Cardiovascular toxicity:

Zebrafish and mammalian hearts exhibit similar functional characteristics, including blood flow directions, a high-pressure system drived by a specialized endocardium musculature, a heart rhythm regulated by an electrical system and a heart beat associated with pacemaker activity. Furthermore, zebrafish pharmacologic responses to well-characterized cardiotoxins are similar to responses in humans. Because zebrafish larvae are virtually transparent, the intention of recent studies has been to concentrate on creating a medium throughput assay based on morphological endpoints of toxicity which are assessable using a transmitted light microscope without the need for dissection, and cardiac functions and cardiovascular toxicity could be visually assessed. 

Hunter has developed the zebrafish model of drug cardiotoxicity assessment. Drug could be administered by soaking, yolk sac and circulation microinjection. Cardiovascular toxicity of test drug in zebrafish could be evaluated using six specific phenotypic endpoints: heart rate, heart rhythm, pericardial edema, circulation, hemorrhage and thrombosis.