Pleural Mechanics and Fluid Exchange

Abstract

Lai-Fook, Stephen J. Pleural Mechanics and Fluid Exchange. Physiol Rev 84: 385–410, 2004; 10.1152/physrev.00026.2003.—The pleural space separating the lung and chest wall of mammals contains a small amount of liquid that lubricates the pleural surfaces during breathing. Recent studies have pointed to a conceptual understanding of the pleural space that is different from the one advocated some 30 years ago in this journal (Agostoni E. Physiol Rev 52: 57–128, 1972). The fundamental concept is that pleural surface pressure, the result of the opposing recoils of the lung and chest wall, is the major determinant of the pressure in the pleural liquid. Pleural liquid is not in hydrostatic equilibrium because the vertical gradient in pleural liquid pressure, determined by the vertical gradient in pleural surface pressure, does not equal the hydrostatic gradient. As a result, a viscous flow of pleural liquid occurs in the pleural space. Ventilatory and cardiogenic motions serve to redistribute pleural liquid and minimize contact between the pleural surfaces. Pleural liquid is a microvascular filtrate from parietal pleural capillaries in the chest wall. Homeostasis in pleural liquid volume is achieved by an adjustment of the pleural liquid thickness to the filtration rate that is matched by an outflow via lymphatic stomata.

Effect of histamine on the electrophysiology of the human parietal pleura

“…Trying to overcome the aforementioned we have previously shown that sheep pleural tissue appears to be similar and relative to human in terms of pleural electrophysiology (Hatzoglou et al 2001, Kouritas et al 2008, 2010a, 2010b and its alterations by other hormones such as insulin (Kouritas et al, 2010). This observation is consistent with the fact that various species present similar pleural physiology properties depending on their visceral pleura thickness as is the case for sheep and humans (Lai-Fook, 2004). The effect of histamine in the electrophysiology of sheep visceral and parietal pleura is currently underway.…”

“…Histamine decreases the PD in nostrils (Yang et al 2003) and in blood brain barrier (Hurst andClark, 1998, Butt, 1995) while it increases Cl -conductance and induces K + permeability and Ca 2+ entry via nitric oxide production in vascular cells (Groschner et al 1994). In pleura, histamine influences permeation through cells, given that, since the pleura is considered 'leaky', the paracellular pathway offers unrestricted passage for solutes (Lai-Fook, 2004, Hatzoglou et al 2001). …”

“…Amiloride-sensitive Na + channels and ouabain-sensitive pumps were previously shown to exist in sheep and human pleura (Hatzoglou et al 2001, Sarkos et al 2002 and are considered to interfere with pleural recycling (Hatzoglou et al 2001, Lai-Fook, 2004. Other hormones, such as insulin, have also been shown previously to obstruct this process by blocking such ion transporters (Kouritas et al 2010).…”

The role of the lymphatic system in rabbit models for cancer metastasis research: a perspective from comparative anatomy

“…[1] Starling's hypothesis; [2] Fick's law of diffusion; [3] the serosal pressure associated with organ movement and posture; [4] active transport by mesothelial cells; and [5] a lymphatic drainage system via lymphatic stomata (30,31). Of these factors, the lymphatic drainage system via lymphatic stomata likely plays an important role (30)(31)(32)(33)(34), which may contribute up to approximately 75-80% of the fluid absorption rate in the abdominal and pleural cavities (33,35).…”

“…Of these factors, the lymphatic drainage system via lymphatic stomata likely plays an important role (30)(31)(32)(33)(34), which may contribute up to approximately 75-80% of the fluid absorption rate in the abdominal and pleural cavities (33,35).…”