ABSTRACT
Exposure to arsenic in drinking water is associated with increased respiratory disease. Alpha-1 antitrypsin (AAT) protects the lung against tissue destruction. The objective of this study was to determine whether arsenic exposure is associated with changes in airway AAT concentration and whether this relationship is modified by selenium. A total of 55 subjects were evaluated in Ajo and Tucson, Arizona. Tap water and first morning void urine were analyzed for arsenic species, induced sputum for AAT and toenails for selenium and arsenic. Household tap-water arsenic, toenail arsenic and urinary inorganic arsenic and metabolites were significantly higher in Ajo (20.6±3.5 µg/l, 0.54±0.77 µg/g and 27.7±21.2 µg/l, respectively) than in Tucson (3.9±2.5 µg/l, 0.16±0.20 µg/g and 13.0±13.8 µg/l, respectively). In multivariable models, urinary monomethylarsonic acid (MMA) was negatively, and toenail selenium positively associated with sputum AAT (P=0.004 and P=0.002, respectively). In analyses stratified by town, these relationships remained significant only in Ajo, with the higher arsenic exposure. Reduction in AAT may be a means by which arsenic induces respiratory disease, and selenium may protect against this adverse effect.
Subject(s)
Arsenic/toxicity , Environmental Exposure , Selenium/pharmacology , Sputum/metabolism , Water Pollutants, Chemical/toxicity , alpha 1-Antitrypsin/metabolism , Aged , Aged, 80 and over , Female , Humans , Male , Middle AgedABSTRACT
OBJECTIVE: Selenium (Se) and selenomethionine (Se-Met) have been identified as potential chemopreventive agents of prostate cancer. Using an assay for the speciation (separation and identification) and quantification of selenoamino acids, Se-Met was profiled in serum and prostate tissue from prostate cancer patients. Total Se was measured also. METHODS: Serum and prostate tissue samples were analyzed using high performance liquid chromatography ion channel plasma-mass spectrometry (HPLC ICP-MS). Samples were provided by 25 subjects undergoing radical prostatectomy for the treatment of prostate cancer. RESULTS: The mean serum Se-Met concentration was 59.4 +/- 19.5 ng/ml. Mean total serum Se levels were 133.8 +/- 29.2 ng/ml. Total Se levels in paired samples from the transitional and peripheral zones of the prostate were also compared. Total mean Se levels in peripheral zone tissue was higher than in transitional zone tissue (0.432 +/- 0.212 microg/g versus 0.293 +/- 0.172 microg/g, P = 0.01). Se-Met was detected in the majority of prostate tissues. CONCLUSION: This group of prostate cancer patients had total Se levels in serum and in prostate tissue in a range expected for normal Se intake. There was a significantly higher total Se level found in peripheral versus transitional zone tissues. This is the first time that Se-Met has been detected in prostate tissue.