Normobaric oxygen can enhance protein captation by the lymphatic system in healthy humans.

Abstract

has been advocated for a long time. Several beneficial effects of NBO have been demonstrated, one of which is the faster elimination of tissue nitrogen bubbles. During DCS occurrence, a cascade of intravascular reactions has been demonstrated. These inflammatory reactions occur within minutes of the onset of DCS, and involve the precipitation of proteins on the gas-bubble interface, causing a stabilization of the intravascular and tissue bubbles. Little is known about the elimination of the protein-coated bubbles except that they are smaller than the obstructive ones, thus allowing them to pass through the circulation and probably enter the interstitium during the extravasation phase, subsequent to hypoxia. Also known is that the proteins can denature. This may cause the accumulation of free fat globules found during decompression sickness (1, 2). Fat emboli have been observed in several studies of decompression sickness and can contribute to central nervous system damage(3). As interstitial proteins are evacuated by the lymphatic circulation, we wanted to investigate if NBO enhances lymphatic activity and thus, protein elimination (4, 5). The rationale relations between edema and hypoxia are clear if we think of the augmented distance between capillaries and the presence of “oxidative burst” during inflammation involving bacterial activity (6). Furthermore, the presence of a large number of mitochondria in the lymphatic endothelium shows a marked oxidative metabolism for the activation of lymphatic contractile properties. It has been shown that reactive nitrogen species can reduce the contractile properties of the lymphatic vessel. Hence, denitrogenation has been proposed as a positive action on lymphatic contraction (7).