Peristalttisin

Peristalttisin is a hypothetical peptide hormone described as a regulator of gastrointestinal peristalsis. In theoretical models, it functions as a signaling molecule that enhances coordinated smooth muscle contractions along the intestine by increasing intracellular calcium in smooth muscle cells and modulating enteric neural circuits.

Biogenesis and structure: It is posited to be a small secreted peptide, approximately 25–30 amino acids, stabilized by one disulfide bond. It would be produced as a prepropeptide in enteric neurons and enteroendocrine cells, processed into an active peptide by prohormone convertases, and stored in secretory granules before release in response to luminal stimuli.

Receptor and mechanism: Peristalttisin is proposed to act by binding to a G protein–coupled receptor, PST1, on smooth muscle cells and enteric neurons. Activation would trigger phospholipase C, generate IP3 and DAG, cause calcium mobilization, and promote rhythmic contractions characteristic of peristalsis. It is also suggested to modulate neural networks that coordinate circular and longitudinal muscle activity.

Physiological relevance and research status: In this hypothetical framework, peristalttisin contributes to the initiation and modulation of migrating motor complexes and postprandial motility. Computational simulations and in vitro tissue preparations have explored its potential effects, but there is no established evidence in living humans. Consequently, clinical applications remain speculative, with research focusing on possible therapies for hypomotility disorders and ileus, subject to safety considerations such as off-target receptor activation.

Etymology and naming: The name blends peristalsis with the common peptide suffix -sin, reflecting its proposed role in coordinating intestinal movement.