Tachykinins in the gut. Part I. Expression, release and motor function

Area of Science:

• Gastroenterology
• Neuroscience
• Pharmacology

Background:

• Substance P and neurokinin A, derived from the preprotachykinin-A gene, are peptides found in mammalian gut neural pathways.
• These tachykinins interact with NK1, NK2, and NK3 receptors, influencing nerve and muscle activity.

Purpose of the Study:

• To review the role of tachykinins in regulating gastrointestinal motor activity.
• To explore the potential of targeting tachykinin systems for treating gastrointestinal dysmotility.

Main Methods:

• Review of existing scientific literature on tachykinins in the mammalian gut.
• Analysis of the mechanisms by which tachykinins affect gastrointestinal motility.
• Synopsis of data on the physiological and pathological roles of tachykinins.

Main Results:

• Tachykinins primarily exert an excitatory effect on gastrointestinal motor activity across all gut regions and layers.
• This excitation involves direct muscle activation (NK1/NK2) and stimulation of enteric motor pathways (NK3/NK1).
• Tachykinins can also inhibit motor activity by modulating neuronal pathways.

Conclusions:

• Endogenous substance P and neurokinin A are integral to the physiological control of gastrointestinal motility, interacting with other neurotransmitters.
• Disruptions in tachykinin regulation are implicated in gastrointestinal dysmotility linked to infection, inflammation, stress, and pain.
• Tachykinin agonists and antagonists represent potential therapeutic agents for gastrointestinal motor disorders involving the tachykinin system.