Monitoring breathing in avian embryos and hatchlings by the barometric technique

Szdzuy, Kirsten; Mortola, Jacopo P.

doi:10.1016/j.resp.2007.07.004

Cited by 26 publications

(20 citation statements)

References 9 publications

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“…Figure 6 shows examples of different respiration signals derived from the navigator echoes, it is clear that different eggs are at different stages in this respiratory transition. These results are also consistent with other studies which have reported respiration rates of 72.7 breaths per minute at 19.9 days of incubation (26) and 51 breaths per minute at 20 days of incubation (24). A subsequent T2 scan of egg 1, shown in Fig.…”

Section: Cine Mri Of Late Stage Embryossupporting

confidence: 92%

In ovo non‐invasive quantification of the myocardial function and mass of chick embryos using magnetic resonance imaging

et al. 2009

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Magnetic resonance imaging (MRI) has evolved as one of the major non-invasive tools to study healthy and diseased hearts in animal models, especially rodent models. Even though, the chick embryo has long been used as a model for cardiovascular research, MRI has not yet been used for in vivo cardiac studies. Part of the reason for this is the difficulty in monitoring the ECG and respiration of the chick embryo in the magnet for gating purposes. To overcome this complication, this paper presents the use of retrospective Cine MRI to measure the cardiac function of chick embryos in ovo for the first time, without the need for respiratory or cardiac gating. The resulting left ventricular functional parameters, from six chick embryos at 20 days of incubation, were (mean W SD) EDV 69 W 15 mL, ESV 31 W 7 mL, SV 38 W 9 mL and EF 54.5 W 2%. The use of retrospective Cine MRI at earlier stages of development is also discussed and difficulties have been highlighted.

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Section: Cine Mri Of Late Stage Embryossupporting

confidence: 92%

In ovo non‐invasive quantification of the myocardial function and mass of chick embryos using magnetic resonance imaging

et al. 2009

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“…The barometric technique has the advantage of noninvasiveness, but it is prone to errors in the computation of VT when the T difference between body and ambient is small (26). The present setup, therefore, was designed to retain a rather large T difference (almost 10°C) while keeping the hatchling at its customary ambient T of ϳ38°C (40). Because these conditions remained the same for both experimental groups and responses were analyzed as percent of the air values, it is extremely unlikely that the observed differences in chemosensitivity between Nx and Hx reflected a systematic error introduced by the methodology.…”

Section: Discussionmentioning

confidence: 99%

“…26), including the chick embryo (21,22). Details of the methodology, possible problems, and validation have been discussed elsewhere (40). Briefly, the animal chamber was separated into two sections, a smaller animal compartment, acting as a "nest," of ϳ100 ml, where the hatchling was positioned, and a larger outer compartment of ϳ200 ml.…”

mentioning

confidence: 99%

Ventilatory chemosensitivity of the 1-day-old chicken hatchling after embryonic hypoxia

Szdzuy

Mortola²

2007

American Journal of Physiology-Regulatory, Integrative and Comp

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Szdzuy K, Mortola JP. Ventilatory chemosensitivity of the 1-dayold chicken hatchling after embryonic hypoxia. Am J Physiol Regul Integr Comp Physiol 293: R1640-R1649, 2007. First published August 8, 2007; doi:10.1152/ajpregu.00422.2007.-We investigated the effects of sustained embryonic hypoxia on the neonatal ventilatory chemosensitivity. White Leghorn chicken eggs were incubated at 38°C either in 21% O 2 throughout incubation (normoxia, Nx) or in 15% O 2 from embryonic day 5 (hypoxia, Hx), hatching time included. Hx embryos hatched ϳ11 h later than Nx, with similar body weights. Measurements of gaseous metabolism (oxygen consumption, V O2) and pulmonary ventilation (V E) were conducted either within the first 8 h (early) or later hours (late) of the first posthatching day. In resting conditions, Hx had similar V O2 and body temperature (Tb) and slightly higher V E and ventilatory equivalent (V E/V O2) than Nx. Ventilatory chemosensitivity was evaluated from the degree of hyperpnea (increase in V E) and of hyperventilation (increase in V E/V O2) during acute hypoxia (15 and 10% O2, 20 min each) and acute hypercapnia (2 and 4% CO2, 20 min each). The chemosensitivity differed between the early and late hours, and at either time the responses to hypoxia and hypercapnia were less in Hx than in Nx because of a lower increase in V E and a lower hypoxic hypometabolism. In a second group of Nx and Hx hatchlings, the V E response to 10% O2 was tested in the same hatchlings at the early and late hours. The results confirmed the lower hypoxic chemosensitivity of Hx. We conclude that hypoxic incubation affected the development of respiratory control, resulting in a blunted ventilatory chemosensitivity. developmental plasticity; epigenetic adaptation; hypercapnia; hypometabolism; hypoxic ventilatory response IN MAMMALS AND BIRDS, the development of the respiratory system is a long process. It begins early during gestation or incubation, when the embryo's gas-exchange needs are provided by nonpulmonary organs, and continues far into postnatal life, when pulmonary ventilation is the only means of fulfilling the aerobic requirements of the growing organism. A question of both biological and clinical interest is whether or not this process is strictly under genetic control or can be modulated by external events. In this latter case, the rather long time for structural and functional development gives the respiratory system the opportunity of adjusting to the postnatal changes in metabolic needs. Equally, however, it opens a potentially risky time window for environmental factors to interfere negatively with the normal development of the mechanisms of respiratory control, including ventilatory chemosensitivity.Several studies have questioned whether the ventilatory responses to hypoxia or hypercapnia reflect a genetically controlled and fixed program or are a phenotypic trait that can be modified through experiences, a phenomenon often referred to as developmental plasticity (18; see Ref. 7 for review). For example, studies on ...

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“…Safety studies of respiratory function in adult and juvenile animals are usually monitored in head-out or whole-body plethysmographs. Whereas measuring respiratory function in a mammalian fetus requires invasive or indirect electrophysiology or imaging techniques (Greer, 2012), the same monitoring in the chicken fetus can be performed using noninvasive barometric methods, a real advantage of the chicken embryo model system (Szdzuy and Mortola, 2007).…”

Section: Expanding the Use Of The Chicken Embryo Modelmentioning

confidence: 99%

Cracking the Egg: Potential of the Developing Chicken as a Model System for Nonclinical Safety Studies of Pharmaceuticals

Bjørnstad

Austdal

Roald

et al. 2015

J Pharmacol Exp Ther

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The advance of perinatal medicine has improved the survival of extremely premature babies, thereby creating a new and heterogeneous patient group with limited information on appropriate treatment regimens. The developing fetus and neonate have traditionally been ignored populations with regard to safety studies of drugs, making medication during pregnancy and in newborns a significant safety concern. Recent initiatives of the Food and Drug Administration and European Medicines Agency have been passed with the objective of expanding the safe pharmacological treatment options in these patients. There is a consensus that neonates should be included in clinical trials. Prior to these trials, drug leads are tested in toxicity and pharmacology studies, as governed by several guidelines summarized in the multidisciplinary International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use M3 (R2). Pharmacology studies must be performed in the major organ systems: cardiovascular, respiratory, and central nervous system. The chicken embryo and fetus have features that make the chicken a convenient animal model for nonclinical safety studies in which effects on all of these organ systems can be tested. The developing chicken is inexpensive, accessible, and nutritionally self-sufficient with a short incubation time and is ideal for drug-screening purposes. Other high-throughput models have been implemented. However, many of these have limitations, including difficulty in mimicking natural tissue architecture and function (human stem cells) and obvious differences from mammals regarding the respiratory organ system and certain aspects of central nervous system development (Caenorhabditis elegans, zebrafish).This minireview outlines the potential and limitations of the developing chicken as an additional model for the early exploratory phase of development of new pharmaceuticals.

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Monitoring breathing in avian embryos and hatchlings by the barometric technique

Cited by 26 publications

References 9 publications

In ovo non‐invasive quantification of the myocardial function and mass of chick embryos using magnetic resonance imaging

In ovo non‐invasive quantification of the myocardial function and mass of chick embryos using magnetic resonance imaging

Ventilatory chemosensitivity of the 1-day-old chicken hatchling after embryonic hypoxia

Cracking the Egg: Potential of the Developing Chicken as a Model System for Nonclinical Safety Studies of Pharmaceuticals

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