Ventricular function and morphology in chick embryo from stages 18 to 29

Area of Science:

• Cardiovascular Physiology
• Developmental Biology
• Embryology

Background:

• The developing chick embryo provides a valuable model for studying cardiac development and function.
• Understanding the normal physiological and morphological changes in the embryonic heart is crucial for identifying developmental abnormalities.

Purpose of the Study:

• To characterize the developmental trajectory of ventricular function and morphology in the chick embryo.
• To correlate hemodynamic parameters with changes in myocardial myocyte organelle composition during development.

Main Methods:

• Measurements included wet/dry ventricular and embryo weights, ventricular pressure (phasic, dP/dt), and dorsal aortic velocity (phasic, mean, dV/dt) using servo null and pulsed-Doppler systems.
• Myocardial myocyte organelle composition (myofibrils, mitochondria) was analyzed using volumetric analysis.
• Data were collected across various developmental stages (e.g., stage 18 to 29) in chick embryos.

Main Results:

• Ventricular and embryo weights increased geometrically, but the ventricle-to-embryo weight ratio decreased significantly during development.
• Ventricular systolic and end-diastolic pressures, as well as dP/dt, showed marked increases from stage 18 to 29.
• Dorsal aortic velocity (dV/dt) also increased, while myocyte myofibril volume percentage peaked at stage 27 and declined by stage 29; mitochondrial volume remained constant.

Conclusions:

• These findings establish normative data for chick embryo ventricular function and morphology.
• The study highlights dynamic changes in cardiac hemodynamics and myocyte composition during embryonic development.
• This provides a baseline for future research into cardiac development and disease models.