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PubMed1988

Sampling technique and rheology of human tracheobronchial mucus.

The aims of this work were: (1) to establish a technique for the sampling of human tracheobronchial mucus not contaminated by saliva or topical anesthesia, and (2) to measure its viscoelastic properties. After local anesthesia of the hypopharynx by topical application of 4% xylocaine, a double-sleeve microbiology specimen brush was introduced into a flexible bronchoscope placed in the trachea. The brush was left in direct contact with the bronchial mucosa for 20 to 30 s to allow mucus to collect on it. The mucus sample was then scraped from the brush and immediately covered with paraffin oil. Its viscoelastic properties were determined by the magnetic microrheometer technique. Excluding the time to anesthetize, the whole procedure took less than 1 min (thus minimizing the effect of cough) and resulted in sufficient mucus for rheologic analysis in approximately 90% of trials, i.e., 2.1 +/- 1.5 (SD) mg. Mucus specimens were collected from 20 fasting healthy nonsmoking subjects; 17 of them returned for a second collection several days later. Values for mucus mechanical impedance (vector sum of elasticity and viscosity) at 1 rad/s were: Control 1, 141 +/- 41 (SE); Control 2, 155 +/- 58 dyn/cm2. There was a large variation in mucus viscoelasticity, both between subjects (CV, 130%) and within the same subject (CV, 55%) on different days. In 7 subjects, mucus samples were collected 15 min after intravenous injection of 0.6 mg atropine. Viscoelasticity in these samples was 708 +/- 147 dyn/cm2, a value significantly different from Control 1 (p less than 0.05) and Control 2 (p less than 0.05) values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2001

The Amount of MUC5B mucin in cervical mucus peaks at midcycle.

The physical character and amount of mucus secreted by the endocervix changes dramatically during the menstrual cycle to facilitate sperm migration at the time of midcycle ovulation. Mucins are highly glycosylated, high-molecular-weight proteins, which are the major structural components of the protective mucus gel covering all wet-surfaced epithelia, including that of the endocervix. We have previously demonstrated that the endocervical epithelium expresses messenger RNA (mRNA) of three of the large gel-forming mucins, designated MUC5AC, MUC5B, and MUC6, with mRNA of MUC5B predominating. Because mucin protein levels may be regulated posttranscriptionally, measurement of MUC5B protein levels with cycle are needed for correlation to mRNA levels. Measurement of specific mucin gene products within mucus secretions has been limited by availability of specific, well-characterized antibodies and by volume requirements of the isolation protocols for mucins, which include CsCl density centrifugation and fraction isolation. To measure MUC5B protein within the cervical mucus through the hormone cycle, we developed a polyclonal antibody specific to the mucin. The antibody, designated no. 799, is to a synthetic peptide mimicking a 19-amino-acid segment of an intercysteine-rich region within the D4 domain in the 3' region of the MUC5B protein. It recognizes native as well as denatured MUC5B on immunoblot, is preadsorbable with its peptide, and binds to apical secretory vesicles of epithelia expressing MUC5B. We used the MUC5B antibody along with a cervical mucin standard cervical mucin isolate in enzyme-linked immunosorbent assay to determine the relative amount of MUC5B mucin in samples of human cervical mucus taken through the menstrual cycle. We demonstrate a peak of MUC5B mucin in human cervical mucus collected at midcycle, compared with mucus from early or late in the cycle. This peak in MUC5B content coincides with the change in mucus character that occurs at midcycle, suggesting that this large mucin species may be important to sperm transit to the uterus.

Amino Acid Sequence↗
PubMed1999

Barrier function of gastric mucus.

A viscoelastic mucus gel layer covers the gastric mucosa in a continuous sheet. The functions of the mucus gel have been one of the least studied aspects of gastric barrier function. Although the role of gastric mucus in providing physical protection against ingested particles, and preventing contact between digestive enzymes such as pepsin and the underlying mucosa is generally accepted, the barrier role function of gastric mucus with regard to luminal acid is still conjectural. The modest proton diffusion barrier that mucus provides is negligible in relation to the overall barrier properties of the gastric mucosa; nevertheless, stabilization of unstirred layers and damping of rapid shifts in luminal pH are potentially important functions. Associative studies have suggested a possible role of a hydrophobic barrier in strengthening the barrier functions of mucus. One of the most actively investigated areas of mucus function in recent times has been the mechanism by which secreted acid traverses the gel. Although compelling and complementary data obtained in vivo and in vitro have been consistent with secretion of acid under pressure, creating temporary viscous fingers through the gel, recent evidence obtained with in vivo confocal microscopy suggests that secreted acid diffuses through the gel. Since Helicobacter pylori exists solely in the juxtamucosal portion of the gastric mucus gel, detailed knowledge concerning the pH microenvironment in which the organism thrives is important in understanding the pathophysiology of peptic ulcer disease and related conditions.

Animals↗
PubMed2003

Coughing, mucus accumulation, airway obstruction, and airway inflammation in control horses and horses affected with recurrent airway obstruction.

OBJECTIVE: To investigate relationships between cough frequency and mucus accumulation, airway obstruction, and airway inflammation and to determine effects of dexamethasone on coughing and mucus score. ANIMALS: 13 horses with recurrent airway obstruction (RAO) and 6 control horses. PROCEDURE: 6 RAO-affected and 6 control horses were stabled for 3 days. Coughing was counted for 4 hours before and on each day horses were stabled. Before and on day 3 of stabling, tracheal mucus accumulation was scored, airway obstruction was assessed via maximal change in pleural pressure (deltaPpl(max)), and airway inflammation was evaluated by use of cytologic examination of bronchoalveolar lavage fluid (BALF). Effects of dexamethasone (0.1 mg/kg, IV, q 24 h for 7 days) were determined in 12 RAO-affected horses. RESULTS: To assess frequency, coughing had to be counted for 1 hour. In RAO-affected horses, stabling was associated with increases in cough frequency, mucus score, and deltaPpl(max). Control horses coughed transiently when first stabled. In RAO-affected horses, coughing was correlated with deltaPpl(max), mucus score, and airway inflammation and was a sensitive and specific indicator of deltaPpl(max) > 6 cm H2O, mucus score > 1.0, and > 100 neutrophils/microL and > 20% neutrophils in BALF Dexamethasone reduced cough frequency, mucus score, and deltaPpl(max), but BALF neutrophil count remained increased. CONCLUSIONS AND CLINICAL RELEVANCE: Because of its sporadic nature, coughing cannot be assessed accurately by counting during brief periods. In RAO-affected horses, coughing is an indicator of airway inflammation and obstruction. Corticosteroid treatment reduces cough frequency concurrently with reductions in deltaPpl(max) and mucus accumulation in RAO-affected horses.

Airway Obstruction↗
PubMed1987

Rheological properties controlling mucociliary frequency and respiratory mucus transport.

Respiratory mucus and mucosa possess highly hydrophilic structures which are difficult to preserve using standard fixative methods. The close interaction between cilia and mucus can be observed after instantaneously interrupting the ciliary movement using ultra rapid and cryosubstitution fixation methods. Mucus possess several rheological properties such as pseudoplasticity, elastothixotropy, spinability and adhesiveness. Rheological properties of mucus may control, per se, the ciliary beating frequency. By measuring the mucociliary frequency on the excised mucus-depleted frog palate of native mucus and xanthan gum using a simulant of mucus, we observed that beyond an optimal value of viscosity (close to 12 Pa.s) the mucociliary frequency and transport rate decrease in parallel. Other rheological factors such as adhesion and spinability of mucus can also be implicated in the regulation of the mucociliary transport rate.

Animals↗
PubMed1989

The role of mucus gel viscosity, spinnability, and adhesive properties in clearance by simulated cough.

We investigated the role of the viscoelastic and adhesive properties of mucus gel simulants on the clearance of mucus by simulated cough. Mucus-like gels with widely varying viscoelastic properties were prepared from polysaccharides crosslinked with sodium borate. Cough was simulated by opening a solenoid valve connecting a model trachea to a pressurized tank. The clearance of gels lining the model trachea was quantified by observing marker particle transport. Viscosity elastic modulus, relaxation time and yield stress were measured with a steady-shear viscoelastometer. Spinnability (thread formation) was determined with a filancemeter. Adhesivity (surface tension) was measured by the platinum ring technique. The viscoelastic and adhesive properties of the mucus gel simulants spanned the ranges observed for bronchial secretions from patients with COPD. The relationship between simulated cough clearance and the viscoelastic and adhesive properties of the gels was analyzed by stepwise linear regression of the non-zero data matrix. The major independent variable relating to clearance was viscosity. Secondary, but highly significant dependences, were also found for spinnability and adhesivity. Elastic modulus, relaxation time and yield stress had no independent effect on cough clearance over the investigated range. The results indicate that, in the absence of airway surface liquid, cough-type clearance relates primarily with mucus gel viscosity. For a given viscosity, clearance is also impaired by spinnability, i.e. the capacity of the mucus to form threads. At constant viscosity and spinnability, clearance is further impaired by an increase in the adhesivity of the mucus. The negative dependence of each of these physical factors can be rationalized in terms of their inhibitory effect on wave formation in the mucus lining layer during high velocity airflow interaction.

Adhesiveness↗
PubMed1989

Comparative rheological profile of rat gastric and duodenal gel mucus.

Methods for measuring the adhesiveness, plasticity, viscoelasticity and spinnability of mucus microsamples have been developed. The rheological properties of the rat gastric and duodenal gel mucus have been analyzed and compared. Using a controlled stress rheometer (Carri-Med), flow and creep experiments showed that gastroduodenal mucus exhibits a typically non-newtonian, pseudoplastic and viscoelastic behaviour. The apparent viscosity (7,800 +/- 11,000 Pa.s) and yield stress (24.9 +/- 8.5 Pa) of gastric mucus were significantly higher than the duodenal mucus viscosity (39 +/- 160 Pa.s) and yield stress (12.9 +/- 2 Pa). Spinnability of gastric mucus, measured with a Filancemeter (SEFAM), was significantly lower (4.9 +/- 2.5 mm) in comparison to duodenal mucus (6.9 +/- 1.5 mm). Adhesive properties of gastric mucosa (analyzed with the platinum ring method) were not significantly different in comparison to duodenal mucus (99.9 +/- 31.5 mN/m and 92.8 +/- 11.2 mN/m, respectively).

Adhesiveness↗
PubMed1990

[Inhibitory effect of nasal mucus on the absorption of drugs through respiratory epithelium].

The absorption of Dibekacin (DKB) through rabbit's tracheal mucosa with and without nasal mucus were examined in vitro. The modified double chamber method was used for the purpose of this study. DKB solution (20 mg/ml) and Hanks' balanced salt solution were put into the donor compartment (DC) and the receiver compartment (RC), respectively. A plate with a hole and the tracheal mucosa were inserted between the compartments in the order of DC, dialytic membrane, the plate, the rabbit tracheal mucosa and RC. The hole of the plate was filled with nasal mucus or Hanks' solution. The latter was used as the control. The chamber was incubated in a humidified atmosphere of 5% CO2 in air for 3 hours at 37 degrees C. The absorption rate (AR) was obtained by dividing the concentration of DKB in RC by that in DC. The nasal mucus from patients with chronic sinusitis significantly decreased the AR of DKB compared with that in the control (P less than 0.05). The AR significantly decreased with increments in the thickness of nasal mucus by chronic sinusitis. This decreased AR was improved by the addition of N-Acetyl-L-cysteine (NAC) to DKB solution in DC. NAC can cleave disulfied bonds of mucus glycoprotein and this results in the decrease of viscoelasticity of nasal mucus. The results indicate that nasal mucus by chronic sinusitis intercept the absorption of drugs through respiratory epithelium in vitro. One of the mechanisms of the intercepter may be due to the high molecular-reticular structure of nasal mucus.

Absorption↗
PubMed2003

[Rheology of human cervical mucus--with special reference to measurement of viscoelasticity using various rheometers].

Cervical mucus is egg white-like mucus that increases in the female cervical canal and external os of the uterus at ovulatory phase. Spermatozoa climb up through this mucus to the uterine tube, where they meet an oocyte causing fertilization. If this cervical mucus has quality or quantity problems, spermatozoa are unable to ascend. Then, so-called infertility due to cervical hostility would occur(5% in general). One day before ovulation, because there is the highest amount of cervical mucus, the greatest degree of Spinnbarkeit and the lowest degree of viscoelasticity, spermatozoa are able to penetrate it in the easiest way according to the paper by Moghissi KS, et al. In another paper by Wolf DP, et al., the strict measuring of the cervical mucus Spinnbarkeit and viscoelasticity using magnetic microrheometer was explained. On the other hand, we were able to calculate in an easier way the cervical mucus viscoelasticity by the NEVA (new equipment for viscosity assessment) meter (Ishikawa Iron Works Corporation, Kitakyushu). We review the rheology of human cervical mucus including our data with the NEVA meter.

Cervix Mucus↗
PubMed1999

Interactions of EGF and ornithine decarboxylase activity in the regulation of gastric mucus synthesis in cigarette smoke exposed rats.

Cigarette smoking has been shown to aggravate ulceration and delay ulcer healing. Smokers had a lower level of mucus in their stomachs. In the present study, we examined whether cigarette smoke or its extract reduced mucus production through the suppression of epidermal growth factor (EGF) associated with the reduction of polyamine biosynthesis both in vivo and in vitro. Ornithine decarboxylase (ODC) activities and mucus synthesis were determined in rat gastric mucosa and in human MKN-28 cells. Incubation of MKN-28 cells with EGF (0.01-1.00 ng/mL) significantly increased mucus synthesis in vitro, which was accompanied by an increase of ODC activity. Removal of salivary glands decreased the circulated EGF level and induced a significant reduction of mucus-secreting layer thickness in the gastric mucosa. Cigarette smoke or its extract markedly decreased mucus synthesis in vivo and in vitro, both of which could be completely reversed by intravenous administration of EGF (20 microg/kg) in rats or co-incubation with EGF (1 and 2 ng/mL) in MKN-28 cells. However, ODC activities, which were suppressed by cigarette smoke or its extract, were unaffected by intravenous administration of EGF in rats, or only partially reversed by co-incubation with EGF in MKN-28 cells. These findings indicate that both EGF and ODC activity represent two different entities in the modulation of cigarette smoking on gastric mucus synthesis. The action of EGF on mucus synthesis may only be partially if not dependent on ODC activity in the stomach.

Adenocarcinoma↗
PubMed2001

Mucus fishing syndrome: case report and new treatment option.

BACKGROUND: Mucus fishing syndrome (MFS) is a cascading cyclic condition characterized by continuous extraction of mucous strands from the eye. It is usually initiated by ocular irritation. In response to irritation, ocular surface cells produce excess mucus. A "snow balling" cycle begins when the patient extracts ("fishes") excess mucus from the ocular surface, thereby causing further irritation and a more-profound mucous discharge. To date, treatment includes eliminating the initiating element and educating the patient not to touch the eye when extracting the excess mucus, CASE REPORT: Presented is a case of mucus fishing syndrome initiated by dry eye. The patient's diagnosis, MFS, was identified by persistent mucous discharge, his admittance and demonstration of digitally extracting mucus from the ocular surface, and a characteristic rose bengal staining pattern. The conventional treatment initiated by using artificial tears for the dry eye condition and educating the patient not to touch the ocular surface did not provide relief from the excess mucous discharge. Therefore, a new approach to treatment was pursued. In order to break the cycle, a mucolytic agent and an antihistamine-mast cell stabilizer were prescribed, until the ocular surface healed. After treatment, the patient reported alleviation of symptoms and demonstrated improvement in ocular surface integrity by a profound reduction in rose bengal staining. CONCLUSION: Mucus fishing syndrome is challenging to resolve with conventional treatment because it requires a certain level of psychological tolerance and perseverance from the patient. By eliminating the present mucus and diminishing mucous production pharmacologically, the practitioner is able to remove the stimulus for digital extraction and thus accelerate ocular surface healing. We present a proposed new treatment option for patients who are refractory to conventional treatments.

Cystine↗
PubMed2001

HCO3- transport in relation to mucus secretion from submucosal glands.

The role of HCO(3)(-) transport in relation to fluid secretion by submucosal glands is being studied in sheep, pigs, cats and humans. Optical methods have been developed to measure secretion rates of mucus volume from single glands with sufficient temporal resolution to detect differences in minute-by-minute secretion rates among glands. The ionic composition and viscoelastic properties of the uncontaminated gland mucus are measured with a combination of ratiometric fluorescent indicators, ion-selective microelectrodes, FRAP, and a miniaturized, magnetic force viscometer. Sheep glands secreted basally at low rates, showed small, transient responses to alpha- and beta-adrenergic agonists, and large responses to a cholinergic agonist, carbachol. Peak rates and temporal patterns of responses to carbachol differed markedly among glands. To assess the contribution of HCO(3)(-) transport to gland secretion, we either inhibited Na(+)/K(+)/2Cl(-) cotransporter (NKCC) with bumetanide or replaced HCO(3)(-) with HEPES and gassed with O(2). Bumetanide caused a small, non-significant inhibition of basal secretion, but removal of HCO(3)(-)/CO(2) significantly reduced basal secretion almost by half. Both bumetanide and removal of HCO(3)(-)/CO(2) reduced carbachol-stimulated secretion significantly, with HCO(3)(-) removal having the larger effect: a reduction to 33% of control (P<0.01). The remaining secretory response to carbachol was nearly eliminated by bumetanide. Sheep mucus pH measured with ion selective electrodes was about 0.4 log more acidic than the bath. In humans, we observed the same pattern of responses to agonists and antagonists as in sheep, and observed a mucus pH of 7.0 using 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF). We hypothesize that HCO(3)(-) transport is important in the formation of mucus secretion, but that most HCO(3)(-) is scavenged before the final mucus appears at the duct opening. Cystic fibrosis transmembrane conductance regulator's (CFTR) best understood function is as an anion channel, but increasing attention has been given to its role in HCO(3)(-) transport. By analogy with organ-specific CFTR effects on Cl(-) transport, it seems likely that the relative importance of CFTR in HCO(3)(-) transport will also vary across organs. Because lung disease is by far the greatest cause of mortality among people with cystic fibrosis, it is important to determine how loss of CFTR function causes lung disease. We are testing the hypothesis that loss of CFTR alters serous cell secretion in the lungs, and the corollary that such loss contributes to cystic fibrosis (CF) lung disease. CFTR is highly expressed in serous cells of submucosal glands and the Calu-3 serous cell model secretes HCO(3)(-). Human gland serous cells grown in culture and tested for fluid secretion under open circuit conditions showed reduced fluid secretion to all mediators. However, submucosal glands are complex organs containing at least 4 distinct regions and at least that many cell types, making it difficult to predict the consequences on whole-organ function from experiments with individual cell types. Therefore, we have resurrected long-neglected methods for studying whole-gland function, and have attempted to improve them in a variety of ways. We are refining these methods and increasing our understanding of gland function by studying tracheal glands from sheep, pigs and cats. As human tissues become available, they are studied with the best methods presently available. The key questions now being asked are: Is mucus secretion from submucosal glands altered in cystic fibrosis? If so, how is it altered and how does it contribute to CF lung disease? Answering the last question will require an understanding of how glands interact with other regions of the lung. In the context of this meeting, we present preliminary data on the role of HCO(3)(-) in gland mucus secretion.

Animals↗
PubMed2003

Interaction of laminar airflow with viscoelastic airway mucus.

Basic wave interaction mechanism between the laminar airflow and viscoelastic layer in a rigid tube is investigated numerically. The purpose is to explore the effect of mucus viscoelasticity on the stability of the coupled airflow-mucus system in pulmonary airways under clinical conditions where the serous layer is absent. The results indicate that the onset flow speed, for the initiation of unstable surface waves, is very sensitive to mucus viscosity and it may be as high as 35 times the elastic case for a very viscous mucus with the same elasticity. While the onset speed and wavelength increases, wave speed decreases with increasing mucus viscosity, reducing from about 40% of the flow speed for elastic mucus to less than 1% for a very viscous mucus. Also, a case study for a patient with chronic bronchitis shows that large amplitude waves may form on the mucus surface during forced expiration.

Air↗
PubMed1992

Effect of rebamipide on mucus secretion by endogenous prostaglandin-independent mechanism in rat gastric mucosa.

The effect of rebamipide (2-(4-chlorobenzoylamino)-3-[2 (1H)-quinolinon-4-yl]-propionic acid, OPC-12759, CAS 11911-87-6), an anti-ulcer agent developed to enhance defensive factors in the gastric mucosa, on gastric mucus secretion was studied by a newly developed biochemical method to measure the gastric mucus glycoprotein content in rats. 1 h after intraperitoneal administration, rebamipide did not produce a significant change in the intramucosal mucus contents (surface mucosal layer and deep mucosal layers of corpus and antral regions) but significantly increased the content of soluble mucus, which recovered from the gastric contents, to about 160% of the control value. Since rebamipide has been shown to increase the biosynthesis of prostaglandins, indometacin was administered to the rats prior to rebamipide administration to examine whether the increase in prostaglandin biosynthesis contributes to the rebamipide-induced increase in gastric mucus secretion. The increase in the soluble mucus was not altered by the pretreatment with indometacin, thus indicating that rebamipide per se has a potential to increase the gastric mucus secretion by a mechanism that is not mediated by the endogenous prostaglandins. The effect of rebamipide on the gastric mucus secretion might contribute to heal and to prevent the recurrence of peptic ulcer diseases as well as to maintain the homeostasis of the gastric mucosa.

Alanine↗
PubMed2004

[Mucus physicochemical properties in children with ulcerative colitis].

The aim of the study was to estimate colonic mucus physicochemical state in children with ulcerative colitis. Investigations were performed in 36 children, aged 10-17 years, allotted into three groups dependently on the severity of the disease. The severity of the disease was estimated basing on Truelove-Witts criteria. Mucus analysis was performed with polyacrylamide gel electrophoresis (SDS-PAGE), electron paramagnetic resonance (EPR) and spectrophotometric method. Mucus fraction dissolved in normal saline was subject of investigations. Protein content was determined in this fraction with Lowry's method. The obtained results demonstrated different mucus solubility dependent on the severity of the disease. Mucus protein concentration increased whereas mucus viscosity decreased with the severity of the disease. Colonic mucus physicochemical properties change dependently on the disease severity. Determination of soluble protein fraction in mucus may be a useful marker in the estimation of the disease severity.

Adolescent↗
PubMed2006

[Ovulatory mucus and its pH, arborization and spermagglutination antibodies in women with fertility disorders].

OBJECTIVE: We studied pH of ovulatory mucus, sperm penetration through capillary filled with ovulatory mucus in one hour and presence of local spermagglutinating antibodies. METHODS: We measured pH, arborization and Kremer test in ovulatory mucus in 127 women with fertility disorder. Indirect mixed antiimunoglobulin reaction test (i-MAR-test for IgG, IgA, IgM and IgE) was used for detection of spermagglutinating antibodies. RESULTS: pH 7.4-9.6 (physiological limit) was found in 94/127 women (74%), pH < 7.4 in 33 women (26%). 60% of 94 patients with physiological pH had Kremer's test above 2cm/hour (normal sperm penetration in ovulatory mucus), in 40% of them reduction of sperm penetration (< 2cm/hour, swelling, shaking, cytotoxicity) was seen. Sperm antibodies in ovulatory mucus in 24% patients with pH < 7.4 and 22% patients with physiological pH were studied. In 111 patients with regular menstrual cycle a classical arborization was found in 81%, in 14% was not proved. In 16 patients with irregular menstrual cycle classical arborization was observed in 11 of them. Local sperm antibodies were detected only in 13% of the total count of patients, it means in 17 patients. Their ovulatory mucus showed classical arborization. 30 healthy fertile women created the control group, only one secretion had pathological findings in all studied parameters owing to latent mycotic infection. SUMMARY: Pathological pH of ovulatory mucus, hormonal dysbalance, and presence of local spermagglutinating antibodies evidently influence penetration of sperm cells through cervix uteri. Otherwise pathological microbial vaginal environment can start a cross reaction with the surface microbes and sperm epitopes. One sign of ovulation, arborization of cervical ovulatory mucus, is not connected directly with the presence of local sperm antibodies, but insufficient estrogen influence is a sign of the reduced immunosuppression in cervix area.

Antibodies↗
PubMed1990

[Airway hyperresponsiveness and mucus secretion].

A large amount of mucus and mucoid impaction are observed in the autopsied lungs of bronchial asthmatics. It is possible that mucus hypersecretion and accumulation of intrabronchial mucus result in bronchial obstruction and structural bronchial hyperresponsiveness. Bronchial gland plays a main role in human airway secretion. We describe here some results using isolated gland preparation which enable us to examine airway mucus secretion in a well-defined condition. Chemical mediators released from mast cells augment the secretory responses induced by cholinergic nerve stimulation through accelerated acetylcholine release in the nerve terminals. PAF produces an increase in mucus glycoprotein secretion in the presence of platelets mainly through the thromboxane release from platelets. Substance P which is released by an axon reflex in response to various stimuli and inflammations in the airways, also produced an increase in mucus secretion. Epithelial cells release an inhibitory factor to mucus glycoprotein secretion from bronchial glands. Epithelial cell damages due to inflammation in the airways may induced a reduction of the inhibitory factor release in bronchial asthmatics, resulting in mucus hypersecretion.

Asthma↗
PubMed1991

Enhancement of the physicochemical qualities of gastric mucus by sofalcone.

The effect of prolonged administration of an antiulcer drug, sofalcone, on the physicochemical properties of gastric mucus was investigated. The experiments were conducted with groups of rats receiving twice daily for three consecutive days a dose of 100 mg/kg sofalcone, while the control group received daily doses of vehicle. The rats were sacrificed 16 h after the last dose and gastric mucosa subjected to physicochemical measurements. The results revealed that sofalcone evoked a 23% increase in mucus gel dimension, while sulfo- and sialomucins content of the gel increased by 54 and 25%, respectively. These changes were accompanied by a 16% increase in mucus H+ retardation capacity, 2-fold increase in viscosity, and a 39% increase in the gel hydrophobicity. The mucus elaborated in the presence of sofalcone contained 67% more covalently bound fatty acids, exhibited 10% lower content of protein, 30% higher content of carbohydrate, and 18% higher content of lipids. The mucus of the sofalcone group also showed an increase in the proportion of the high molecular weight mucus glycoprotein form, which in the control group accounted for about 30% of gel mucin, while its content in mucus gel of animals receiving sofalcone reached the value of 50%. The results indicate that sofalcone enhances the protective qualities of mucus component of gastric mucosal barrier.

Alcian Blue↗