Chicken embryos can maintain heart rate during hypoxia on day 4 of incubation
- 20 March 2020
- journal article
- research article
- Published by Springer Science and Business Media LLC in Journal of Comparative Physiology B
- Vol. 190 (3), 361-370
- https://doi.org/10.1007/s00360-020-01274-5
Abstract
Acute exposure to hypoxic conditions is a frequent natural event during the development of bird eggs. However, little is known about the effect of such exposure on the ability of young embryos in which cardiovascular regulation is not yet developed to maintain a normal heart rate (HR). To address this question, we studied the effect of 10–20 min of exposure to moderate or severe acute hypoxia (10% or 5% O2, respectively) on the HR of day 4 (D4) chicken embryos. In ovo, video recording of the beating embryo heart inside the egg revealed that severe, but not moderate, hypoxia resulted in significant HR changes. The HR response to severe hypoxia consisted of two phases: the first phase, consisting of an initial decrease in HR, was followed by a phase of partial HR recovery. Upon the restoration of normoxia, after an overshoot period of a few minutes, the HR completely recovered to its basal level. In vitro (isolated heart preparation), the first phase of the HR response to severe hypoxia was strengthened (nearly complete heart silencing) compared to that in ovo, and the HR recovery phase was greatly attenuated. Furthermore, neither an overshoot period nor complete HR recovery after hypoxia was observed. Thus, the D4 chicken embryo heart can partially maintain its rhythm during hypoxia in ovo, but not in vitro. Some factors from the egg, such as catecholamines, are likely to be critical for avian embryo responding to hypoxic condition and survival.Keywords
Funding Information
- IDB RAS and IEPB RAS Government basic research programs (№ 0108-2019-0003, № 075-00776-19-02)
This publication has 74 references indexed in Scilit:
- Biomechanics of early cardiac developmentBiomechanics and Modeling in Mechanobiology, 2012
- Optical coherence tomography captures rapid hemodynamic responses to acute hypoxia in the cardiovascular system of early embryosDevelopmental Dynamics, 2012
- Yolk sac endoderm is the major source of serum proteins and lipids and is involved in the regulation of vascular integrity in early chick developmentDevelopmental Dynamics, 2011
- Do monoamine-synthesizing cells constitute a complex network of oxygen sensors?Medical Hypotheses, 2010
- Hypoxia Induces Dilated Cardiomyopathy in the Chick Embryo: Mechanism, Intervention, and Long-Term ConsequencesPLOS ONE, 2009
- Chronic in ovo hypoxia decreases pulmonary arterial contractile reactivity and induces biventricular cardiac enlargement in the chicken embryoAmerican Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 2004
- Stress Responses in Avian EmbryosAmerican Zoologist, 1997
- Presence of serotonin in early chick embryosCell Differentiation, 1988
- Adaptations to Underground Nesting in Birds and ReptilesAmerican Zoologist, 1980
- A fluorescence study on the ability of the notochord to synthesize and store catecholamines in early chick embryosThe Anatomical Record, 1972