Substance P (SP) (SP)

Substance P is an 11-amino acid neuropeptide belonging to the tachykinin family, primarily synthesized in the cell bodies of primary sensory neurons and transported to peripheral and central terminals [1]. It is encoded by the TAC1 gene and plays a pivotal role in the transmission of pain signals (nociception) and the mediation of neurogenic inflammation [2]. Upon release from C-fiber terminals, Substance P binds to the Neurokinin 1 (NK1) receptor, triggering various physiological responses including vasodilation, plasma extravasation, and immune cell activation [3]. Pharmacological modulation of the Substance P synthesis and release pathway is a key strategy in managing conditions such as chronic pain, pruritus, and chemotherapy-induced nausea and vomiting [4]. Drugs like capsaicin act by initially stimulating and then depleting Substance P stores, while NK1 receptor antagonists block the downstream signaling essential for its biological effects [5].

Other names

Neurokinin PTachykinin 1TAC1Preprotachykinin APPT-A

Therapeutic modulation involves the depletion of neuropeptide stores in sensory neurons, inhibition of calcium-dependent exocytosis, or competitive antagonism of the Neurokinin 1 receptor to block downstream signaling cascades [1, 5].