SP(Substance P) ELISA Kit (E-EL-0067)

This ELISA kit uses the Competitive-ELISA principle. The micro ELISA plate provided in this kit has been pre-coated with Universal SP. During the reaction, Universal SP in the sample or standard competes with a fixed amount of Universal SP on the solid phase supporter for sites on the Biotinylated Detection Ab specific to Universal SP. Excess conjugate and unbound sample or standard are washed away, and Avidin-Horseradish Peroxidase (HRP) conjugate are added to each micro plate well and incubated. Then a TMB substrate solution is added to each well. The enzyme-substrate reaction is terminated by the addition of stop solution and the color turns from blue to yellow. The optical density (OD) is measured spectrophotometrically at a wavelength of 450 nm ± 2 nm. The concentration of Universal SP in tested samples can be calculated by comparing the OD of the samples to the standard curve.

Substance P (SP) is an eleven-amino-acid peptide of the tachykinin family generated by proteolytic processing of the product of the TAC1 gene and closely related to neurokinin A. It is distributed in the central and peripheral nervous systems, particularly in unmyelinated sensory C-fiber terminals, in the spinal dorsal horn, in enteric neurons and in the intestinal mucosa, where it acts as a neurotransmitter and a local mediator of neurogenic responses. As the preferred ligand of the neurokinin-1 receptor (NK1R), substance P activates phospholipase C and mobilizes intracellular calcium, thereby transmitting and amplifying nociceptive signals in the spinal dorsal horn. As a mediator of neurogenic inflammation it promotes vasodilation and plasma extravasation, activates mast cells, recruits immune cells and sensitizes nociceptors. Measurement of substance P supports research on pain, itch and inflammation. The pathway is a therapeutic target in chemotherapy-induced nausea and vomiting, where NK1R antagonists are used, and levels rise in arthritis, asthma, inflammatory bowel disease and migraine. Quantitation in serum, plasma, tissue and cerebrospinal fluid helps evaluate NK1R-directed interventions and neuroimmune activity.