HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 287/3/R642    most recent 00611.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Villamor, E. Articles by Blanco, C. E. Search for Related Content PubMed PubMed Citation Articles by Villamor, E. Articles by Blanco, C. E.

DEVELOPMENTAL PHYSIOLOGY AND PREGNANCY

Chronic in ovo hypoxia decreases pulmonary arterial contractile reactivity and induces biventricular cardiac enlargement in the chicken embryo

¹Department of Pediatrics, University Hospital Maastricht, Research Institute Growth and Development (GROW), University of Maastricht, 6202 AZ Maastricht;²Department of Pathology, University Hospital Maastricht, 6202 AZ Maastricht; and ⁴Department of Pharmacology and Toxicology, Cardiovascular Research Institute Maastricht, University of Maastricht, 6200 MD Maastricht, The Netherlands; and ³Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada M5S 1A8

Submitted 21 October 2003 ; accepted in final form 23 April 2004

Although chronic prenatal hypoxia is considered a major cause of persistent pulmonary hypertension of the newborn, experimental studies have failed to consistently find pulmonary hypertensive changes after chronic intrauterine hypoxia. We hypothesized that chronic prenatal hypoxia induces changes in the pulmonary vasculature of the chicken embryo. We analyzed pulmonary arterial reactivity and structure and heart morphology of chicken embryos maintained from days 6 to 19 of the 21-day incubation period under normoxic (21% O₂) or hypoxic (15% O₂) conditions. Hypoxia increased mortality (0.46 vs. 0.14; P < 0.01) and reduced the body mass of the surviving 19-day embryos (22.4 ± 0.5 vs. 26.6 ± 0.7 g; P < 0.01). A decrease in the response of the pulmonary artery to KCl was observed in the 19-day hypoxic embryos. The contractile responses to endothelin-1, the thromboxane A₂ mimetic U-46619, norepinephrine, and electrical-field stimulation were also reduced in a proportion similar to that observed for KCl-induced contractions. In contrast, no hypoxia-induced decrease of response to vasoconstrictors was observed in externally pipped 21-day embryos (incubated under normoxia for the last 2 days). Relaxations induced by ACh, sodium nitroprusside, or forskolin were unaffected by chronic hypoxia in the pulmonary artery, but femoral artery segments of 19-day hypoxic embryos were significantly less sensitive to ACh than arteries of control embryos [pD₂ (= –log EC₅₀): 6.51 ± 0.1 vs. 7.05 ± 0.1, P < 0.01]. Pulmonary vessel density, percent wall area, and periarterial sympathetic nerve density were not different between control and hypoxic embryos. In contrast, hypoxic hearts showed an increase in right and left ventricular wall area and thickness. We conclude that, in the chicken embryo, chronic moderate hypoxia during incubation transiently reduced pulmonary arterial contractile reactivity, impaired endothelium-dependent relaxation of femoral but not pulmonary arteries, and induced biventricular cardiac hypertrophy.

pulmonary hypertension; endothelium; cardiac hypertrophy

This article has been cited by other articles:

				P. Agren, A. L. Cogolludo, C. G. A. Kessels, F. Perez-Vizcaino, J. G. R. De Mey, C. E. Blanco, and E. Villamor Ontogeny of chicken ductus arteriosus response to oxygen and vasoconstrictors Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2007; 292(1): R485 - R496. [Abstract] [Full Text] [PDF]

				G. Sutendra and E. D. Michelakis The chicken embryo as a model for ductus arteriosus developmental biology: cracking into new territory Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2007; 292(1): R481 - R484. [Full Text] [PDF]