Small molecule screening platform for assessment of cardiovascular toxicity on adult zebrafish heart

Adult zebrafish were anesthetized and after rapid decapitation the hearts were isolated. The short time required for isolation of hearts allows dissection of multiple fishes, thereby obtaining a large sample size. The simple protocol for ex vivo culture allowed maintaining the beating heart for several days. The in-house developed script and spectral analyses allowed the readouts to be presented either in time domain or in frequency domain. Taken together, the current report offers an efficient platform for performing cardiac drug testing and pharmacological screens.The new methodology presents a fast, cost-effective, sensitive and reliable method for performing small molecule screening. The variety of readouts that can be obtained along with the in-house developed analyses script offers a powerful setup for performing cardiac toxicity evaluation by researchers from both academics and industry.The drug discovery process is heavily impeded by cardiovascular toxicity [1]. The sooner toxicity is discovered, the better for preclinical safety standards and cost of drug development. Various in vitro assays such as membrane potential dyes [2], rubidium efflux [3], radioligand binding [4] and patch clamp [5] have been used to identify compounds displaying cardiac toxicity. Since a compound can affect more than one target, it is necessary to understand the effects on the whole organ system. Therefore, various ex vivo assays such as the purkinje fiber assay [6], isolated heart assay [7] and in vivo assay using transgenic mice [8] have emerged. However, these assays are limited in specificity, reliability and throughput efficiency. Thus, more model systems are needed to evaluate cardiovascular toxicity.Zebrafish has gained immense popularity as a model for small molecule screening for factors influencing the cardiovascular system [9-11]. Various screens have been performed on zebrafish embryos and larvae to study factors influencing development and homeostasis of the cardiovas