Abstract

Calcium signaling in blood vessels regulates their growth, immune response, and vascular tone. Vascular endothelial cells are known to be mechanosensitive, and it has been assumed that this mechanosensation mediates calcium responses to pulsatile blood flow. Here we show that in larval zebrafish, the dominant trigger for vascular endothelial Ca events comes from body motion, not heartbeat-driven blood flow. Through a series of pharmacological and mechanical perturbations, we showed that body motion is necessary and sufficient to induce endothelial Ca events, while neither neural activity nor blood circulation is either necessary or sufficient. Knockout and temporally restricted knockdown of eliminated the motion-induced Ca events. Our results demonstrate that swimming-induced tissue motion is an important driver of endothelial Ca dynamics in larval zebrafish.