Description

1. Product Description 

Saralasin acetate hydrate (CAS 39698-78-7) is a synthetic octapeptide analog of angiotensin II developed to study the renin–angiotensin–aldosterone system (RAAS). Known chemically as [Sar¹,Ala?] Angiotensin II, this analog functions as a competitive angiotensin II receptor antagonist while exhibiting partial agonist activity, making it an invaluable research tool in hypertension and cardiovascular studies.

Scientific Background

The RAAS system plays a crucial role in regulating blood pressure, fluid balance, and vascular resistance. Angiotensin II, an octapeptide hormone, exerts potent vasoconstrictive and aldosterone-stimulating effects through activation of the angiotensin II receptor (AT1). Dysregulation of RAAS contributes to hypertension, renal disorders, and cardiovascular disease.

Saralasin acetate hydrate was one of the first synthetic angiotensin II antagonists, enabling researchers to probe RAAS-mediated pathophysiology decades before small-molecule AT1 receptor blockers were developed.

Mechanistic Importance

• Competitive Antagonism: Saralasin binds to angiotensin II receptors with high affinity (Ki = 0.32 nM for 74% of binding sites).

• Partial Agonism: While predominantly an antagonist, Saralasin also demonstrates weak receptor activation in some systems.

• Experimental Use: Its dual profile allows the dissection of angiotensin II receptor function in normal physiology and disease models.

Research Significance

Saralasin acetate hydrate remains an important agent for:

• Studying renovascular hypertension models.

• Investigating renin-dependent (angiotensinogenic) hypertension.

• Exploring receptor pharmacology and competitive binding dynamics.

• Serving as a reference peptide for novel RAAS-targeting therapeutics.

Its historical and ongoing use in preclinical research underlines its continued relevance as a benchmark angiotensin receptor antagonist peptide.

2. Product Specifications 

3. Mechanism of Action & Research Applications

Mechanism of Action

Saralasin acetate hydrate binds to angiotensin II receptors and acts primarily as a competitive antagonist. By occupying receptor binding sites, it blocks angiotensin II from inducing vasoconstriction and aldosterone release. Its Ki of 0.32 nM for 74% of receptor sites reflects high affinity.

However, unlike full antagonists, Saralasin exhibits partial agonist activity, producing weak receptor activation under certain experimental conditions. This unique pharmacological profile makes it particularly valuable for:

• Distinguishing receptor subtypes.

• Investigating dose-dependent antagonism and partial agonism.

• Modeling transitional states between receptor inhibition and activation.

Research Applications

1. Hypertension Research

   • Saralasin was the first peptide antagonist used to confirm RAAS involvement in renovascular hypertension.

   • It provides a tool to evaluate blood pressure regulation in preclinical models.

2. Renin-Dependent Hypertension Studies

   • By competitively blocking angiotensin II, Saralasin reveals the dependence of certain hypertensive states on renin activity.

3. Receptor Pharmacology

   • Ideal for binding assays and receptor activation/inhibition profiling.

   • Useful in mapping receptor binding dynamics in cardiovascular tissues.

4. Comparative Studies

   • Serves as a benchmark peptide antagonist for comparison with modern AT1 blockers (losartan, valsartan, etc.).

   • Helps elucidate the differences between peptide-based and small-molecule antagonists.

5. Translational Research

   • While not intended for therapeutic use, Saralasin provides insights into mechanisms underlying hypertension therapies.

   • It contributed historically to the development of next-generation antihypertensive agents.

     

4. Side Effects (Research Reference) 

In preclinical and early experimental use, Saralasin acetate hydrate demonstrated several effects:

• Blood pressure variability: As a partial agonist, Saralasin can sometimes lower or raise blood pressure depending on dose and model.

• Vascular responses: May cause transient vasodilation or paradoxical vasoconstriction.

• Hormonal modulation: Influences aldosterone secretion and renin activity in experimental systems.

• Species-dependent effects: Rodent and primate models may show different hemodynamic responses.

• Storage stability: Repeated freeze-thaw cycles reduce peptide integrity, potentially altering results.

All observed effects are research-only findings. Saralasin acetate hydrate is not for clinical or veterinary use.

5. Disclaimer

For laboratory research use only. Not for human or veterinary use.

6. Keywords

• Saralasin acetate hydrate

• Saralasin CAS 39698-78-7

• [Sar1,Ala8] Angiotensin II

• Angiotensin II receptor antagonist peptide

• Competitive angiotensin II antagonist research

• Renovascular hypertension peptide model

• Renin-dependent hypertension research peptide

• GMP peptide supplier Saralasin

• Octapeptide angiotensin II analog

• RAAS experimental peptide antagonist