American Society of Hirudotherapy

Leech Nitric Oxide Synthase Modulator

Modulates host NOS activity at bite site — contributes to vasodilation phase of feeding.

Preclinical / mechanisticLast updated: 2026-05-26 · Reviewed by ASH Editorial Board
Molecular weight of Leech Nitric Oxide Synthase Modulator compared with other characterized leech-derived compoundsHementerin80 kDaHementin80 kDaHementin-Like Protein (HLP-1)80 kDaLeech Collagenase70 kDaHaemadipsa yanyuanensis Progr…70 kDaLeech Apyrase67 kDaCalin65 kDaHyaluronidase60 kDaAntithrombin III binding prot…58 kDaCollagenolytic Fibrinolysin55 kDaLeech Thrombospondin-Like Pro…50 kDaLeech Nitric Oxide Synthase M…22 kDa
Molecular weight (kilodaltons) of Leech Nitric Oxide Synthase Modulator (highlighted) alongside other characterized leech salivary compounds. Smaller proteins/peptides generally diffuse and act faster.

Mechanistic Evidence Box

Preclinical / mechanistic
Page type
Compound profile
Evidence type
Modulates host NOS activity at bite site — contributes to vasodilation phase of feeding.
Evidence level
Mechanistic discussion
Drug vs leech
Leech-derived crude extract

Clinical translation limit

The vasodilatory role of leech NOS modulation at the bite site is mechanistic only and does not establish clinical efficacy for any vasodilation-related indication. No FDA-approved derivative exists.

Molecular Profile

Category
Vasodilator
Evidence tier
Preclinical
Molecular weight
22,000 Da
Source species
Hirudo medicinalis
Leech Nitric Oxide Synthase Modulator molecular structure

Biological Targets

  • → nitric oxide synthase (NOS) pathway

External Resources

    Related Vasodilator Compounds

    Leech Histamine-like Vasodilator

    Histamine-receptor-acting compound — contributes to local vasodilation at feeding site.

    Leech Acetylcholine

    Cholinergic vasodilator contributing to feeding-site vascular dilation.

    Leech Bradykinin Modulator

    Salivary factor reported to modulate the bradykinin / kinin-kallikrein vasoactive cascade.

    Shuxuetong (SXT) Injection Active Peptides

    Three angiogenic peptides (DSYVGDEAQSKR, YNELRVAPEEHP, IQFLPEGSPVTM) from a leech + earthworm Shuxuetong (SXT) injection — Sun 2022 hindlimb-ischemia model.

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    This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.