Description
Hexarelin Acetate – Advanced Biochemical Mechanism Profile
(Growth Hormone Secretagogue; GHSR-1a Agonist; Peptide Analog)
Hexarelin is a synthetic growth hormone secretagogue (GHS) that selectively activates the GHSR-1a receptor, a G-protein–coupled receptor expressed in pituitary and hypothalamic cell models. It is structurally related to ghrelin mimetics, but engineered for increased receptor affinity and metabolic stability.
✅ 1. Primary Receptor Target
GHSR-1a (Growth Hormone Secretagogue Receptor 1a)
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Class: Gq/11-coupled GPCR
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Location: pituitary somatotrophs, hypothalamus, cardiac tissue, immune cells
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Outcome: stimulation of intracellular Ca²⁺ mobilization and PKC activation
Upon binding:
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GHSR-1a → Gq/11
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Phospholipase Cβ (PLCβ) activation
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PIP₂ → IP₃ + DAG hydrolysis
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IP₃ → Ca²⁺ release from ER stores
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DAG → PKC activation
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Membrane depolarization → GH exocytosis in endocrine studies
✅ 2. Secondary Signaling Pathways
A. cAMP / PKA (Gs-linked cross-activation)
Some cell models show additional Gs coupling:
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↑ adenylate cyclase
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↑ cAMP
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PKA phosphorylation of calcium channels
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Enhanced GH-secretory vesicle fusion
B. ERK1/2 MAPK Pathway
GHSR-1a activation stimulates:
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Ras → Raf → MEK1/2 → ERK1/2
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Upregulation of growth-signaling transcription factors
C. PI3K / Akt Pathway
Cardiac and metabolic research models show:
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PI3K → Akt phosphorylation
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Anti-apoptotic gene signaling
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Mitochondrial membrane stabilization
✅ 3. Second Messengers and Enzymes
| Pathway Component | Effect of Hexarelin |
|---|---|
| PLCβ | Activated |
| IP₃ | ↑ Ca²⁺ mobilization |
| DAG / PKC | Activated |
| cAMP | Increased in some cell types |
| ERK1/2 MAPK | Upregulated |
| PI3K → Akt | Survival signaling |
✅ 4. Gene Targets Commonly Studied in Research
| Functional Area | Gene Targets |
|---|---|
| GH Axis | GHRH, GHRHR, IGF-1, GH1 |
| Calcium & vesicle fusion | CACNA1A, SNARE complex genes |
| Cytoprotection | BCL2, MCL1, SOD2 |
| MAPK-responsive transcription | FOS, JUN, EGR1 |
Certain studies also track cardiac metabolic genes due to GHSR expression in cardiomyocytes.
✅ 5. Receptor Kinetics
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High affinity for GHSR-1a
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Resistant to peptidase degradation relative to native ghrelin
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Sustained intracellular Ca²⁺ activity
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Rapid induction of GH-releasing vesicle exocytosis in pituitary cell lines
Research-Only Use Classification
Hexarelin Acetate is supplied solely for laboratory research and in-vitro experimentation.
It is not approved for human or animal use, consumption, injection, ingestion, therapeutic application, or diagnostic procedures.
