Pre mixed peptide pens are a convenient way to administer peptides. They come with a pen case, needles, and a cartridge with your chosen peptide pre-mixed inside. They are easy to use, more accurate, and much safer than using a vial and syringe. They are also easier to carry around, which is great for people who travel. The pens are available in various strengths, and individual cartridges can be purchased separately to top up the kit.
The first peptide therapeutic was insulin, which was developed more than 100 years ago to treat diabetes mellitus. Since then, the industry has been working on formulations to improve bioavailability and patient adherence.
These peptides typically bind to GPCRs (G-protein-coupled receptors) and activate signaling through heterotrimeric G protein / complexes, which are stimulated by guanine nucleotide exchange of GDP for GTP and inactivated by autocatalytic GTPase activity and reassociation with the bg heterodimer (Fig. 1A).
Among the GPCRs identified as PEN targets in the brain, mGPR83 is highly expressed in the hypothalamus and responds to the proSAAS precursor PEN (Fig. 1A). To evaluate mPEN binding to mGPR83, we used an assay in which HA-tagged mGPR83 was labeled on the surface of cells. Exposure to mPEN caused rapid and robust internalization of mGPR83 in a dose-dependent manner, as demonstrated by ELISA (Fig. S6B).
We next tested the effect of mPEN on evoked EPSCs in Neuro2A cells and found that it significantly inhibited GPCR-coupled PLC activity in a concentration-dependent manner. mPEN also activated the MAPK pathway, as measured by increased phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2).