Description

Product Description

Pentetreotide is a synthetic peptide conjugated with diethylenetriaminepentaacetic acid (DTPA), engineered to facilitate chelation with radioisotopes such as indium-111 for molecular imaging applications. Functionally, it mimics the pharmacological properties of somatostatin, a natural peptide hormone that inhibits the release of various growth and neuroendocrine factors.

By radiolabeling Pentetreotide with indium, researchers can visualize and quantify somatostatin receptor expression in vivo through single-photon emission computed tomography (SPECT). This technique provides critical insights into tumor localization, receptor density, and metastatic spread, particularly in neuroendocrine tumors (NETs) such as carcinoid tumors, gastrinomas, and insulinomas.

The peptide’s high affinity for somatostatin receptor subtypes 2 and 5 (SSTR2 and SSTR5) underpins its imaging precision. This receptor selectivity allows researchers to map receptor distribution in various tissues, evaluate receptor internalization kinetics, and assess the biological behavior of receptor-positive malignancies.

Structurally, Pentetreotide retains the cyclic octapeptide backbone of Octreotide but incorporates a DTPA moiety at its N-terminus. This chelating group stably binds metallic radioisotopes, enabling controlled synthesis of radiopharmaceutical derivatives. The molecule’s physicochemical stability and receptor affinity make it an ideal candidate for studying peptide-based radiotracers and somatostatin receptor pharmacology.

In addition to its use in nuclear imaging, Pentetreotide serves as a valuable biochemical probe for receptor-binding assays and ligand competition studies. It has facilitated key discoveries regarding receptor trafficking, endocytosis, and ligand-dependent desensitization processes within neuroendocrine cell lines.

Pentetreotide’s robust in vivo binding characteristics and minimal non-specific uptake enhance imaging clarity and quantification accuracy. It also provides a foundation for developing newer radioligands and somatostatin-based diagnostic tracers with improved pharmacokinetics and imaging contrast.

Through its reproducible binding affinity and radiochemical stability, Pentetreotide continues to be indispensable for preclinical and translational research into receptor-targeted imaging strategies.

Product Specifications

Mechanism of Action

Pentetreotide functions as a receptor-specific imaging probe through its high-affinity binding to somatostatin receptors (SSTRs). Upon administration, the radiolabeled peptide selectively binds to SSTR-positive cells, particularly those overexpressing SSTR2 and SSTR5, which are prevalent in neuroendocrine tumors.

Following receptor engagement, the peptide–receptor complex undergoes internalization into the tumor cell, concentrating the radiolabeled signal and allowing for clear imaging via SPECT or planar scintigraphy. This internalization enhances image resolution and enables quantitative receptor mapping.

The DTPA moiety in Pentetreotide acts as a versatile chelating agent, forming stable coordination complexes with trivalent metal ions such as indium (In³⁺). The resulting [¹¹¹In]-Pentetreotide complex exhibits excellent in vivo stability, ensuring that the radiolabel remains intact during biodistribution and imaging.

By exploiting somatostatin receptor overexpression, Pentetreotide provides a receptor-mediated imaging approach distinct from non-specific tracers. This specificity allows precise detection of primary tumors and metastatic lesions, especially in tissues such as the pancreas, gastrointestinal tract, and lungs.

In mechanistic studies, Pentetreotide also aids in understanding receptor-ligand kinetics, receptor recycling, and signal modulation. It reveals how somatostatin analogs inhibit adenylate cyclase activity, reduce calcium influx, and suppress secretion of neuroendocrine hormones—all crucial to tumor cell regulation.

Overall, Pentetreotide’s mechanism combines receptor-specific binding, stable radionuclide chelation, and efficient intracellular trafficking, making it a key molecule for advanced imaging and receptor research.

Side Effects

In preclinical and translational research settings, Pentetreotide has shown favorable tolerability and minimal cytotoxicity when used at experimental concentrations.

Potential observed side effects in model systems include transient receptor desensitization, mild gastrointestinal activity modulation, and minor metabolic alterations due to somatostatin receptor interactions. These effects are generally reversible upon compound clearance.

At supra-physiological doses, Pentetreotide may transiently alter calcium-dependent signaling or hormone secretion in neuroendocrine cell lines. However, these phenomena are rare under typical research dosages and are well-characterized within receptor pharmacology frameworks.

No genotoxic or mutagenic effects have been reported. When properly handled and stored, Pentetreotide maintains high chemical stability without degradation byproducts that could interfere with assay integrity.

As with all research peptides, appropriate handling, shielding from radiation exposure (for radiolabeled forms), and compliance with laboratory safety standards are mandatory.

Disclaimer

 is supplied strictly for laboratory research use only. It is not intended for human or veterinary applications, clinical diagnostics, or therapeutic use.

Keywords

 CAS 138661-02-6, DTPA-Octreotide, radiolabeled somatostatin analog, neuroendocrine tumor imaging, somatostatin receptor tracer, nuclear medicine research, SSTR imaging compound, indium-111 conjugate, receptor binding peptide

Shipping Guarantee

All peptides are packaged in temperature-controlled containers and shipped under validated cold-chain logistics to ensure chemical stability and purity upon arrival.

Trade Assurance

Each batch of Pentetreotide is verified by HPLC and mass spectrometry. Certificates of Analysis (CoA) are available upon request to confirm identity, purity, and peptide integrity.