Vasopressin (Arginine Vasopressin) Technical Specification Sheet

Molecular Properties

Parameter Value
Chemical Name Arginine Vasopressin / Antidiuretic Hormone (ADH) / Argipressin
Amino Acid Sequence Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-Gly-NH₂ (disulfide bridge: Cys1-Cys6)
Molecular Formula C₄₆H₆₅N₁₅O₁₂S₂
Molecular Weight 1084.23 g/mol
CAS Number 113-79-1
Sequence Length 9 amino acids (cyclic nonapeptide with 6-membered ring)
Receptor Targets V1a, V1b (V3), V2 receptors; secondary affinity for oxytocin receptor

Physical Properties

Property Specification
Appearance White to off-white lyophilized powder
Solubility Soluble in water, dilute acetic acid, or saline at ≥1 mg/mL; pH 3.5-5.5
pH (1% solution) 3.5 - 5.5 (acidic for stability)
Hygroscopicity Moderate; desiccated storage required
Solution Stability Stable at 4°C for 7-10 days at pH 3.5-5.5; degrades at neutral/alkaline pH

Analytical Specifications

Test Specification
HPLC Purity ≥98.0%
Mass Spectrometry Confirmed [M+H]⁺ = 1084.23 ± 0.5 Da; disulfide bridge intact
Peptide Content ≥95% (by amino acid analysis)
Disulfide Bond Integrity ≥98% (confirmed by mass spec and biological activity)
Endotoxin Level <1.0 EU/mg
Acetate Content ≤5%
Water Content ≤5% (Karl Fischer)

Storage Parameters

Condition Specification
Lyophilized Storage -20°C to -80°C, desiccated, protected from light
Lyophilized Shelf Life 36 months when stored properly
Reconstituted Storage 2-8°C for up to 10 days at pH 3.5-5.5; -20°C for up to 3 months
Reconstitution Protocol Add 1.0 mL sterile water or 0.1M acetic acid to 1 mg vial; vortex gently 30 seconds
Freeze-Thaw Cycles Maximum 3 cycles; single-use aliquots recommended
Light Sensitivity Moderate; store in amber vials and protect from direct light

Research Dosing Reference

Application Typical Dose Range Frequency Route
In Vitro Cell Studies 1-1000 nM Acute or chronic exposure Culture media
Small Animal Models (Rodent) 0.1-5 μg/kg (antidiuretic); 0.5-10 μg/kg (pressor) Single bolus or infusion IV, SC, IP
Water Retention Studies (V2) 0.1-1 μg/kg Single dose or continuous infusion IV preferred
Vascular Studies (V1a) 1-10 μg/kg Acute bolus IV bolus
Behavioral/Stress Studies 0.5-5 μg/animal (intranasal); 0.1-1 μg/kg (IV) Single dose 30-60 min pre-testing Intranasal or IV
Note: Dosing information is for research reference only. Vasopressin is intended strictly for laboratory research. USP activity typically expressed as Units (U); 1 mg ≈ 400-500 USP units.

Key Research Studies

Year Study Focus Key Findings
1954 Structure elucidation and synthesis Du Vigneaud determined vasopressin structure; differs from oxytocin by 2 amino acids (positions 3 and 8); Cys1-Cys6 disulfide bridge essential for activity; synthesized with full biological potency
1992-1994 Receptor subtype cloning Identified three receptor subtypes: V1a (vascular smooth muscle, liver), V1b/V3 (pituitary corticotrophs), V2 (renal collecting duct); differential Kd values: V1a ~1 nM, V1b ~1.5 nM, V2 ~0.5 nM
2005 Central nervous system effects on social behavior Brain V1a receptor activation modulated social recognition, aggression, pair bonding in rodent models; species-specific V1a receptor expression patterns correlated with monogamous vs polygamous behavior
2010 Structure-activity relationships across receptor subtypes Position 8 (Arg) critical for V2 selectivity; position 3 (Phe) enhances V1 selectivity vs oxytocin receptor; C-terminal Gly-NH₂ absolutely required with removal reducing potency >1000-fold

Mechanism of Action

Biological Pathway Description
V1a Receptor (Vascular) Gq-coupled → PLC → IP₃/DAG → Ca²⁺ mobilization → vascular smooth muscle contraction → vasoconstriction and blood pressure elevation
V1b Receptor (Pituitary) Gq-coupled on anterior pituitary corticotrophs → ACTH release → modulation of HPA axis and stress response
V2 Receptor (Renal) Gs-coupled on collecting duct principal cells → cAMP/PKA → aquaporin-2 insertion into apical membrane → water reabsorption (antidiuretic effect)
Central Effects Modulates social recognition, circadian rhythms, temperature regulation, stress response; V1a receptors in lateral septum, hippocampus, amygdala
Half-Life 5-20 minutes (IV); metabolized by vasopressinases (aminopeptidases) in liver and kidney

Receptor Selectivity Profile

Receptor Binding Affinity (Kd) Primary Tissue/Location Signaling Pathway
V1a 0.5-2 nM Vascular smooth muscle, liver, CNS Gq → PLC → Ca²⁺
V1b (V3) 1-3 nM Anterior pituitary (corticotrophs), CNS Gq → PLC → Ca²⁺
V2 0.3-1 nM Kidney collecting duct, endothelium Gs → adenylyl cyclase → cAMP
Oxytocin Receptor 50-500 nM (low affinity) Uterus, mammary, CNS Gq → PLC → Ca²⁺

Quality Control Parameters

Test Method Acceptance Criteria
Appearance (visual) White to off-white powder; no aggregation or discoloration
Disulfide Bridge Confirmation ESI-MS shows intact cyclic structure; no reduced form detected
RP-HPLC (purity) Main peak ≥98.0%; no single impurity >0.5%
Biological Activity (USP) ≥400 USP units/mg (rat pressor assay)
Amino Acid Analysis Confirmed sequence with Arg at position 8

Comparative Structural Analysis

Position Oxytocin Vasopressin Functional Impact
1 Cys Cys Disulfide bridge formation
2 Tyr Tyr Receptor binding
3 Ile Phe V1 receptor selectivity
6 Cys Cys Disulfide bridge formation
8 Leu Arg V2 receptor selectivity; antidiuretic activity
9 Gly-NH₂ Gly-NH₂ Essential for all activity

External References

1. du Vigneaud V, et al. The sequence of amino acids in oxytocin, with a proposal for the structure of oxytocin. J Biol Chem. 1953;205(2):949-57. https://www.jbc.org/article/S0021-9258(18)49238-1/fulltext

2. Thibonnier M, et al. The basic and clinical pharmacology of nonpeptide vasopressin receptor antagonists. Annu Rev Pharmacol Toxicol. 2001;41:175-202. https://www.annualreviews.org/doi/10.1146/annurev.pharmtox.41.1.175

3. National Center for Biotechnology Information. PubChem Compound Summary for Vasopressin. https://pubchem.ncbi.nlm.nih.gov/compound/Vasopressin

Disclaimer: This product is intended for research use only. Not for human or veterinary diagnostic or therapeutic use. Vasopressin is a potent vasoactive peptide; handle with appropriate laboratory protocols.