(Thr4,Gly7)-Oxytocin peptide

• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

[Thr4,Gly7]-Oxytocin is a synthetic analog of the neurohypophyseal peptide oxytocin, in which threonine and glycine replace the native amino acids at positions 4 and 7, respectively. This analog retains the ability to bind to oxytocin receptors and, when administered centrally (i.c.v.) in male rats, stimulates nitric oxide (NO) production in the paraventricular nucleus of the hypothalamus (PVN). The increase in NO production is reflected by elevated concentrations of nitrite (NO2−) and nitrate (NO3−) in the PVN dialysate, as measured by in vivo microdialysis. [Thr4,Gly7]-Oxytocin (100 ng i.c.v.) induces an increase in NO2− concentration comparable to that produced by native oxytocin, indicating that the analog is a full agonist at the central oxytocin receptor in this experimental paradigm.

The effects of [Thr4,Gly7]-Oxytocin on NO production in the PVN are specific to its oxytocinergic activity, as they are blocked by the selective oxytocin receptor antagonist d(CH2)5Tyr(Me)-Orn8-vasotocin. This peptide also demonstrates structure–activity relationships similar to oxytocin: the N-terminal portion of the molecule (oxytocin(1–8)) retains activity, while smaller fragments such as oxytocin(1–6) and oxytocin(7–9) are inactive. These findings support the role of [Thr4,Gly7]-Oxytocin as a useful tool for studying oxytocin receptor-mediated NO signaling in the hypothalamus, without direct association with behavioral or physiological endpoints.

• Melis MR, Succu S, Iannucci U, Argiolas A. Oxytocin increases nitric oxide production in the paraventricular nucleus of the hypothalamus of male rats: correlation with penile erection and yawning. Regul Pept. 1997 Mar 26;69(2):105-11. doi: 10.1016/s0167-0115(97)00002-5. PMID: 9178353.

Trifluoroacetic acid (TFA) is a common counterion from the purification process using High-Performance Liquid Chromatography (HPLC). The presence of TFA can affect the peptide's net weight, appearance, and solubility.

Impact on Net Weight: The TFA salt contributes to the total mass of the product. In most cases, the peptide content constitutes >80% of the total weight, with TFA accounting for the remainder.

Solubility: TFA salts generally enhance the solubility of peptides in aqueous solutions.

In Biological Assays: For most standard in vitro assays, the residual TFA levels do not cause interference. However, for highly sensitive cellular or biochemical studies, please be aware of its presence.