Cysteine and glutathione concentrations in plasma and bronchoalveolar lavage fluid after treatment with N-acetylcysteine.

Abstract

N-acetylcysteine (600 mg/day) was given to patients by mouth for five days before bronchoscopy and bronchoalveolar lavage to determine whether N-acetylcysteine could increase the concentrations of the antioxidant reduced glutathione in plasma and bronchoalveolar lavage fluid. Bronchoalveolar lavage was performed 1-3 hours (group 2, n = 9) and 16-20 hours (group 3, n = 10) after the last dose of N-acetylcysteine and the values were compared with those in a control group receiving no N-acetylcysteine (group 1, n = 8). N-acetylcysteine was not detected in plasma or lavage fluid. Plasma concentrations of cysteine, the main metabolite of Nacetylcysteine and a precursor of reduced glutathione, were greater in the groups receiving treatment (groups 2 and 3) than in group 1. Cysteine concentrations in lavage fluid were similar in the three groups. Concentrations of reduced glutathione were greater in both plasma and lavage fluid in group 2 than in group 1. These data suggest that Nacetylcysteine given by mouth is rapidly deacetylated to cysteine, with resulting increases in the concentrations of cysteine in plasma and of reduced glutathione in plasma and the airways, which thus temporarily increase the antioxidant capacity of the lung.

Albumin is not suitable as a marker of bronchoalveolar lavage dilution in interstitial lung disease

“…The work also underlines earlier studies by our group [14] and others [5] that have shown that BAL albumin or total protein levels are unsuitable for use as denominators to allow for variable dilution of epithelial lining fluid (ELF), although this is still being done or proposed [15][16][17]. This would include the types of study that have calculated "distribution coefficients" for BAL solutes, by relating ratios of BAL and serum measurements of solutes, with albumin being used as a denominator [25,26].…”

“…Using this approach, together with the analysis of total BAL albumin levels, we have now sought to evaluate the origin of BAL albumin in ILD. This is of particular relevance, since BAL albumin has frequently been suggested as a means of "normalizing" the concentration of other BAL solutes between individuals and groups [15][16][17]. It is perhaps surprising that despite the fact that measurement of BAL solutes is increasingly used as an endpoint in clinical research, there remains little documented work in human subjects evaluating their origin compared with extensive work in animal models and isolated lung preparations [18][19][20].…”

N-Acetylcysteine in the Prevention of Contrast-Induced Nephropathy

“…Bioavailability was Ͻ5%, probably because of extensive first-pass hepatic metabolism. Numerous other investigators have confirmed the low bioavailability of oral NAC including slow-release preparations (25)(26)(27)(28). After intravenous injection, Harada et al found that NAC was highly bound to plasma and tissue proteins, forming various disulfide compounds.…”

UV-B exposure reduces locomotor performance by impairing muscle function but not mitochondrial ATP production

“…Before starting the experiment, a pilot experiment was conducted to determine the NAC concentration necessary to modify GSH concentrations in the tail muscle. Mosquitofish were exposed to four concentrations of NAC (0.0, 0.1, 1.0 and 5 mmol l ) (Bridgeman et al, 1991;Peña-Llopis et al, 2003;Parng et al, 2006;Underwood et al, 2010) in the presence of 3.3 W m −2 UV-B for 1 week. UV-B exposure lasted for 3 h every day from 11:00 to 14:00 h (see below).…”