Biorheology - Volume 24, issue 6

Authors: Silberberg, Alex | Copley, Alfred L.

Article Type: Editorial

DOI: 10.3233/BIR-1987-24601

Citation: Biorheology, vol. 24, no. 6, pp. 535-536, 1987

Authors: Silberberg, Alex

Article Type: Editorial

DOI: 10.3233/BIR-1987-24602

Citation: Biorheology, vol. 24, no. 6, pp. 537-538, 1987

Authors: Verdugo, Pedro

Article Type: Editorial

DOI: 10.3233/BIR-1987-24603

Citation: Biorheology, vol. 24, no. 6, pp. 539-540, 1987

Authors: Nadel, Jay A. | Borson, D. Benjamin

Article Type: Research Article

Abstract: Water and secretions interact in airways to produce the sol and gel layers that allow for entrapment of foreign materials and subsequent clearance by ciliary movement and by cough. Active Cl ion transport produces fluid, and this process is activated by products of mast cells (leukotrienes), eosinophils (major basic protein), and by other inflammatory mediators (prostaglandins, bradykinin). Gland secretions produce the bulk of the volume of secretions. Airway irritation stimulates gland secretion reflexly via vagal muscarinic pathways. Recently, the sensory nerves have been discovered to release substance P and other neuropeptides when the airways are irritated. The stimulatory effects of …neuropeptides on gland secretion (and on other inflammatory sites) are modulated by enkephalinase, a membrane-bound enzyme that cleaves neuropeptides and thereby inactivates them. Up- or down-regulation of enkephalinase is predicted to change the degree of inflammatory response to neuropeptides. Finally, the cell surface of airway epithelial cells have been discovered to secrete large molecular weight glycoconjugates; these secreted products are increased markedly by a series of proteinases produced by inflammatory cells (neutrophils, mast cells) and by bacteria. Their exact physiologic roles are still unknown but they may contribute to the bulk and viscoelastic properties of airway secretions, and they may serve an important role in bacterial, viral and inflammatory cell adhesion. Show more

Keywords: airways secretion, ion transport, inflammation, leukotrienes, prostaglandins, substance P, enkephalinase, neuropeptides, glycoconjugate

DOI: 10.3233/BIR-1987-24604

Citation: Biorheology, vol. 24, no. 6, pp. 541-549, 1987

Authors: Widdicombe, J.H.

Article Type: Research Article

Abstract: Airway epithelia possess transepithelial ion transport processes which may help to regulate the fluid content of airway secretions. Chloride secretion promotes fluid movement from blood to airway lumen. Active absorption of Na favours fluid movement in the opposite direction. The balance between these two processes can be altered by a number of agents which stimulate Cl secretion. The importance of ion transport for normal mucociliary clearance is suggested by the finding that airway epithelia in patients with cystic fibrosis are unable to secrete chloride. This defect may cause the characteristically sticky and tenacious mucous secretions which are the major cause …of death in this disease. Show more

Keywords: mucociliary clearance, fluid transport, chloride secretion

DOI: 10.3233/BIR-1987-24605

Citation: Biorheology, vol. 24, no. 6, pp. 551-555, 1987

Authors: Puchelle, E. | Zahm, J.M. | Quemada, D.

Article Type: Research Article

Abstract: 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. Show more

Keywords: mucus, rheology, quick freezing, cilia, frog palate, beat frequency, mucociliary transport, xanthan gum

DOI: 10.3233/BIR-1987-24606

Citation: Biorheology, vol. 24, no. 6, pp. 557-563, 1987

Authors: Lee, Sum P. | Nicholls, Jane F.

Article Type: Research Article

Abstract: The interposition of a neutral starch gel greatly retarded bulk ionic movement by free flow. A mucus (charged) gel preparation of identical concentration and thickness further retarded ionic diffusion. The findings suggest that the charges in the mucus matrix may exert an ionic exclusion effect (Donnan Exclusion). thus retarding other ionic diffusion. We speculate that a mucus layer may physiologically behave as an ion exchange gel column and modify the traffic of charged ions through it.

Keywords: gastric mucus, pig, ion diffusion, Donnan equilibrium

DOI: 10.3233/BIR-1987-24607

Citation: Biorheology, vol. 24, no. 6, pp. 565-569, 1987

Authors: Deyrup-Olsen, I. | Martin, A.W.

Article Type: Research Article

Abstract: The mucus secreted by the body surface of the terrestrial pulmonate slug, Ariolimax columbianus , is a variable mix of products of the giant mucous and channel cells of the skin. An in vitro sac preparation allows the study of control and products of these two cell types. Mucins in membrane-bound granules are released by the mucous cells on mechanical or electrical stimulation of the skin. The product of the channel cells is a blood ultrafiltrate, modified by reabsorption of Na+ and Cl− ions and transfer into the fluid of K+ and HCO3 − ions (processes …of secretion inhibited by ouabain, amiloride and furosemide; and by other epithelial blocking agents). Rates of secretion can be increased or decreased by gastropod neurotransmitters (acetylcholine, serotonin, and others), and by prostaglandin E2 and indomethacin. Show more

Keywords: Mollusca, mucous membrane, mucus, slug

DOI: 10.3233/BIR-1987-24608

Citation: Biorheology, vol. 24, no. 6, pp. 571-576, 1987

Authors: Nossal, Ralph

Article Type: Research Article

Abstract: Several noninvasive light scattering techniques are reviewed that can be utilized in rheological studies of mucus and other soft biological matrices. Included are quasielastic light scattering techniques to determine the compressibility moduli of polymer lattices, resonance methods that can be used to measure the shear modulus of weak gels, assays that probe the swelling and contraction of mucin aggregates, and microscope based light scattering techniques to probe gelation within single cells.

Keywords: Light scattering, lattice elasticity, shear modulus, size distributions

DOI: 10.3233/BIR-1987-24609

Citation: Biorheology, vol. 24, no. 6, pp. 577-584, 1987

Authors: Basbaum, Carol B. | Forsberg, Lennart S. | Paul, Annick | Sommerhoff, Christian | Finkbeiner, Walter E.

Article Type: Research Article

Abstract: The glycoconjugate composition of tracheal secretions varies with physiological and pathophysiological parameters. Believing that these differences might be explained by metabolic or regulatory modifications of particular cell types, we have developed strategies for biochemical analysis at the cellular level. We have produced monoclonal antibodies whose determinants arc restricted to a single secretory cell type (serous, mucous, or goblet cell granules, or ciliated cell glycocalyx). By enzyme immunoassay (ELISA), we have characterized four of the antibodies biochemically, and have also used the antibodies as quantitative molecular probes to detect release of antigen from mixed cell explants. Four of the antigens are …carried by carbohydrate moieties of high molecular weight glycoproteins. Western blot analysis shows their molecular weight in reducing gels (SDS-PAGE) to exceed 200 kD. When used in parallel with pulse-chase labeling studies, the antibodies are both more sensitive and specific (than bound radioactivity) in detecting gland or goblet cell secretion in response to autonomic drugs or proteases. We have also isolated and cultured serous gland cells for physiological and biochemical studies. These cells express serous cell phenotype as reflected by ultrastructure, histochemistry, and lysozyme activity. Biochemical analysis of their secretory products reveals glycoconjugate components which are heterogeneous with respect to both molecular weight and charge. Radiolabeled secretory products eluting in the void volume of Sepharose Cl 4B were completely degraded by chondroitinase ABC. This indicates that the major glycoconjugate produced by serous cell is a proteoglycan resembling chondroitin sulfate. Show more

Keywords: glycoconjugates, monoclonal antibodies, serous cell, tissue culture, proteoglycans

DOI: 10.3233/BIR-1987-24610

Citation: Biorheology, vol. 24, no. 6, pp. 585-588, 1987