Ischemic/hypoxic injury significantly damages vascular function, detrimentally im-pact-ing patient outcomes. Changes in mitochondrial structure and function are closely associated with ischemia/hypoxia-induced vascular dysfunction. The mecha-nism of this process remains elusive. Using rat models of ischemia and hypoxic vas-cular smooth muscle cells (VSMCs), we combined transmission electron microscopy, super-resolution microscopy, and metabolic analysis to analyze the structure and function change of mitochondrial cristae. Multi-omics approaches revealed arginase 1 (Arg1) upregulation in ischemic VSMCs, confirmed by in vivo and in vitro knock-out models showing Arg1's protective effects on mitochondrial cristae, mitochondrial and vascular function, and limited the release of mtDNA. Mechanistically, Arg1 in-teracting with Mic10 led to mitochondrial cristae remodeling, together with hypox-ia-induced VDAC1 lactylation resulting in the opening of MPTP and release of mtDNA of VSMCs. The released mtDNA led to PANoptosis of VSMCs via activation of the cGAS-STING pathway. ChIP-qPCR results demonstrated that lactate-mediated Arg1 up-regulation was due to H3K18la upregulation. VSMCs targeted nano-material PLGA-PEI-siRNA@PM-α-SMA (NP-siArg1) significantly improved vascular dysfunction. This study uncovers a new mechanism of vascular dysfunction following ischemic/hypoxic injury: a damaging positive feedback loop mediated by lactate-regulated Arg1 expression between the nucleus and mitochondria, leading to mitochondria cristae disorder and mtDNA release, culminating in VSMCs PANopto-sis. Targeting VSMCs Arg1 inhibition offers a potential therapeutic strategy to alle-viate ischemia/hypoxia-induced vascular impairments