Laser-scanning velocimetry: a confocal microscopy method for quantitative measurement of cardiovascular performance in zebrafish embryos and larvae.
BACKGROUND
The zebrafish Danio rerio is an important model system for drug discovery and to study cardiovascular development. Using a laser-scanning confocal microscope, we have developed a non-invasive method of measuring cardiac performance in zebrafish embryos and larvae that obtains cardiovascular parameters similar to those obtained using Doppler echocardiography in mammals. A laser scan line placed parallel to the path of blood in the dorsal aorta measures blood cell velocity, from which cardiac output and indices of vascular resistance and contractility are calculated.


RESULTS
This technique, called laser-scanning velocimetry, was used to quantify the effects of pharmacological, developmental, and genetic modifiers of cardiac function. Laser-scanning velocimetry was applied to analyze the cardiovascular effects of morpholino knockdown of osmosensing scaffold for MEKK3 (OSM), which when mutated causes the human vascular disease cerebral cavernous malformations. OSM-deficient embryos had a constricted aortic arch and markedly increased peak cell velocity, a characteristic indicator of aortic stenosis.


CONCLUSIONS
These data validate laser-scanning velocimetry as a quantitative tool to measure cardiovascular performance for pharmacological and genetic analysis in zebrafish, which requires no specialized equipment other than a laser-scanning confocal microscope.
Malone
Michael H
MH
Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. michael_malone@med.unc.edu
Sciaky
Noah
N
Stalheim
Lisa
L
Hahn
Klaus M
KM
Linney
Elwood
E
Johnson
Gary L
GL
D062365:Aminobenzoates / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000196:embryology / Q000502:physiology; D001783:Blood Flow Velocity / Q000187:drug effects; D015153:Blotting, Western; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D005816:Genetic Complementation Test; D006321:Heart / Q000196:embryology / Q000502:physiology*; D007814:Larva / Q000166:cytology / Q000235:genetics / Q000502:physiology; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D008845:Microinjections; D018613:Microscopy, Confocal / Q000379:methods*; D009025:Morpholines / Q000494:pharmacology; D009154:Mutation; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D015027:Zebrafish / Q000196:embryology / Q000502:physiology*
D062365:Aminobenzoates; D008840:Microfilament Proteins; D009025:Morpholines; D012333:RNA, Messenger; C003636:tricaine