargo J, Moro M. In vitro effects of magnesium sulfate in isolated intrapulmonary and mesenteric arteries of piglets. Pediatr Res 1996; 39:1107-12. [PMID: 8725278 DOI: 10.1203/00006450-199606000-00029] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Magnesium sulfate (MgSO4) has been proposed to be an efficient treatment in persistent pulmonary hypertension of the newborn. We compared the ability of MgSO4 to inhibit the responses to several vasoconstrictors in isolated intrapulmonary and mesenteric arteries from 10-17-d-old piglets. MgSO4 (3-100 mM) produced a slight vasodilator effect in pulmonary arteries precontracted with the thromboxane A2 mimetic U46619 (10(-6) M), noradrenaline (10(-5) M), and KCl (80 mM) (15.1 +/- 3.7%; 20 +/- 3.33%; 10.4 +/- 0.9% at 100 mM MgSO4 respectively). In contrast, in mesenteric arteries MgSO4, produced a marked vasodilation (80.4 +/- 4.0%, 93.1 +/- 3.46%, and 87.5 +/- 1.93% at 100 mM MgSO4, respectively, p < 0.01 versus pulmonary arteries). The vasodilator effect of MgSO4 was endothelium-independent and reversed by increasing the extracellular Ca2+ concentration. After incubation for 1 h of pulmonary arteries with three different MgSO4 concentrations (0, 1.2, and 4.8 mM) there were no differences in the contractile responses to U46619 nor in the vasodilator effects of acetylcholine or sodium nitroprusside. Rapid removal of Mg2+ from bath medium produced a transient vasodilation which was more marked in pulmonary than in mesenteric arteries and was greatly reduced by the removal of endothelium or by the nitric oxide synthase inhibitor L-NAME (10(-4) M). We conclude that MgSO4 is a poor vasodilator of pulmonary arteries in vitro and at physiologic concentrations appears to inhibit nitric oxide release from the pulmonary endothelium. Thus, the possible beneficial clinical effects of MgSO4 in persistent pulmonary hypertension of the newborn do not seem to be related to a direct effect on pulmonary vascular smooth muscle.
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Affiliation(s)
- E Villamor
- Department of Pediatrics, Hospital Universitario San Carlos, Madrid, Spain
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Affiliation(s)
- C A Heal
- Neonatal Unit, North Staffordshire Hospital, Stoke-on-Trent, UK
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Fineman JR, Zwass MS. Inhaled nitric oxide therapy for persistent pulmonary hypertension of the newborn. ACTA PAEDIATRICA JAPONICA : OVERSEAS EDITION 1995; 37:425-30. [PMID: 7572140 DOI: 10.1111/j.1442-200x.1995.tb03350.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Increasing evidence suggests that the pulmonary vascular endothelium is an important mediator of resting pulmonary vascular tone through the synthesis and release of a variety of vasoactive substances including nitric oxide (NO). In addition, pulmonary endothelial dysfunction (such as impairment of NO synthesis) is present in lung injury and may contribute to the pathophysiology of pulmonary hypertensive disorders. Recently, exogenously administered NO gas has been utilized to treat infants with persistent pulmonary hypertension of the newborn (PPHN). These preliminary studies suggest that inhaled NO is a promising new therapy for the treatment of infants with PPHN. Controlled clinical trials must now be performed to determine if the use of inhaled NO improves the long-term outcome of patients with PPHN. Long-term exposure must be monitored closely for potential toxicity which includes methemoglobinemia and lung injury secondary to peroxynitrite and nitrogen dioxide production.
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Affiliation(s)
- J R Fineman
- Department of Pediatrics, University of California, San Francisco, USA
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Henneberg SW, Jepsen S, Andersen PK, Pedersen SA. Inhalation of nitric oxide as a treatment of pulmonary hypertension in congenital diaphragmatic hernia. J Pediatr Surg 1995; 30:853-5. [PMID: 7666321 DOI: 10.1016/0022-3468(95)90763-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Congenital diaphragmatic hernia (CDH) still has a mortality risk of around 40%. The concomitant pulmonary hypoplasia and the persistent pulmonary hypertension are of major prognostic importance. The use of a selective pulmonary vasodilator may revert this vicious circle that is fatal to many children. Inhalation of nitric oxide (NO) has been suggested as a rational treatment of this condition. The authors report three cases of high-risk infants with CDH where NO was used successfully. It is concluded that hypoxemia in CDH can be treated successfully with NO inhalation when conventional treatment fails, and it may in some cases prove to be an alternative to ECMO.
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Affiliation(s)
- S W Henneberg
- Department of Anaesthesia and Intensive Care, Odense University Hospital, Denmark
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Schachtner SK, Rome JJ, Hoyt RF, Newman KD, Virmani R, Dichek DA. In vivo adenovirus-mediated gene transfer via the pulmonary artery of rats. Circ Res 1995; 76:701-9. [PMID: 7728986 DOI: 10.1161/01.res.76.5.701] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Gene transfer into the pulmonary vasculature has the potential to be a powerful technique for both investigation of pulmonary pathophysiology and development of genetic therapies for pulmonary vascular disease. To evaluate the potential for in vivo pulmonary arterial gene transfer, we infused adenoviral vectors into the left pulmonary artery of Sprague-Dawley and cotton rats. Access to the left pulmonary artery was obtained by a percutaneous transcatheter approach or through thoracotomy and pulmonary arteriotomy. With the thoracotomy approach, both pulmonary arterial inflow and pulmonary venous outflow were occluded during vector influsion and throughout a subsequent 20-minute dwell period. The success of gene transfer was assessed by staining for evidence of recombinant gene expression in lungs excised at time points ranging from 48 to 72 hours after virus infusion. With the thoracotomy technique, pulmonary gene transfer was successful in 15% of surviving Sprague-Dawley rats and 30% of surviving cotton rats. Percutaneous catheter-based pulmonary gene transfer was not successful. In rats with pulmonary gene transfer, 1% to 8% of total left lung cells expressed the recombinant gene. Recombinant gene expression was found in endothelial cells (0.2% to 18% of total transduced cells), smooth muscle cells (0% to 3%), macrophages (1% to 7%), airway epithelial cells (2% to 50%), and alveolar epithelial cells (38% to 94%). Investigation of the low rate of successful gene transfer in individual animals suggested that insufficient physical contact between the virions and pulmonary cells was the most likely cause. In vivo gene transfer into the rat pulmonary vasculature can be accomplished with adenovirus vectors.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S K Schachtner
- Molecular Hematology Branch, National Heart, Lung, and Blood Institute, Bethesda, Md, USA
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Tolsa JF, Cotting J, Sekarski N, Payot M, Micheli JL, Calame A. Magnesium sulphate as an alternative and safe treatment for severe persistent pulmonary hypertension of the newborn. Arch Dis Child Fetal Neonatal Ed 1995; 72:F184-7. [PMID: 7796235 PMCID: PMC2528455 DOI: 10.1136/fn.72.3.f184] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Eleven newborns admitted consecutively to the neonatal unit with respiratory failure and severe persistent pulmonary hypertension (PPHN) were included in a clinical trial to assess the efficacy of magnesium sulphate (MgSO4) in the treatment of PPHN. A loading dose of 200 mg/kg MgSO4 was given over 20 minutes, followed by a continuous infusion of 20-150 mg/kg/hour to obtain a magnesium blood concentration between 3.5 and 5.5 mmol/l. Mean (SD) duration of treatment was 75.5 (19.8) hours. No other vasodilatory drug was administered before or during the treatment and patients were not hyperventilated. Mean (SEM) PaO2 values significantly increased from 42.6 (8.8) before treatment to 70.3 (24.1) mm Hg after 24 hours, with no change in pH or PCO2. Oxygen index and alveolar-arterial oxygen gradient (A-aDO2) were significantly lower after 24 hours; respectively, 46.8 (15.2) to 28.0 (9.0) and 624.3 (11.3) to 590 (58) mm Hg. Mean airway pressure could be significantly reduced from 19.5 (3.1) to 13.9 (3.9) cm H2O after 72 hours. Mean ventilatory time support was 131 hours and mean total oxygen dependency 10 days. No systemic hypotension nor any other adverse effect were noted. All infants survived and the neurodevelopmental assessment was normal at 6 and 12 months of age. It is concluded that magnesium sulphate is a non-aggressive and low-cost treatment of short duration which is easy to apply. It may have a role in the various treatment of PPHN.
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Affiliation(s)
- J F Tolsa
- Paediatric Department, University Hospital, Lausanne, Switzerland
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