Using the tentacle extract (TE) from the jellyfish Cyanea capillata,we have previously established a delayed jellyfish enomatiovenn syndrome (DJES) model,which is meaningful for clinical interventions against jellyfish stings.However,the mechanism of DJES still remains unclear.Thus,this study aimed to explore its potential mechanism by detecting TE-induced microvasculature alterations in vivo and ex vivo.Using a third-generation synchrotron radiation facility,we,for the first time,directly observed the blood vessel alterations induced by jellyfish venom in vivo and ex vivo.Firstly,microvasculature imaging of whole-body mouse in vivo indicated that the small blood vessel branches in the liver and kidney in the TE-treated group,especially the distal small blood vessels in the kidney,seemed much thinner than those in the control group.Secondly,3D imaging of kidney ex vivo showed that the kidneys in the TE-treated group had incomplete vascular trees where distal vessel branches were partly missing and disorderly disturbed.Finally,histopathological analysis found that obvious morphological changes,especially hemorrhagic effects,were also present in the TE-treated kidney.Thus,TE-induced microvasculature changes might be one of the important mechanisms of multiple organ dysfunctions in DJES.In addition,the methods we employed here will probably facilitate further studies on developing effective therapeutic strategies against DJES.