Tissue kallikrein (human urinary kallidinogenase) (HUK)

Human urinary kallidinogenase is a glycoprotein serine protease derived from human urine, belonging to the tissue kallikrein family. It catalyzes the conversion of kininogen to active kinins, promoting vasodilation, neuroprotection, angiogenesis, and improved cerebral perfusion via the kallikrein–kinin system. Approved in China for treating acute ischemic stroke, its clinical utility centers on reducing neurological damage and recurrence risk by suppressing inflammation and apoptosis, enhancing microvascular growth, and improving functional recovery. Its effects are mediated primarily through activation of bradykinin B1 and B2 receptors, and it is being explored for other vascular and inflammatory diseases. Large-scale safety and efficacy data are limited, with ongoing clinical trials seeking further validation.

Other names

human urinary kallidinogenasetissue kallikreinkallikrein-1urokallikrein

Enzymatic hydrolysis of kininogen to release kinins (bradykinin, kallidin), which act via bradykinin B1/B2 receptors to relax vascular smooth muscle and promote vasodilation, angiogenesis, and neuroprotection