Adrenergic influence on the permeability of sheep diaphragmatic parietal pleura.

摘要

The pleural fluid is a filtrate of parietal pleura capillaries that crosses the pleural mesothelial barrier and enters the pleural cavity. Under physiological conditions pleural fluid, cells and par-ticulate matter are absorbed mainly by the parietal lymphatics through the lymphatic stomata of the parietal pleura that connect the pleural cavity to the lymphatic capillaries . Most of the researchers up to now seem to agree that the major route for the absorption of pleural fluid from the pleural space is lymphatic absorption, although the exact contribution of other factors assisting this action such as transcytosis, electrolyte-coupled liquid absorption and transpleural pressures needs to be clarified , It is generally accepted that in the diaphragmatic parietal pleura of sheep lymphatic stomas are absent [3, 4]. This suggests that the diaphragmatic parietal pleura contributes to pleural liquid absorption through one of the mechanisms suggested above. Under biologically stressful conditions in vivo, such as pleural effusions, the concentration of adrenaline is elevated (approximately 10~(-7) M) . In a recent study, adrenaline (10~(-7) m) was found to increase the transmesothelial resistance (Rtm) of the sheep costal parietal pleura, probably due to transcellular sodium transport inhibition .