CHARACTERIZATION OF CAROTENOID, VITAMIN-A, AND ALPHA-TOCOPHERAL LEVELS IN HUMAN LUNG-TISSUE AND PULMONARY MACROPHAGES

Increasing evidence suggests that beta-carotene, retinol (vitamin A), and alpha-tocopheral (vitamin E) may have important protective effects in the lung. However, surprisingly little is known about their storag e and metabolism in human lung. Levels of beta-carotene, retinol, and alpha-tocopherol in human lung tissues and bronchoalveolar lavage (BAL ) cells were determined with reverse-phase high-pressure liquid chroma tography (HPLC). Fresh lung tissue, serum, and dietary questionnaires were obtained from 21 patients undergoing open lung surgery, and BAL c ells from 12 of these patients. Dietary and serum levels of carotenoid s, beta-carotene, retinol, and alpha-tocopherol were consistent with p reviously reported values. Lung tissue levels of total carotenoids, be ta-carotene, retinol, and alpha-tocopherol were respectively 0.34 +/- 0.36 mu g/g, 0.13 +/- 0.27 mu g/g, 0.15 +/- 0.06 mu g/g, and 9.60 +/- 4.86 mu g/g tissue. Levels of these nutrients were also measured in BA L cells to establish potential markers for their lung tissue levels. C orrelations between serum, BAL-cell, tissue, and dietary levels of the nutrients were determined. Lung tissue levels of total carotenoids, b eta-carotene, and alpha-tocopherol, but not retinol, correlated well w ith their serum levels. Lung tissue levels of retinol and alpha-tocoph erol correlated with their BAL-cell levels. These studies demonstrate quantifiable levels of retinol, alpha-tocopherol, and total carotenoid s or beta-carotene in human lung tissue and BAL cells, and show that s erum and/or BAL-cell levels of these nutrients can potentially be used to predict their lung tissue levels.