Multilevel Microdissection and Functional-Structural Profiling of Human Renal Arterial Branches

Renal vascular dysfunction plays a critical role in the pathogenesis of multiple clinical conditions, including acute kidney injury, renal ischemia, and hypertension, presenting significant challenges in clinical management and adversely affecting patient outcomes. The isolation and functional characterization of intrarenal arteries are crucial for elucidating the mechanisms underlying renal vascular dysfunction, particularly related to kidney injury, and guiding targeted therapeutic development. Despite its clinical importance, standardized approaches for isolating and functionally assessing human intrarenal arteries across different branching levels remain underdeveloped. This protocol provides a comprehensive framework for the systematic isolation and multimodal evaluation of intrarenal arterial branches, incorporating functional and structural assessments under both physiological and pathological conditions. The methodology encompasses three key components: (1) precise anatomical identification and microdissection of intrarenal arteries from donor kidneys, accompanied by Hematoxylin-Eosin (H&E) staining for structural confirmation; (2) rigorous normalization procedures in wire myography to enhance measurement reproducibility and reliability; and (3) quantitative analysis of vasomotor responses using precision wire myography techniques. Normalization is based on the muscle length-tension relationship, where incremental stretching of arterial segments establishes an optimal resting tension to maximize actin-myosin overlap, thereby eliciting peak contractile responses. In wire myography, isolated vessel segments are suspended between two parallel wires, allowing precise measurement of vascular tension. By applying rigorous normalization protocols, this technique enables reproducible and reliable quantification of vascular reactivity across diverse pathophysiological conditions and pharmacological interventions.