Plasma exudation

Theophylline appears to produce bronchodilation by inhibiting phosphodiesterases, which may also result in antiinflammatory and other nonbronchodilator activity through decreased mast cell mediator release, decreased eosinophil basic protein release, decreased T-lymphocyte proliferation, decreased T-cell cytokine release, and decreased plasma exudation. 

The cysteinyl leukotrienes, particularly LTC4 and LTD4, are potent bronchoconstrictors and cause increased microvascular permeability, plasma exudation, and mucus secretion in the airways. Controversies exist over whether the pattern and specificity of the leukotriene receptors differ in animal models and humans. LTC4-specific receptors have not been found in human lung tissue, whereas both high- and low-affinity LTD4 receptors are present. 

Direct toxic effects such as irritation, inflammation, or increased permeability will bring about symptoms such as the sneeze reflex, nasal discomfort, and hypersecretion with the possibility of underlying pathological changes such as squamous metaplasia, cilia erosion, plasma exudation, epithelial necrosis, inflammatory remodeling, or neutrophil accumulation. Indirect adverse effects can also occur and any alteration to normal nasal homeostasis should be avoided. For example, a reduction in mucociliary clearance can cause rhinitis, sinusitis, and an increased susceptibility to airway infections, and consequently ciliary movement should not be altered by any nasal medication. In the context of absorption enhancers, the rate and extent of recovery of normal nasal epithelial function after nasal administration is a prime consideration. 

Its mechanism of action, however, is not completely elucidated. Kamakura et aL [94] studied the effects of stem bromelain on tlw plasma kallikrein system, bradykinin levels and plasma exudation at the inflammatory site in rats with a kaolin-induced inflammation of an air couch. Bromelain caused a dose-... 

The effect of formoterol 18 micrograms on histamine-induced plasma exudation into sputum has been investigated in 16 healthy subjects in a double-blind, placebo-controlled, crossover study. Plasma exudation into the airways was produced by inhalation of histamine. Sputum was induced by inhalation of hypertonic (4.5%) saline. Induced sputum was obtained at baseline and then at 30 minutes and 8 hours after histamine inhalation. Sputum concentrations of alpha2-macroglobulin were measured as a marker of microvascular-epithelial exudation of bulk plasma. Histamine-induced plasma exudation 30 minutes after placebo was considerably greater than at baseline. The median difference was 11 pg/ml (95% Cl = 0.9, 90) expressed as alpha2-macroglobulin. The... 

Greiff L, Wollmer P, Andersson M, Svensson C, Persson CG. Effects of formoterol on histamine induced plasma exudation in induced sputum from normal subjects. Thorax 1998 53(12) 1010-13. 

Erjefalt, I. and Persson, C.G.A. (1991c). Pharmacologic control of plasma exudation into tracheobronchial airways. Am. Rev. Respir. Dis. 143, 1008-1014. 

Greiff, L., Erjefalt, L, Svensson, C., WoUmer, P., Alkner, U., Andersson, M. and Persson, C.G.A. (1993). Plasma exudation and solute absorption across the airway mucosa. Clin. Physiol. 13, 219-233. 

Kawikova, L, Aiakawa, H., Lofdahl, C.G., Skoogh, B.E. and Lotvall, J. (1993). Bradykinin-induced airflow obstruction and airway plasma exudation effects of drugs that inhibit acetylcholine, thromboxane-A(2) or leukotrienes. Br. J. Pharmacol. 110, 657-664. 

Lotvall, J.O., Elwood, W., Tokuyama, K., Barnes, P.J. and Chung, K.F. (1991a). Plasma exudation into airways induced by inhaled platelet-activating factor effect of peptidase inhibition. Clin. Sci. 80, 241-247. 

Persson, C.G.A. (1986b). The role of plasma exudation in asthmatic airways. Lancet 42, 1126-1128. 

Persson, C.G.A. (1987). Cromoglycate, plasma exudation and asthma. Trends Pharmacol. Sci. 8, 202-203. 

Persson, C.G.A. (1990). Plasma exudation in tracheobronchial and nasal airways a mucosal defence mechanism becomes pathogenic in asthma and rhinitis. Eur. Respir. J. 3 (Suppl. 12), 652s-657s. 

Persson, C.G.A. (1991b). Plasma exudation from tracheobronchial microvessels in health and disease. In The Bronchial Circulation (ed. J. Butler), pp. 443-473. Marcel Dekker, New York. 

Its mechanism of action, however, is not completely elucidated. Kamakura et al. [94] studied the effects of stem bromelain on the plasma kallikrein system, bradykinin levels and plasma exudation at the inflammatory site in rats with a kaolin-induced inflammation of an air pouch. Bromelain caused a dose-dependent decrease of bradykinin levels (measured with the method of Minami et al. [95]) at the inflammatory site and a parallel decrease of the prekallikrein levels in sera [88]. Plasma exudation was also reduced dose-dependently. Bradykinin-degrading activity in sera was elevated after bromelain treatment, but not in the pouch fluid. The authors conclude that bromelain inhibits plasma exudation through inhibition of the bradykinin generation at the inflammatory site via depletion of the plasma kallikrein system. Bromelain also shows a dose-dependent analgesic effect in concanavalin A-injected paws of 5.6 mg/kg i.v.), considered to be due to decrease of high molecular weight kininogen [96]. 

The non-pigmented ciliary epithelium of the ciliary body produces the aqueous (the fluid in the anterior and posterior chambers). The components of the aqueous are quite different from those plasma exudates present in the ciliary body stroma. There are different concentrations of electrolytes, other small molecules, and a restricted set of proteins in low concentrations between the... 

Bronchospasm Plasma exudation V asoconstriction Vasodilation Eosinophil recruitment Cardiodepression... 

The chlorine of the human body amounts to about 0-15 per cent, of the total weight. Concentration is maximal in serum and plasma exudates, gastric juice, spinal fluid, and urine and is minimal in brain and muscle. Urinary chloride depends on the level in the plasma, and falls almost to zero if chloride be withheld from the diet or if the plasma chloride fall below the limiting value of 0-34 per cent. 

Peptidoleukotrienes cause arteriolar constriction, venule dilation, plasma exudation... 

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