Visual Tracking and Organ Targeting of Naja atra and Deinagkistrodon acutus Venoms in Mice

In China, bites caused by the <i>Naja atra</i> and <i>Deinagkistrodona acutus</i> are the most common types of snakebites. While the functional characteristics of the two venom components have been well documented, their in vivo metabolic pathways, target organ distribution patterns, and dynamic pharmacokinetic profiles remain less explored. This study established a murine envenoming model through CY7-SE labeling of <i>Naja atra</i> and <i>Deinagkistrodon acutus</i> venoms. The real-time in vivo absorption and biodistribution of venoms were dynamically monitored via fluorescence imaging, with subsequent proteomic profiling to characterize organ-specific toxin targeting patterns. Gel filtration chromatography and HPLC analyses validated labeling efficiency at ratios of 0.1 mg CY7-SE per 1 mg <i>Naja atra</i> venom and 0.075 mg CY7-SE per 1 mg <i>Deinagkistrodon acutus</i> venom, with electrophoretic confirmation of protein integrity and preserved 740 nm fluorescence excitation. Acute toxicity assays demonstrated no significant difference in LD₅₀ lethality between labeled and native venoms (<i>p</i> > 0.05). The intoxication models revealed species-specific pathophenotypes, i.e., CY7-<i>Naja atra</i> venom induced systemic weakness, tachypnea, and inflammatory necrosis in lung, myocardium, and liver, whereas CY7-<i>Deinagkistrodon acutus</i> venom provoked hemorrhagic diathesis. Both models exhibited marked leukocytosis, transaminitis, and elevated creatinine levels (<i>p</i> < 0.05). Fluorescence tracing uncovered distinct biodistribution kinetics: <i>Deinagkistrodon acutus</i> venom achieved peak organ accumulation at 3 h with rapid dissemination (24 h injection-site retention: 12.61%), contrasting with <i>Naja atra</i> venom's delayed 6 h peak and prolonged renal sequestration (24 h injection-site retention: 60.9%). Target organ proteomic profiling identified <i>Deinagkistrodon acutus</i>-enriched thrombin-like enzymes and metalloproteinases in lung/liver/spleen, while <i>Naja atra</i> venom predominantly accumulated renal acidic phospholipase A₂ and weakly neurotoxic NNAM2.