We studied the effects of substances P administration on tracheal mucus viscoelasticity, water content, clearability and secretion rate. Six neutered adult male ferrets (weight 1.1-1.5 kg) were studied, on four occasions each. They were anaesthetized with ketamine and xylazine, and intubated shallowly. Control mucus (pre- and post-Ringer instillation) was compared with the mucus obtained follow...

Most airway mucus is produced by submucosal glands in response to neural signals. Gland mucus traps microbes, inhibits their replication, and clears them from the airways. In cystic fibrosis mucus clearance is compromised, allowing pathogens to persist in static mucus. These trigger an influx of inflammatory cells, but optimal effectiveness of inflammation, and especially its resolution, also r...

BACKGROUND Ascending infection from the colonized vagina to the normally sterile intrauterine cavity is a well-documented cause of preterm birth. The primary physical barrier to microbial ascension is the cervical canal, which is filled with a dense and protective mucus plug. Despite its central role in separating the vaginal from the intrauterine tract, the barrier properties of cervical mucus...

Bacteriophages (phages) defend mucosal surfaces against bacterial infections. However, their complex interactions with their bacterial hosts and with the mucus-covered epithelium remain mostly unexplored. Our previous work demonstrated that T4 phage with Hoc proteins exposed on their capsid adhered to mucin glycoproteins and protected mucus-producing tissue culture cells in vitro. On this basis...

Allen, Adrian, and Gunnar Flemström. Gastroduodenal mucus bicarbonate barrier: protection against acid and pepsin. Am J Physiol Cell Physiol 288: C1–C19, 2005; doi:10.1152/ajpcell.00102.2004.—Secretion of bicarbonate into the adherent layer of mucus gel creates a pH gradient with a near-neutral pH at the epithelial surfaces in stomach and duodenum, providing the first line of mucosal protection...

The airway epithelial surface liquid is generally considered to be composed of two layers, a periciliary layer and a continuous thick mucus layer moving in bulk. This view may not be appropriate for all areas of the lung. Our hypothesis, that mucus may form a discontinuous layer with dynamic attachments to the surface, is investigated using a culture system. We used live-cell confocal microscop...

Colonic mucus is a key biological hydrogel that protects the gut from infection and physical damage and mediates host-microbe interactions and drug delivery. However, little is known about how its structure is influenced by materials it comes into contact with regularly. For example, the gut abounds in polymers such as dietary fibers or administered therapeutics, yet whether such polymers inter...

Leptin has been suggested to be involved in tissue injury and/or mucosal defence mechanisms. Here, we studied the effects of leptin on colonic mucus secretion and rat mucin 2 (rMuc2) expression. Wistar rats and ob/ob mice were used. Secretion of mucus was followed in vivo in the rat perfused colon model. Mucus secretion was quantified by ELISA, and rMuc2 mRNA levels were quantified by real-time...

The final boundary between digested food and the cells that take up nutrients in the small intestine is a protective layer of mucus. In this work, the microstructural organization and permeability of the intestinal mucus have been determined under conditions simulating those of infant and adult human small intestines. As a model, we used the mucus from the proximal (jejunal) small intestines of...

BACKGROUND The secreted proteins from goblet cells compose the intestinal mucus. The aims of this study were to determine how they exist in two intestinal mucus layers. METHODOLOGY/PRINCIPAL FINDINGS The intestinal mucosa was fixed with Carnoy solution and immunostained. Mucus from the loose layer, the firm layer was gently suctioned or scraped, respectively, lysed in SDS sample buffer with o...