[' ', 'NITROGEN', 'OXIDES', 'IN', 'CIGARETTE', 'SMOKE', 'AND', 'THE', 'EFFECT', 'ON', 'THE', 'SMOKER', 'A', 'survey', 'of', 'the', 'literature', 'on', 'the', 'effects', 'of', 'inspired', 'nitrogen', 'oxides', 'on', 'the', 'mammalian', 'respiratory', 'system', 'revealed', 'that', 'most', 'investigators.', 'studied’', 'only', 'NO,.', 'Experimentally', 'it:', 'is', 'not', 'possible', 'to', 'use:', 'high', 'concentrations:', 'of', 'NO', 'in', 'air', 'without:its', 'oxidation.to', 'NO,.', 'Furthermore,', 'most', 'investigators', 'assumed', 'that', 'NO', 'itself', 'had', 'little', 'effect.', 'Only', 'one', 'report.', 'has.', 'been', 'found.', 'where:', 'an', 'attempt.', 'was:', 'made', 'to', 'be:', 'sure', 'that', 'no', 'NO,', 'contamination', 'existed,', 'and', 'the', 'authors', 'were', 'doubtful', 'if', 'their', 'result', 'was', 'due', 'to', 'NO', 'alone.', 'The', 'following', 'literature', 'citations', 'represent', 'only', 'a.small', 'sample', 'of', 'reports.', 'dealing', 'with', 'the', 'effects', 'of', 'NO,,', 'on', 'the', 'mammalian', 'respiratory', 'system..', 'The', 'majority', 'of', 'the', 'remaining', 'literature', 'deals', 'with', 'acute', 'effects', 'of:', 'high', 'concentrations:', '(>25', 'ppm).', 'LITERATURE', 'Casarett!', 'has', 'reviewed', 'the', 'toxicology', 'of', 'the', 'respiratory', 'tract', 'and', 'includes', 'a', 'brief', 'section', 'on', 'NO,.', '“He', 'cites', 'effects:on', 'ling', 'antibodies,,', 'resistance', 'to', 'disease,', 'macrophages,', 'and.', 'enzymes.', 'He', 'especially', 'mentions', 'the', 'deleterious', 'effect', 'of', 'NO,', 'on.', 'lung', 'surfactant,', 'animal', 'models’', 'for', 'the:', 'study:', 'of', 'NO,', '-induced', 'emphysema,', "and'", 'the', 'effect', 'of', 'NO,', 'on', 'the', 'clearance', 'of.', 'particulate', 'material.', 'Arner,', 'et', 'al.”', 'exposed', 'rats', 'to', 'an', 'average', 'of', '2.9', 'ppm.of', 'NO,', '24', 'hours’', 'a', 'day,', '5', 'days', 'a', 'week,', 'for', '9', 'months.', 'They', 'found', 'an', 'increase:', 'in', 'lung', 'wet', 'weight,', 'a', 'reduction', 'in', 'lung', 'compliance,', 'and.a.', 'reduction', 'in', 'surface-active', 'properties', 'of', 'the:', 'lung', 'wash.', 'A', 'significant', 'decrease', 'in', 'lung', 'lipid', 'content', 'and', 'a', 'marked', 'decrease', 'in', 'percentage', 'of', 'total', 'saturated', 'phospholipid', 'fatty', 'acids', 'was', 'also', 'seen...', 'Purvis', 'and', 'Ehrlich*®', 'studied', 'the', 'resistance.', 'to', 'infection:', 'by', 'Klebsiella', 'pneumoniae', 'by', 'groups', 'of', 'mice', 'exposed', 'for', '2', 'hours.to', '2.5,', '3.5,', 'and', '‘ppm', 'NO,.', 'No', 'change:', 'in', 'susceptibility', 'was', 'seen', 'at', '2.5', 'ppm.', 'At', '3.5:ppm', 'a', 'significant', 'increase:', 'in', 'susceptibility', 'was', 'seen', 'and', 'at', '25', 'ppm', 'there', 'was:', 'an', 'increased', 'mortality', 'rate', 'and', 'a', 'decreased!', 'survival', 'time,', '66epreTeoor']