Quantitative assessment of villous motility

Abstract

A videomicroscopic method was used to quantitatively analyze villous motility in the dog small intestine. The frequency and duration of villous contractions (retractions) were measured in the duodenum, midjejunum, and distal ileum under controlled conditions. A pronounced gradient of villous motility was evident along the bowel. The duodenum exhibited the highest frequency (7.3 +/- 0.1/min) and longest duration (2.6 +/- 0.1 s) of contraction; the jejunum exhibited an intermediate frequency and duration of contraction (4.0 +/- 0.1/min, 2.1 +/- 0.1 s), and the lowest values were measured in the ileum (2.0 +/- 0.1/min and 1.8 +/- 0.1 s). In contrast to the retraction movements, the frequency of pendular villous movements (whipping, swaying movements without shortening) was highest in the jejunum and lowest in the duodenum. The frequency and duration of villous contractions (retractions) remained relatively constant over a 2-h observation period. Reducing mucosal surface temperature from 38 to 30 degrees C caused the frequency of contraction to fall by 33% and the duration to increase by 106%. Varying the suffusate pH within the physiological range of 5.0-7.4 produced no significant effects on jejunal villous motility. Suffusion with glucose (140 and 280 mM) failed to alter villous motility. However, amino acid (15 and 30 mM) and fatty acid (10 mM) solutions significantly increased contraction frequency by 30-50% and 90%, respectively. The videomicroscopic method provides useful quantitative information, which should extend current knowledge regarding the regulation and physiological importance of villous motility.

Intravital imaging of intestinal lacteals unveils lipid drainage through contractility

“…Previous reports only described villus motion as pistonlike retraction and extension, which was speculated to be mediated by smooth muscles that are aligned longitudinally along the lacteal (36,37) to facilitate the initial lymph drainage (34). On the other hand, our study directly visualized the lateral contrac tion of lacteals in concert with adjacent smooth muscles, which showed that lacteals possess unique characteristics as a part of an organspecific lymphatic system.…”

DLL4 promotes continuous adult intestinal lacteal regeneration and dietary fat transport

“…Detailed characterization of adult lacteals revealed that they undergo continuous and slow remodeling (Figure 3). Unlike most other capillary beds, the vessels of small intestinal villi are continuously exposed to high concentrations of lipoprotein particles and other biologically active dietary and microbial products, such as retinoic acid (2) or Toll-like receptor ligands (63); gradients of osmolarity (64); and high mechanical strain due to peristalsis and villus contractions (23). Furthermore, the adult intestine is in a constant state of renewal, as the mouse epithelium is wholly replaced every 5 days (65).…”

About the presence of interstitial cells of Cajal outside the musculature of the gastrointestinal tract

“…1) contacts with axons, with the axial smooth muscle cells, and a partial embracement of capillaries and the terminal arteriole. Citing studies by Womack [35,36], Thuneberg [6] suggested that this network of myofibroblasts may well provide stretch sensitive pacemaking activity to the muscle cells of the villi and may be proven to fall within the classification of ICC. Interestingly, the intravillous myofibroblasts, similar to the ICC, are NK1r-positive and are in close contact to each other and nerve fibers [37].…”