KEUHKOT, perustietoa , Intrapleuraalinen lubrikanttineste

Keuhkoja ympäröi  keuhkopussi jossa on kaksilehtinen pleurakalvo. Kahden pleurakalvon välillä on lubrikanttinestettä sisältävä tila,  joka vastaa  fysiologisesta liikkuvuudesta rntakehän seinämän ja keuhkon välillä hengitysliikkeiden aikana.
Koetan löytää tästä lubrikanttinesteestä molekulaarista tietoa. Jos muistellaan vanhoja aikoja, kun tu oli yleinen, tähän tilaan muodostui paljon effusiota, jota sitten tyhjejnnettiin ja josta viljeltiin tubibakteeriakin.
Vanhaa hyvää tietoa ensin  vuodelta 1997

https://www.ncbi.nlm.nih.gov/pubmed/9032518

Eur Respir J. 1997 Jan;10(1):219-25. Physiology and pathophysiology of pleural fluid turnover. Miserocchi G¹. Abstract

The pleural space contains a tiny amount (approximately 0.3 mL.kg-1) of hypooncotic fluid (approximately 1 g.dL-1 protein). Pleural fluid turnover is estimated to be approximately 0.15 mL.kg-1.h-1. Pleural fluid is produced at parietal pleural level, mainly in the less dependent regions of the cavity. Reabsorption is accomplished by parietal pleural lymphatics in the most dependent part of the cavity, on the diaphragmatic surface and in the mediastinal regions. The flow rate in pleural lymphatics can increase in response to an increase in pleural fluid filtration, acting as a negative feedback mechanism to control pleural liquid volume. Such control is very efficient, as a 10 fold increase in filtration rate would only result in a 15% increase in pleural liquid volume. When filtration exceeds maximum pleural lymphatic flow, pleural effusion occurs: as an estimate, in man, maximum pleural lymph flow could attain 30 mL.h-1, equivalent to approximately 700 mL.day-1 (approximately 40% of overall lymph flow). Under physiological conditions, the lung interstitium and the pleural space behave as functionally independent compartments, due to the low water and solute permeability of the visceral pleura. Pleural fluid circulates in the pleural cavity and intrapleural fluid dynamics may be represented by a porous flow model. Lubrication between lung and chest wall is assured by oligolamellar surfactant molecules stratified on mesothelial cells of the opposing pleurae. These molecules carry a charge of similar sign and, therefore, repulse each other, assuring a graphite-like lubrication.

Comment in The pleura: the outer space of pulmonary medicine. [Eur Respir J. 1997] PMID: 9032518 DOI: 10.1183/09031936.97.10010219  [Indexed for MEDLINE]  Free full text

mpia tietoja pleuran  mesoteliaalisen joustavuuden parantamisesta  molekulaarisesti lubrikantilla. Jopa  antibiottia, antiviruslääkettä  voidaan asentaa  tällaisen  kantaja-aineen avulla intrapleuraaliseen tilaan pleuralehtien välisen liikkuvuuden parantamiseksi.

1. 5. A. Gouldstone, R. E. Brown, J. P. Butler, and S. H. Loring, “Elastohydrodynamic separation of pleural surfaces during breathing,” Respir. Physiol. Neurbiol. https://doi.org/10.1016/S1569-9048(03)00138-1 137, 97 (2003); Google ScholarCrossref
   

   Elastohydrodynamic separation of pleural surfaces during breathing

   Author links open overlay panelAndrewGouldstone^aRichard EBrown^bJames PButler^aStephen HLoring^b
   https://doi.org/10.1016/S1569-9048(03)00138-1Get rights and content
    Abstract
   To examine effects of lung motion on the separation of pleural surfaces during breathing, we modeled the pleural space in two dimensions as a thin layer of fluid separating a stationary elastic solid and a sliding flat solid surface. The undeformed elastic solid contained a series of bumps, to represent tissue surface features, introducing unevenness in fluid layer thickness. We computed the extent of deformation of the solid as a function of sliding velocity, solid elastic modulus, and bump geometry (wavelength and amplitude). For physiological values of the parameters, significant deformation occurs (i.e. bumps are ‘flattened’) promoting less variation in fluid thickness and decreased fluid shear stress. In addition, deformation is persistent; bumps of sufficient wavelength, once deformed, require a recovery time longer than a typical breath-to-breath interval to return near their undeformed configuration. These results suggest that in the pleural space during normal breathing, separation of pleural surfaces is promoted by the reciprocating sliding of lung and chest wall.
   S. H. Loring, R. E. Browna, A. Gouldstone, and J. P. Butler, “Lubrication regimes in mesothelial sliding,” J. Biomech. https://doi.org/10.1016/j.jbiomech.2004.10.012 38, 2390 (2005). , Google ScholarCrossref