Hemodynamics of the Stage 12 to Stage 29 Chick Embryo

• Published in: Circulation research 1989-12, Vol.65 (6), p.1665-1670
• Main Authors: Hu, Norman, Qark, Edward B
• Format: Article
• Language: English
• Subjects: Animals; Aorta - embryology; Biological and medical sciences; Blood Pressure; Cardiac Output; Chick Embryo; Embryology: invertebrates and vertebrates. Teratology; Fundamental and applied biological sciences. Psychology; Heart - embryology; Heart Ventricles - embryology; Hemodynamics; Organogenesis. Fetal development; Organogenesis. Physiological fonctions; Regional Blood Flow; Vascular Resistance
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/01.res.65.6.1665

The heart is the first functioning organ in the embryo and provides blood flow during cardiac morphogenesis from a muscle-wrapped tube a few cells thick to the four-chambered pump. We described the hemodynamics of the chick embryo from stage 12 (50 hours of a 21-day incubation) to stage 29 (6 days), during which the embryo weight increased 120-fold. We measured ventricular, embryo and extraembryonic vascular bed wet weights, dorsal aortic blood flow with a directional pulsed-Doppler velocity meter, and ventricular and vitelline arterial blood pressures witfa a servo-null micropressure system. The data are reported as mean ± SEM. With rapid development and morphogenesis, dorsal aortic blood flow increased from 0.015 ± 0.004 to 2.40 ± 0.20 mm/sec parallel to the geometric increase of wet embryo weight from 2.22 ± 0.10 to 267.5 ± 9.7 mg. Dorsal aortic blood flow normalized for embryo and extraembryonic weight remained relatively constant (Y=2.13+0.02X, r=0.23, SEE=0.03). Stroke volume increased from 0.01 ± 0.003 to 0.69 ± 0.03 mm, and heart rate doubled from 103 ± 2 to 208 ± 5 beats/min. Systolic, diastolic, and mean vitelline arterial pressure increased linearly from 0∼32 ± 0.01, 0.23 ± 0.01, and 0.28 ± 0.01 mm Hg at stage 12 to 2.00 ± 0.06, 1.22 ± 0.03, and 1.51 ± 0.04 mm Hg, respectively, at stage 29. Ventricular peak systolic and end-diastolic pressure increased from 0.95 ± 0.04 and 0.24 ± 0.02 at stage 12 to 3.45 ± 0.10 and 0.82 ± 0.03 at stage 29, respectively. The hemodynamic waveforms were similar to those found in the four-chamber heart of the mature animal. These data are integral to understanding the interrelation of function and form during cardiac development.