Related Experiment Video
Updated: Sep 10, 2026

A Modified Vessel-Sparing Microsurgical Vasoepididymostomy
Published on: June 8, 2022
Flow-driven lumen remodeling and valve opening in the vas deferens
Nicole Ng Shu Ying1, Qin Ying Lim1, Gen Yamada2
1Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.
Abstract:
Biological ducts must transport fluids while preserving structural integrity, yet how mechano-signaling coordinates wall deformation with luminal flow in vivo remains unclear. Here, we combine intravital two-photon excitation microscopy, light-sheet imaging, and Förster resonance energy transfer-based kinase biosensors to resolve ejaculation-like events in the mouse vas deferens. Acute phenylephrine stimulation elicits a sequence of luminal dynamics: an initial retrograde pressure-redistribution wave followed by a ballistic antegrade flow that propels dense sperm suspensions from the proximal to the distal duct. This contraction-driven flow opens a normally collapsed, wrinkled distal segment, driving progressive lumen expansion and unfolding of epithelial wrinkles. We show that the vas deferens actively modulates luminal geometry in response to these flow dynamics: ROCK activity in smooth muscle is required for global contraction and cAMP-associated signaling modulates this contractile response. By contrast, extracellular signal-regulated kinase activity in circumferential smooth muscle is dispensable for the ductal contraction but essential for active, flow-dependent remodeling of the distal lumen, forming the core of the mechano-signaling module that couples sperm flow to valve opening. These findings establish the vas deferens as an experimentally tractable model of ductal tissue hydraulics and reveal a mechano-signaling framework by which a tubular organ converts transient muscular input into robust, directional luminal transport.
Related Concept Videos
Heart Valves
The AV valves prevent the backflow of blood from the ventricles to the atria during ventricular contraction. These valves function with the assistance of the chordae tendineae and papillary muscles. When the ventricles are relaxed, the chordae tendineae are slack, allowing blood to flow from the atria into the...
Autoregulation of Blood Flow
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation.
Structure of Blood Vessels
Arteries and Arterioles
Vascular Spasm
Mechanism of Angiogenesis

