The endothelin-1 pathway and the development of cardiovascular defects in the haemodynamically challenged chicken embryo.
OBJECTIVE
Ligating the right lateral vitelline vein of chicken embryos (venous clip) results in cardiovascular malformations. These abnormalities are similar to malformations observed in knockout mice studies of components of the endothelin-1 (ET-1)/endothelin-converting enzyme-1/endothelin-A receptor pathway. In previous studies we demonstrated that cardiac ET-1 expression is decreased 3 h after clipping, and ventricular diastolic filling is disturbed after 2 days. Therefore, we hypothesise that ET-1-related processes are involved in the development of functional and morphological cardiovascular defects after venous clip.


METHODS
In this study, ET-1 and endothelin receptor antagonists (BQ-123, BQ-788 and PD145065) were infused into the HH18 embryonic circulation. Immediate haemodynamic effects on the embryonic heart and extra-embryonic vitelline veins were examined by Doppler and micro-particle image velocimetry. Ventricular diastolic filling characteristics were studied at HH24, followed by cardiovascular morphologic investigation (HH35).


RESULTS
ET-1 and its receptor antagonists induced haemodynamic effects at HH18. At HH24, a reduced diastolic ventricular passive filling component was demonstrated, which was compensated by an increased active filling component. Thinner ventricular myocardium was shown in 42% of experimental embryos.


CONCLUSIONS
We conclude that cardiovascular malformations after venous clipping arise from a combination of haemodynamic changes and altered gene expression patterns and levels, including those of the endothelin pathway.
Groenendijk
Bianca C W
BC
Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands.
Stekelenburg-de Vos
Sandra
S
Vennemann
Peter
P
Wladimiroff
Juriy W
JW
Nieuwstadt
Frans T M
FT
Lindken
Ralph
R
Westerweel
Jerry
J
Hierck
Beerend P
BP
Ursem
Nicolette T C
NT
Poelmann
Robert E
RE
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000235:genetics / Q000378:metabolism; D001783:Blood Flow Velocity; D002302:Cardiac Output; D018376:Cardiovascular Abnormalities / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D002478:Cells, Cultured; D002642:Chick Embryo; D004452:Echocardiography; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1 / Q000235:genetics / Q000378:metabolism*; D000072396:Endothelin-Converting Enzymes; D018507:Gene Expression Regulation, Developmental; D006321:Heart / Q000196:embryology / Q000503:physiopathology*; D006339:Heart Rate; D006439:Hemodynamics / Q000187:drug effects; D017078:Laser-Doppler Flowmetry; D008026:Ligation; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D009842:Oligopeptides / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D017466:Receptors, Endothelin / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014680:Veins / Q000503:physiopathology / Q000601:surgery; D016276:Ventricular Function; D015017:Yolk Sac / Q000098:blood supply*
D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D009842:Oligopeptides; D010456:Peptides, Cyclic; D010880:Piperidines; D012333:RNA, Messenger; D017466:Receptors, Endothelin; C082887:PD 145065; C086539:BQ 788; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; C000606925:Ece1 protein, mouse; D000072396:Endothelin-Converting Enzymes; C072247:cyclo(Trp-Asp-Pro-Val-Leu)