Functional Studies with Substance P Analogues: Effects of N‐Terminal, C‐Terminal, and C‐Terminus‐Extended Analogues of Substance P on Nicotine‐Induced Secretion and Desensitization in Cultured Bovine Adrenal Chromaffin Cells

Abstract

Substance P (SP) and SP analogues, including C-terminal, N-terminal, and C-terminus-extended analogues, have been investigated for their ability to modulate nicotine-induced secretion from bovine adrenal chromaffin cells in culture. Secretion was monitored by measuring the release of endogenous catecholamines by electrochemical detection following separation on HPLC and the release of endogenous ATP with an on-line luciferin-luciferase bioluminescence technique. SP is known to have the following two effects on nicotine-induced secretion of catecholamines (see Livett and Zhou, 1991): inhibition of the nicotinic response and protection against nicotinic desensitization. Secretion induced by M nicotine was inhibited 70-80% by SP, SP-methyl ester, and the C-terminusextended analogue SP-Tyr"-NH,, 65% by (Ala3)SP-NH,, 45% by the C-terminal analogue SP(4-1 l), and 20 and 5% by the N-terminal analogues SP(1-7) and SP(1-5), respectively, when these peptides were present at 3 X

Two Chromogranin A-Derived Peptides Induce Calcium Entry in Human Neutrophils by Calmodulin-Regulated Calcium Independent Phospholipase A2

“…In addition to CAT, substance P is another neuro-immunomodulator that may inhibit nicotinic cholinergic-stimulated catecholamine release, but displays a lower potency [70]. PACAP displays numerous functions in cells of neuronal and non neuronal origin and functional VIP/PACAP receptors have been demonstrated on PMNs, mediating Ca 2+ - dependent pro-inflammatory activities through the activation of multiple regulatory pathways [71].…”

The role of Substance P in the defense line of the respiratory tract and neurological manifestations post COVID-19 infection

“…For a more in-depth investigation of postsynaptic attack, studies were performed on isolated chromaffin cells with Bruce Livett (Melbourne) ( 14 ) to understand the modulation of synaptic transmission in these cells. This showed that SP has two effects.…”