Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Substance P inhibits carbamylcholine-induced 22Na+ uptake in the clonal cell line PC12. This inhibition is noncompetitive with agonist but competitive with Na+. Octahydrohistrionicotoxin (H8-HTX) also exhibits this same pattern of inhibition. Moreover, both substance P and H8-HTX are very effective in enhancing agonist-induced receptor desensitization. Local anesthetics, such as QX222, also cause inhibition that is competitive with Na+, but they have only marginal effects on desensitization. Because substance P and H8-HTX cannot by themselves cause desensitization, their action is dependent on and synergistic with the action of agonist. Furthermore, substance P and H8-HTX do not appear to compete for the same site as QX222, which is thought to bind to the ion channel. Finally, substance P can stabilize the desensitized state of the receptor even when added subsequent to the actual desensitization and removal of agonist. Thus, substance P does not require open ion channels for binding and may modulate the activity of the receptor-ionophore complex by binding to a distinct regulatory site.
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PMID:Substance P enhances cholinergic receptor desensitization in a clonal nerve cell line. 615 98

Polysorbate 80 is a synthetic nonionic surfactant used as an excipient in drug formulation. Various products formulated with polysorbate 80 are used in the oncology setting for chemotherapy, supportive care, or prevention, including docetaxel, epoetin/darbepoetin, and fosaprepitant. However, polysorbate 80, like some other surfactants, is not an inert compound and has been implicated in a number of systemic and injection- and infusion-site adverse events (ISAEs). The current formulation of intravenous fosaprepitant has been associated with an increased risk of hypersensitivity systemic reactions (HSRs). Factors that have been associated with an increased risk of fosaprepitant-related ISAEs include the site of administration (peripheral vs. central venous), coadministration of anthracycline-based chemotherapy, number of chemotherapy cycles or fosaprepitant doses, and concentration of fosaprepitant administered. Recently, two polysorbate 80-free agents have been approved: intravenous rolapitant, which is a neurokinin 1 (NK-1) receptor antagonist formulated with the synthetic surfactant polyoxyl 15 hydroxystearate, and intravenous HTX-019, which is a novel NK-1 receptor antagonist free of synthetic surfactants. Alternative formulations will obviate the polysorbate 80-associated ISAEs and HSRs and should improve overall management of chemotherapy-induced nausea and vomiting.Funding Heron Therapeutics, Inc.
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PMID:Safety of Polysorbate 80 in the Oncology Setting. 2979 27