Chronic Hypoxia Induces Cardiomegaly and Increased Blood Flow Velocity during Chicken Heart Development

This research examines the effects of hypoxia-low oxygen conditions-on embryonic heart development, specifically on heart size and blood flow velocities as markers of further defects.These early markers can be associated with later defects that come from these conditions, and explore the implications of hypoxia in all species' development.Fertilized chicken eggs (Gallus gallus domesticus) wrapped in clay and aluminum foil were used to model hypoxic embryo conditions.Each egg was incubated until approximately HH31 (day 7) or approximately HH35 (day 9).Then each egg was windowed, imaged using an ultrasound (Vevo 2100), dissected, weighed, and imaged under a microscope.We used the Doppler ultrasound feature of the Vevo 2100 system to determine flow velocity along the heart outflow tract.ImageJ was used to find the lengths and widths of the hearts from microscopic images by calibrating the size of the heart to the size of a known object, in our case, a 0.385 mm wide wire.Our results show that embryos that developed in hypoxic conditions had both larger hearts and faster cardiac blood flow velocities than control embryos, demonstrating that development in hypoxic conditions leads to abnormal development-an enlarged heart and faster blood flow-that perhaps can be projected onto humans.