Biological Effects of Mount Saint Helens Volcanic Ash on Cultured Human Alveolar Macrophages

Free alveolar macrophages (FAMs) obtained by bronchoalveolar lavage from healthy nonsmoking volunteers were incubated with varying concentrations (0–300 μg/ml) of Mt. Saint Helens volcanic ash obtained from either Portland, Oregon, or Pullman, Washington, to assess the cytotoxic effects of the ash on human lung cells. Trypan dye exclusion techniques were employed for assessment of cell viability. Following the initial 24 hour culture with the Portland ash samples, decreased viability was observed at all ash concentrations (P < 0.001 in all instances), and further decreases in viability were noted at 48 and 72 hours for all concentrations of ash tested (P < 0.001 in all instances). When the Pullman, Washington, ash sample was evaluated, a decrease in cell viability was noted for the 300 μg/ml concentration (P < 0.017) after the initial 24 hours in culture. Further decreases in cell viability were noted only when cells were cultured for longer time intervals (48 and 72 hours) (P < 0.05 in all instances). Differences in cellular response to the 2 ash samples were further investigated by exposing FAMs from a single individual to the 2 different types of ash. These studies demonstrated similar cytotoxic effects of the 2 ash samples at all concentrations and times tested (P < 0.30 in all instances) with the exception of the 100 μg/ml concentrations at 72 hours (P < 0.020). These data suggest that the differences observed between the 2 types of ash in the independent studies are probably related to interindividual variation in FAM response to the ash rather than to differences in the cytotoxicities of the 2 ash samples. Cytotoxicity of the volcanic ash was also compared with other environmentally relevant airborne particulates, such as amosite and chrysotile asbestos, as well as amorphous and crystalline silica. These results demonstrated an intermediate cytotoxic effect of the ash between innocuous amorphous silica and the very cytotoxic chrysotile asbestos. The affinity for volcanic ash to adsorb tritiated benzo(a)pyrene (3H-BaP) was also compared with that of amorphous silica and amosite asbestos. These studies demonstrate that volcanic ash has intermediate adsorption qualities (4.3 ± 0.1; pmoles 3H-BaP adsorbed/μg particulate ± SD) between those of amorphous silica (1.9 ± 1.0) and amosite asbestos (7.8 ± 1.2) (P < 0.05 in all instances). These data suggest volcanic ash exhibits moderate biological properties compared with those of other environmentally important airborne particulates. Whether in vitro studies reflect in vivo response of human lung cells to the ash cannot be determined at this time, and follow-up of assessment of individuals exposed to the ash will be required to assess its long-term effects on pulmonary tissue.

Quantification of CYP2B7, CYP4B1, and CYPOR messenger RNAs in normal human lung and lung tumors

Cytochrome P450 (CYP) enzymes expressed in human lung can metabolize a variety of xenobiotics, drugs, and endogenous compounds. Metabolism of these substrates may lead to their detoxification or activation and may affect the homeostasis of the lung, its susceptibility to disease, response to therapy, and clinical prognosis. We analyzed the expression of CYP2B7, CYP4B1, and NADPH-cytochrome P450 oxidoreductase (OR) mRNAs in normal lung controls, normal lung from lung cancer patients, and lung tumors using the sensitive technique of RNase protection. The mRNAs of CYP2B7, CYP4B1, and OR were detected in all the normal and a majority of neoplastic tissues. The three mRNAs were quantified and found at an average ratio of 0.89, 4.03, and 0.88% relative to actin mRNA in normal lung, respectively. There was no correlation between the levels of expression of the three mRNAs and the histological diagnosis of tumors. The amounts of each of the three mRNAs varied considerably between patients, but analysis of frequency distribution of the levels of CYP2B7 and CYP4B1 mRNAs did not present evidence for genetic polymorphism as a possible source of the observed interindividual variability. Levels of expression of the two P450 mRNAs were reduced (2.3- and 2.4-fold) in the neoplasms compared to normal lung. The level of OR mRNA expression was uniform with no significant differences between normal and neoplastic tissues, and its interindividual variability was the lowest amongst the three mRNAs studied. All mRNAs had increased interindividual variability in neoplastic tissues. Analysis of the patients' smoking histories and the level of CYP2B7, CYP4B1, and OR mRNAs revealed no evidence for their induction by compounds present in cigarette smoke. This study identifies and characterizes lung and lung tumor mRNAs encoding enzymes that may participate in the metabolism of xenobiotics in humans.

Metabolic activation of 4-ipomeanol by complementary DNA-expressed human cytochromes P-450: evidence for species-specific metabolism

4-Ipomeanol is a pulmonary toxin in cattle and rodents that is metabolically activated by cytochromes P-450 (P-450s). P-450-mediated activation of 4-ipomeanol to DNA binding metabolites was evaluated using a vaccinia virus complementary DNA expression system and an in situ DNA-binding assay. Twelve human P-450s and two rodent P-450s were expressed in human hepatoma Hep G2 cells and examined for their abilities to metabolically activate this toxin. Three forms, designated CYP1A2, CYP3A3, and CYP3A4, were able to catalyze significant production of DNA-bound metabolites of 20-, 8-, and 5-fold, respectively, above binding catalyzed by Hep G2 cells infected with wild-type vaccinia virus. These enzymes, with highest activities, are not known to be expressed in human or rodent lung. CYP2F1 and CYP4B1, two enzymes that are expressed in lung, display only modest 3- and 2-fold respective increased abilities to metabolically activate 4-ipomeanol. Two human forms were inactive and seven other human forms showed activities ranging from 0.5- to 2-fold above control level. Surprisingly, rabbit complementary DNA-expressed CYP4B1 was the most active enzyme (180-fold above control) among all P-450s tested in producing DNA-binding metabolites from this mycotoxin. These studies demonstrate a species difference in 4-ipomeanol metabolism and suggest caution when attempting to extrapolate rodent data to humans.

Irradiated nude rat model for orthotopic human lung cancers

The development of improved animal models for biological and preclinical studies of human lung cancer is important because lung cancer is the leading cause of cancer death in the United States. To determine whether the Rowett nude rat could serve as an orthotopic (organ-specific) model of this disease, nude rats (CR: NIH-RNU), with and without 500 rads of prior gamma-irradiation, were implanted intrabronchially with 10(7) cultured cells from 3 human lung cancer lines. Without irradiation, the NCI-H460 large-cell undifferentiated carcinoma had a 54% take-rate, whereas the NCI-H125 adenosquamous carcinoma and A549 adenocarcinoma had take-rates of 7 and 33%, respectively; irradiation increased the respective take-rates to 100, 83, and 90%. In irradiated rats, tumor age versus weight measurements showed progressive growth for all three tumors, with growth rates in the order: NCI-H460 greater than A549 greater than NCI-H125, requiring approximately 3, 5, and 9 weeks, respectively, for average tumor sizes to exceed 500 mg. The small-cell carcinoma cell line NCI-H345 was implanted only into irradiated rats and resulted in more slowly growing tumors. Histopathological study showed all model tumor types to have histological characteristics consistent with the clinical tumors from which the cell lines were derived. Each tumor type had a different growth pattern, with some of the the A549- and NCI-H125-derived tumors metastasizing to contralateral lung and/or regional lymph nodes. There was no evidence for immunological rejection in irradiated, tumor-bearing rats. Nonirradiated, implanted rats without gross tumor exhibited peribronchiolar mononuclear cell infiltration with or without fibrosis, suggesting prior immunological rejection. The successful orthotopic growth of these 4 human lung cancer cell lines in irradiated nude rats suggests that this model could be useful for biological and preclinical studies of human lung cancer, both in intact rats and via ex vivo perfusion of their tumor-bearing lungs.

Metabolic activation of 4-ipomeanol in human lung, primary pulmonary carcinomas, and established human pulmonary carcinoma cell lines

4-Ipomeanol (IPO) is a pulmonary-specific toxin that is metabolically activated by a cytochrome P450 pathway in lung tissue. In this study, IPO metabolism, as determined by measurement of [14C]IPO covalent binding, was evaluated in a diverse sampling of 18 established, human lung cancer cell lines as well as in normal lung tissue and primary lung carcinoma tissue obtained at the time of thoracotomy from 56 patients with lung cancer. [14C]IPO covalent binding in lung cancer cell lines ranged from 248 to 1,047 pmol of bound [14C]IPO per milligram of protein per 30 minutes (mean +/- SE = 547 +/- 62.2). IPO metabolism in normal lung tissue ranged from 12 to 2,007 pmol of covalently bound [14C]IPO per milligram of protein per 30 minutes (mean +/- SE = 549 +/- 60). In lung cancer tissue, values ranged from 0 to 2.566 pmol of covalently bound [14C]IPO per milligram of protein per 30 minutes (mean +/- SE = 547 +/- 60, P greater than .3). When patients were divided into smokers and current non-smokers (no tobacco products smoked for greater than 6 mo), no effects of cigarette smoking were observed for either normal lung tissue or lung tumor tissue (P greater than .1 in all instances). A wide range of IPO metabolic activity was observed among different histological classifications of lung cancer cell lines and of fresh lung cancer tissues. IPO metabolism was simultaneously compared in normal lung tissue and lung cancer tissue from individual patients, but no positive correlation was observed (r = .10; P greater than .30). The results clearly demonstrate a wide range of IPO metabolism in both normal and lung cancer cells and indicate that a wide diversity of human lung cancers possess the metabolic enzyme system(s) necessary for the bioactivation of IPO to a potentially cytotoxic intermediate. Therefore, the continued exploration for any possible therapeutic potential of IPO in patients with lung cancer appears warranted.

Expression of CYP1A1 gene in patients with lung cancer: evidence for cigarette smoke-induced gene expression in normal lung tissue and for altered gene regulation in primary pulmonary carcinomas

The major polycyclic aromatic hydrocarbon inducible-cytochrome P4501A1 gene (CYP1A1) is presumed to be important in pulmonary carcinogenesis and toxicology because its product, the cytochrome P4501A1-dependent (CYP1A1-dependent) monooxygenase, transforms selected xenobiotics (including polycyclic aromatic hydrocarbon procarcinogens in cigarette smoke) to potent carcinogenic metabolites. CYP1A1 messenger RNA (mRNA) expression has not, however, been previously demonstrated in human pulmonary tissue. This report defines CYP1A1 gene expression in normal lung tissue and primary pulmonary carcinoma tissue obtained at thoracotomy from 56 patients with lung cancer. When Northern blot hybridization analyses were performed, 17 of 19 (89%) and zero of five (0%) samples of normal lung tissue from active cigarette smokers and nonsmokers, respectively, expressed the normal 2.8-kilobase CYP1A1 mRNA. In addition, a time-dependent decrease in expression of the CYP1A1 gene was noted in normal lung tissue from individuals who were former smokers, with a decrease in expression occurring as early as 2 weeks following cessation of cigarette smoking. Expression became undetectable in all patients who had stopped smoking more than 6 weeks prior to study. When CYP1A1 gene expression was evaluated in lung cancers, mRNA levels were detectable in one of four (25%) tumors from nonsmokers; two of 24 (8%) tumors from former smokers; and seven of 15 (47%) tumors from cigarette smokers. In addition, an approximately 10-kilobase CYP1A1 RNA species, which was not detectable in normal lung tissue, was observed in five of ten (50%) of the lung cancers that expressed the CYP1A1 gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for elevated levels of histamine, prostaglandin D2, and other bronchoconstricting prostaglandins in the airways of subjects with mild asthma

Histamine and certain cyclooxygenase products of arachidonic acid have been implicated as mediators of inflammation and are potent constrictors of human airways. Because asthma may represent manifestations of chronic inflammation of the airways, the levels of histamine and six prostanoid mediators were measured in airway fluids obtained by bronchoalveolar lavage (BAL) of 12 normal, 11 allergic rhinitic, and 15 asymptomatic, allergic asthmatic subjects. Simultaneous profiling of prostanoid mediators in individual samples was performed using gas chromatography-mass spectrometry. Levels of PGD2, 9 alpha,11 beta-PGF2 and PGF2 alpha were 12 to 22 times higher in asthmatic than in normal subjects (p less than 0.01), with concentrations in airway fluids of asthmatic subjects after correction for dilution of 3.8, 0.5, and 1.4 nanomolar, respectively. Levels of PGD2 and 9 alpha,11 beta-PGF2 were increased nearly tenfold in asthmatic subjects compared with those in rhinitic subjects (p less than 0.01), distinguishing the subjects with lower airway disease from those with another atopic condition. Histamine levels were increased fourfold in asthmatic subjects compared with those in normal subjects (p less than 0.001); however, similar increases were found in rhinitic subjects. We conclude that elevated levels of multiple mediators with potent bronchoconstricting activity are present in the airways of subjects with mild asthma, indicating that even mild disease is associated with evidence of airway inflammation. The interactions of bronchoconstricting mediators and airway inflammation may play important roles in the pathogenesis of asthma.

Altered regulation of the cytochrome P4501A1 gene: novel inducer-independent gene expression in pulmonary carcinoma cell lines

The cytochrome P450 (CYP) systems catalyze the metabolic transformation of a wide variety of xenobiotics including procarcinogens present in cigarette smoke condensate as well as atmospheric pollutants. The CYP1A1 isoenzyme is of particular interest because it has been implicated as a risk factor in the etiology of lung cancer in heavy cigarette smokers. The identification and expression of the structural CYP1A1 gene in either normal human lung or lung cancer cells has not been reported. Because of its potential significance in human lung cancer, we investigated the expression of the CYP1A1 structural gene in 24 established human lung cancer cell lines including 15 non-small cell (eight adenocarcinomas, three large cell undifferentiated carcinomas, two bronchioloalveolar cell carcinomas, and two squamous cell carcinomas) and nine small cell lung carcinomas. CYP1A1 mRNA was detected in 14 of 15 (93%) of the non-small cell lung carcinoma cell lines examined following 24-hour treatment with benz[a]anthracene (BA) and in nine of 15 (60%) of the non-small cell lines cultured without an inducer in the medium. When the small cell lung cancer lines were evaluated for CYP1A1 gene expression, two of nine (22%) expressed detectable CYP1A1 mRNA in both BA-induced cell cultures and constitutive (control) cultures. A positive correlation was noted between BA-induced CYP1A1 mRNA levels and the corresponding aryl hydrocarbon hydroxylase activity expressed as absolute BA-induced enzyme activity (r = 0.74; P less than .01; n = 24), which further demonstrated that CYP1A1 mRNA expression reflects CYP1A1 enzyme activity in the individual cell lines. These observations represent the first known demonstration of constitutive (non-induced) CYP1A1 gene expression in human cells and suggest altered regulation of the CYP1A1 gene in selected lung cancer cell lines. These human pulmonary carcinoma cell lines, which have documented regulatory defects, could be useful for further identification of the mechanisms associated with CYP1A1 gene regulation.

A human tumor lung metastasis model in athymic nude rats

Experimental lung metastases regularly developed in athymic Han:rnu/rnu Rowett rats after i.v. injection of LOX human malignant melanoma cells. When 5 x 10(5) tumor cells were injected into 4-week-old rats, 89% of the animals died of lung tumors, with a mean survival time of 18 days. With 5- and 6-week-old rats, however, the fraction of animals that died decreased to 80 and 46%, with mean survival times of 35 and 38 days, respectively. The number of detectable lung colonies in each animal was about 35 in 5- and 6-week-old animals, compared to nearly 300 in 4-week-old rats. In the latter, a correlation was found between the number of tumor cells injected and the number of detectable lung colonies. The capacity of the LOX tumor to grow s.c. and to form experimental lung metastases was, by and large, similar in young nude rats and in nude mice, and no significant difference in morphology between the different tumors in the two species was seen. A high-resolution radiographic method was used to visualize lung colonies in the nude rats, and single tumors with diameters as small as 2-4 mm could be detected. By this method, for the first time, the effect of chemotherapy on a human tumor growing in a visceral organ of a rodent host could be followed by repeat X-ray examinations, mimicking a situation commonly faced in the clinic. This procedure may prove particularly useful for experimental chemotherapy studies, and may be extended to other human tumors that frequently metastasize to the lungs. Indications were obtained that some host-specific differences in tissue-preferenced growth might exist, a possibility that will be further explored.

4-Ipomeanol: a novel investigational new drug for lung cancer

4-Ipomeanol (IPO) is the first agent to undergo preclinical development at the National Cancer Institute (NCI) based principally on a specific biochemical-biological rationale for clinical investigation as an antineoplastic agent targeted against lung cancer. This disease-specific development of IPO was initially stimulated by observations that the compound was activated by metabolism, preferentially within the mammalian lung, specifically within bronchiolar Clara cells, and that its predominant toxicity was to the lung in most species. IPO is inactive or only minimally active against most conventional antitumor test systems. However, some human lung cancer cell lines, as well as a variety of fresh human lung tumor biopsy specimens, have been shown to be capable of mediating the in situ biotransformation of IPO to a potentially cytotoxic intermediate. In this report, the biochemistry, metabolism, preclinical pharmacology, and toxicology of IPO are reviewed and the clinical development plans for this unique and challenging new agent are presented.

Evidence for prostanoid biosynthesis as a biochemical feature of certain subclasses of non-small cell carcinomas of the lung as determined in established cell lines derived from human lung tumors

Detectable levels (greater than or equal to 0.2 pmol/10(6) cells) of one or more prostanoid species resultant to calcium ionophore A23187-induced biosynthesis from endogenous arachidonic acid were distributed in 28 cell lines derived from different histological classes of lung tumors as follows: large cell undifferentiated carcinoma (3 of 3 cell lines); adenosquamous carcinoma (1 of 2 cell lines); squamous cell carcinoma (0 of 2 cell lines); adenocarcinoma (9 of 10 cell lines); bronchioloalveolar cell carcinoma (2 of 2 cell lines); and small cell carcinoma (1 of 9 cell lines). Using the mean levels of 9 alpha,11 beta-prostaglandin F2, prostaglandin F2 alpha, prostaglandin D2, prostaglandin E2, thromboxane B2 and 6-keto-prostaglandin F1 alpha as an index of prostaglandin H (PGH) synthase activity, the distribution in cell lines representative of the different histological classes of human lung tumors exhibiting PGH synthase activity exceeding mean values greater than or equal to 2 pmol/10(6) cells was as follows: large cell undifferentiated carcinoma (3 of 3 cell lines), adenosquamous carcinoma (1 of 2 cell lines), adenocarcinoma (8 of 10) cell lines), bronchioloalveolar cell carcinoma (2 of 2 cell lines) and small cell carcinoma (0 of 9 cell lines). Three different prostanoid species accumulated to mean levels greater than or equal to 2 pmol/10(6) cells. Prostaglandin E2 levels exceeded 2 pmol/10(6) cells in 14 of the 16 cell lines in which this prostanoid accumulated to detectable levels. Cumulative levels of prostaglandin F2 alpha exceeded 2 pmol/10(6) cells in 9 of the 15 cell lines in which prostaglandin F2 alpha reached detectable levels. Detectable levels of thromboxane B2 were observed in five cell lines with thromboxane B2 accumulation exceeding 2 pmol/10(6) cells in two of the five cell lines. 9 alpha,11 beta-prostaglandin F2 and 6-keto-prostaglandin F1 alpha accumulated to detectable levels in the culture medium of one cell line, while prostaglandin D2 accumulation to detectable levels was observed in two cell lines. Stimulation of cultured human lung tumor cells exhibiting PGH synthase activity greater than or equal to 2 pmol/10(6) cells in the presence of 10(-5) M exogenous arachidonic acid resulted in a 2- to 4-fold increase in the accumulation of individual prostanoids, while the inclusion of a 10(-5) M exogenous concentration of arachidonic acid failed to stimulate detectable prostanoid production in human lung tumor cells in which PGH synthase activity was not previously expressed.(ABSTRACT TRUNCATED AT 400 WORDS)

Profiles of prostaglandin biosynthesis in normal lung and tumor tissue from lung cancer patients

prostaglandin (PG) biosynthetic profiles from endogenous arachidonic acid were determined by capillary gas chromatography-mass spectrometry in matched fresh normal lung (NL) and lung cancer (LC) tissue fragments obtained from 42 individual LC patients at the time of diagnostic thoracotomy. The histological diagnoses represented were squamous cell carcinoma (N = 20), adenocarcinoma (N = 7), small cell carcinoma (N = 4), mixed cell carcinoma (N = 2), bronchioloalveolar cell carcinoma (N = 2), large cell undifferentiated carcinoma (N = 3), bronchial carcinoid (N = 1), and metastatic tumors (N = 3). When PG biosynthesis was determined in NL tissue separately, low mean levels of PGE2 and PGF2 alpha (less than 2 pmol/mg protein/15 min), intermediate levels of PGD2 and 6-keto-PGF1 alpha (6KPGF1 alpha) (2-7 pmol/mg protein/15 min), and high levels of thromboxane B2 (TXB2) (greater than 7 pmol/mg protein/15 min) were observed. There was no particular correlation with cigarette smoking history and PG biosynthesis in NL. When PG production in LC tissue was evaluated separately, high levels of PGE2, PGF2 alpha, and 6KPGF1 alpha as well as TXB2 and low levels of PGD2 were noted. In addition, LC tissue from cigarette smokers demonstrated elevated levels of PGE2, 6KPGF1 alpha, and TXB2 when compared to current nonsmokers with LC (P less than 0.05 in all instances). Simultaneous comparison of PG production in matched LC and NL tissue from individual patients indicated increased biosynthesis of PGE2 and PGF2 alpha and low levels of PGD2 in LC compared to NL tissue (P less than 0.05 in all instances; paired, two-tailed, Student's t test). Individual comparison of PG biosynthesis according to LC histological cell type revealed that PGE2 and PGF2 alpha were consistently elevated in all four common primary LC histological cell types, the only exception being large cell undifferentiated carcinoma. Interestingly, this latter LC histological cell type presented a unique profile with lower levels of PGE2 and PGD2 in LC than in NL tissue (P less than 0.05 in both instances). In addition, the biosynthesis of all 5 PGs studied was consistently higher in primary than metastatic adenocarcinomas of the lung (P less than 0.05 in all instances). No differences were observed in NL and LC tissue for the major LC histological cell types when PGD2, TXB2, or 6KPGF1 alpha biosyntheses were compared. These findings indicate that the profiles of PG biosynthesis in LC and NL tissue from individual patients may differ substantially. These differences may reflect, in part, contributions to the PG biosynthetic profile unique to malignant cells.

Evidence for thromboxane biosynthesis in established cell lines derived from human lung adenocarcinomas

Thromboxane B2 (TxB2) is the stable nonenzymatic hydrolysis product of thromboxane A2, a substance implicated in the initiation of the facilitative role of thrombocytes in the metastatic process. TxB2 was isolated from protein-free culture medium of cell lines Calu-3, Calu-6, A549, and A549/Asc-1, derived from human lung adenocarcinomas. TxB2 and other 20-carbon fatty acid cyclooxygenase products synthesized from exogenous and endogenous arachidonic acid were identified by their characteristic retention indices and fragmentation of electron-capture derivatives of unlabeled and deuterium-labeled products during combined capillary gas chromatography-mass spectrometry. TxB2 comprised 2 to 6% of 20-carbon fatty acid cyclooxygenase products biosynthesized from endogenous arachidonic acid in calcium ionophore A23187-stimulated Calu-6 and A549/Asc-1 cells and 16 to 25% of these products in Calu-3 and A549 cells. The addition of 10(-5) M exogenous arachidonic acid to the cultured cells resulted in a 2- to 3-fold increase in TxB2 and bisenoic prostanoid production with no significant alterations in the proportion of TxB2 production. Prostaglandin E2 and prostaglandin F2 alpha, two prostanoids that can be formed either enzymatically or nonenzymatically from prostaglandin H2, accounted for greater than 75% of isolatable 20-carbon fatty acid cyclooxygenase products synthesized from endogenous and exogenous arachidonic acid.

Comparison of intrapulmonary, percutaneous intrathoracic, and subcutaneous models for the propagation of human pulmonary and nonpulmonary cancer cell lines in athymic nude mice

The propagation efficiencies, growth patterns, histological appearances, and roentgenographic demonstration of tumors derived from six continuous human pulmonary tumor cell lines implanted intrathoracically (i.t.) and intrabronchially (i.b.) were compared with the conventional s.c. implantation method at three different tumor cell inocula (N = 184, i.b.; N = 185, i.t.; N = 180, s.c.). A tumor-related mortality of 100% was noted when the six different human lung tumor cell lines, including A549 adenocarcinoma, NCI-H125 adenosquamous carcinoma, NCI-H460 large cell undifferentiated carcinoma, NCI-H69 small cell carcinoma, and NCI-H358 and NCI-H322 bronchioloalveolar cell carcinomas, were implanted i.b. at a 1.0 x 10(6) tumor cell inoculum. A similar (92%) tumor-related mortality was observed when these same lung tumor cell lines were implanted i.t. at a 1.0 x 10(6) tumor cell inoculum (P greater than 0.10), whereas minimal (5%) tumor-related mortality was noted when cells from the six different cell lines were implanted s.c. (P less than 0.001). In addition, a dose-dependent, tumor-related mortality was noted for either i.t. or i.b. implantation when lower (1.0 x 10(5) or 1.0 x 10(4] tumor cell inocula were employed. Histological characteristics and growth patterns of tumors propagated employing the three implantation techniques were closely comparable for all three propagation methods and, in all instances, histological appearances of the tumors were representative of the current tumor cell lines from which they were derived. Approximately 30% of the lung tumors propagated i.t. grew in the chest wall and/or in the lung parenchyma as well as in the pleural space. In contrast, tumors propagated i.b. grew predominantly in the lung parenchyma. When five nonpulmonary human tumor cell lines (including U251 glioblastoma, LOX amelamontic melanoma, HT-29 colon adenocarcinoma, OVCAR 3 ovarian adenocarcinoma, and adriamycin-resistant MCF-7 breast adenocarcinoma) were propagated i.b. or i.t., there was considerable site-specific variability in tumor-related mortality depending on the tumor type. These data demonstrate that both the i.b. and i.t. models should be useful for the in vivo propagation and study of certain human pulmonary and nonpulmonary carcinomas as well as being advantageous for future studies of cancer biology and developmental therapeutics.

Profiling of bisenoic prostaglandins and thromboxane B2 in bronchoalveolar fluid from the lower respiratory tract of human subjects by combined capillary gas chromatography-mass spectrometry

Methods for the profiling of prostaglandin D2 (PGD2), prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), 15(S),9 alpha,11 beta-trihydroxyprosta-5Z,13E-dien-1-oic acid (9 alpha,11 beta-PGF2), 6-keto-prostaglandin F1 alpha (6kPGF1 alpha), and thromboxane B2 (TxB2) in bronchoalveolar lavage (BAL) fluids from human subjects by combined capillary gas chromatography-mass spectrometry are described. Aliquots (5 ml) of BAL fluid obtained using a standardized lavage protocol were extracted on octadecylsilyl silica cartridges after addition of 0.8 to 2.0 nanograms of tetradeuterated analogs of PGE2, PGF2 alpha, and 6kPGF1 alpha as internal standards. Eluted analytes and internal standards were prepared for vapor phase analysis by sequential reactions resulting in the formation of methyloxime-pentafluorobenzyl ester-trimethylsilyl ether derivatives. The derivatized analytes were detected by simultaneous monitoring of ions at six different masses characteristic for each of the derivatized prostanoids. The samples were of adequate purity for identification and quantitation of each of the prostanoids with detection limits of 0.1 to 0.2 picograms of each analyte per milliliter of BAL fluid. The time required for analysis of each sample was approximately 30 minutes. Standard curves of unlabeled species of the six prostanoids extracted after addition to BAL fluid were linear over a range from subpicogram to nanogram quantities. The differences between the amounts of prostanoid added and the amounts of prostanoid measured were typically less than 19%, and the intra-assay coefficients of variation for repeated measurements of a single sample were less than 20%. PGE2, PGD2, PGF2 alpha, and TxB2 were detectable in BAL fluids from normal subjects with levels of each of these compounds being less than 2.6 picograms/ml. BAL fluids from patients with lung disease presented qualitative and quantitative profiles of prostanoids markedly different than those from normal subjects. These analytical methods provide a basis for in vivo comparisons of prostanoid profiles in the lower respiratory tract of man and should be readily adaptable for use in a variety of clinical studies.

Novel intrapulmonary model for orthotopic propagation of human lung cancers in athymic nude mice

A major impediment to the study of human lung cancer pathophysiology, as well as to the discovery and development of new specific antitumor agents for the treatment of lung cancer, has been the lack of appropriate experimental animal models. This paper describes a new model for the propagation of human lung tumor cells in the bronchioalveolar regions of the right lungs of athymic NCr-nu/nu mice via an intrabronchial (i.b.) implantation procedure. Over 1000 i.b. implantations have been performed to date, each requiring 3 to 5 min for completion and having a surgery-related mortality of approximately 5%. The model was used successfully for the orthotopic propagation of four established human lung cancer cell lines including: an adenosquamous cell carcinoma (NCI-H125); an adenocarcinoma (A549); a large cell undifferentiated carcinoma (NCI-H460), and a bronchioloalveolar cell carcinoma (NCI-H358). When each of the four cell lines was implanted i.b. using a 1.0 X 10(6) tumor cell inoculum, 100 +/- 0% (SD) tumor-related mortality was observed within 9 to 61 days. In contrast, when the conventional s.c. method for implantation was used at the same tumor cell inoculum, only minimal (2.5 +/- 5%) tumor-related mortality was observed within 140 days (P less than 0.001). Similarly, when a 1.0 X 10(5) or 1.0 X 10(4) cell inoculum was used, a dose-dependent, tumor-related mortality was observed when cells were implanted i.b. (56 +/- 24% or 25 +/- 17%) as compared with the s.c. method (5 +/- 5.7% or 0.0 +/- 0%) (P less than 0.02 and P less than 0.05, respectively). Most (greater than 90%) of the lung tumors propagated by i.b. implantation were localized to the right lung fields as documented by necropsy and/or high-resolution chest roentgenography techniques which were developed for these studies. The intrapulmonary model was also used for establishment and propagation of xenografts derived directly from enzymatically digested, fresh human lung tumor specimens obtained at the time of diagnostic thoracotomy and representing all four major lung cancer cell types as well as a bronchioloalveolar cell carcinoma. Approximately 35% (10 of 29) of the fresh primary human lung tumor specimens and 66% (2 of 3) of tumors metastatic to the lung were successfully propagated i.b. at a 1.0 X 10(6) tumor cell inoculum, whereas only 20% (1 of 5) of the specimens were successfully grown in vivo via the s.c. route from a 1.0 X 10(7) tumor cell inoculum.(ABSTRACT TRUNCATED AT 400 WORDS)

Profiling of prostaglandin biosynthesis in biopsy fragments of human lung carcinomas and normal human lung by capillary gas chromatography-negative ion chemical ionization mass spectrometry

Methods for the profiling of prostaglandin F2 alpha (PGF2 alpha), prostaglandin D2 (PGD2), prostaglandin E2 (PGE2), thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (6KPGF1 alpha) biosynthesis in tissue samples of clinical origin by capillary gas chromatography-negative ion chemical ionization mass spectrometry (CGC-NICIMS) are detailed. Aliquots (25 microliter 1) of incubates (1 ml volume) of human lung carcinoma and normal human lung tissue fragments (total protein content = 0.2 to 2.0 mg) were derivatized for vapor phase analysis in the presence of 0.75 to 1.60 ng of tetradeuterated analogs of PGE2, PGF2 alpha and 6KPGF1 alpha without prior extraction and/or chromatography. The derivatized analytes and internal standards were detected by simultaneous monitoring of ions at six different masses characteristic for each of the derivatized prostanoids. The inter-sample and intra-sample coefficients of variation for the assay method were typically less than 12%. The analysis of biological samples was completed with less than 2.5% of each derivatized sample per injection. The samples were of adequate purity for the identification and quantitation of each of the eicosanoids. The methods described in this report are highly selective and highly sensitive with detection limits of 0.1 to 0.2 picograms per injection. The analytical procedures provide the basis for comparisons of the qualitative and quantitative profiles of prostaglandin biosynthesis and should be adaptable for use in a variety of biological and clinical studies.

In vitro cytotoxicity of chrysotile asbestos to human pulmonary alveolar macrophages is decreased by organosilane coating and surfactant

Human pulmonary alveolar macrophages were used to quantitate the cytotoxic effect of surface-altered chrysotile asbestos. Little difference was observed in mortality between chrysotile asbestos that was surface-treated to a 42% extent by a hydrophobic organosilane or untreated chrysotile. Little or no effect on mortality was observed when human pulmonary alveolar macrophages were cultured with untreated chrysotile or acid-leached asbestos in the presence of 10 mM dipalmitoyl lecithin. However, when human pulmonary alveolar macrophages were cultured with a hydrophobically-treated (to a 42% or 95% extent) chrysotile asbestos in the presence of 10 mM dipalmitoyl lecithin, a statistically significant decrease in mortality was observed compared to untreated chrysotile. No mutagenic activity was observed when V79 cells were cultured with acid-leached, or 42% hydrophobically-treated chrysotile asbestos, even when human pulmonary alveolar macrophages were included as an activation source. The 95% hydrophobically-treated and acid-leached chrysotile also exhibited decreased binding of benzo[a]pyrene compared to untreated chrysotile asbestos.

Gamma interferon is spontaneously released by alveolar macrophages and lung T lymphocytes in patients with pulmonary sarcoidosis

Gamma interferon (IFN gamma) is a potent immune mediator that plays a central role in enhancing cellular immune processes. This study demonstrates that while lung mononuclear cells from normal individuals spontaneously release little or no interferon (less than 10 U/10(6) cells per 24 h), those from patients with pulmonary sarcoidosis spontaneously release considerable amounts (65 +/- 20 U/10(6) cells per 24 h, P less than 0.02 compared to normals). Furthermore, cells from patients with active disease release far more interferon than those from patients with inactive disease (101 +/- 36 compared to 24 +/- 8 U/10(6) cells per 24 h, P less than 0.02). Characterization of this interferon using acid sensitivity, specific antibody inhibition, and target cell specificity criteria demonstrated that it was almost entirely IFN gamma. This spontaneous release of IFN gamma appeared to be compartmentalized to the lung of these patients in that their blood mononuclear cells spontaneously released little or no IFN gamma (P less than 0.02, compared to sarcoidosis lung mononuclear cells) and no IFN gamma was detected in their serum. Both lung T lymphocytes and alveolar macrophages contributed to the spontaneous release of IFN gamma by lung mononuclear cells from sarcoid patients; purified preparations of T lymphocytes and alveolar macrophages from these patients spontaneously released similar amounts of IFN gamma (56 +/- 21 and 32 +/- 11 U/10(6) cells per 24 h, respectively, P greater than 0.3). At least one role for IFN gamma in the pathogenesis of sarcoidosis appeared to be related to activation of alveolar macrophages, as alveolar macrophages recovered from patients with active disease spontaneously killed [3H]uridine-labeled tumor cell targets (17.7 +/- 4.5% cytotoxicity compared with 2.8 +/- 0.9% in normals, P less than 0.02) and purified IFN gamma enhanced the ability of alveolar macrophages from sarcoidosis patients with inactive disease to kill similar targets (P less than 0.001, compared to alveolar macrophages cultured in medium alone). Treatment of sarcoid patients with corticosteroids, a therapy known to suppress the activity of the disease, caused a marked reduction in the level of spontaneous IFN gamma release by lung mononuclear cells compared with untreated patients (P less than 0.02), which suggests that the effectiveness of corticosteroid therapy in controlling active pulmonary sarcoidosis may, at least in part, be due to suppression of IFN gamma release.

Cryopreservation of human pulmonary alveolar macrophages

Human pulmonary alveolar macrophages (PAM) from 30 patients with a variety of pulmonary diseases were tested for their ability to undergo cryopreservation. The cells were cryopreserved and stored under liquid nitrogen for intervals of 2, 4, 6, 8, or 12 wk, then assayed for viability (using the trypan dye exclusion method as well as the NADH-dependent cytochrome c reductase (cytochrome c) assay) and cellular function (as documented by the measurement of in vitro aryl hydrocarbon hydroxylase (AHH) induction by benzanthracene (BA) and by quantitation of PAM particulate phagocytosis). These results demonstrated no decrease in PAM viability after 2 wk of cryopreservation compared with that of the control cells (p greater than 0.30, paired, 2-tailed t test). However, PAM viability decreased slightly compared with the 0-time (p less than 0.003 in all instances) when cells were stored for intervals of 4, 6, 8, or 12 wk. In addition, cells demonstrated no further decrease in viability after being cryopreserved for as long as 12 wk, thawed, and cultured for as long as 48 h compared with the 0-time control cells (p greater than 0.10 in all instances). Similarly, when AHH induction was fluorometrically quantitated in PAM cultured for 24 h, there was no decrease in BA-induced AHH levels after a 2-wk cryopreservation period. However, AHH levels decreased slightly compared with those in the 0-time control cells (p less than 0.004), when PAM were stored for longer intervals of 4, 6, or 8 wk. The phagocytic activity of cryopreserved PAM was also quantitated using amorphous silica as a substrate.(ABSTRACT TRUNCATED AT 250 WORDS)

Variations in aryl hydrocarbon hydroxylase activities in mitogen-activated human and nonhuman primate lymphocytes

A fluorometric assay for the cytochrome P-450-dependent enzyme system, aryl hydrocarbon hydroxylase (AHH), was performed in mitogen-activated human lymphocytes from over 300 different humans and from 64 baboons. Results reveal: a) an average interindividual variation in AHH activity of approximately 0.25 (coefficient of variation); range of activities among humans and baboon subjects of approximately 40-fold; c) both genetic and environmental determinants of interindividual variation, and d) high AHH activity in humans associated with primary lung cancer. Confirmation of these results awaits the development of improved methods for phenotyping humans and for prospective cancer patient studies. DNA probes might be employed in future studies to determine specific mRNA content, and to search for DNA polymorphisms in and near the human cytochrome P-450 gene.

Chronic acetazolamide intoxication

Severe acidosis associated with acetazolamide therapy is rare. We report the first case in which plasma and whole blood acetazolamide concentrations were measured. A 61 year-old patient receiving oral acetazolamide for treatment of glaucoma presented with a 7 day history of declining mental status. The patient was lethargic and oriented only to name. The respiratory rate was 36 per minute in a Kussmaul pattern with arterial blood gases revealing a pH of 7.23, pO2 68 mmHg, paCO2 14 mmHg and bicarbonate 6 mEq/L. Serum creatinine was 3.1 mg%, Cl 126 mEq/L, and anion gap 15. Urine pH was 6.0. Infection and other causes of acidosis and bicarbonate loss were excluded, and he was discharged with normal mental status and improving acid-base balance 18 days after admission. Acetazolamide concentrations four days after the last dose were 26.38 mcg/ml and 38.84 mcg/ml in serum and whole blood, respectively. The serum half-life was 34 hours, compared to a range of 1.5 to 6 hours in subjects with normal renal function. Monitoring acetazolamide concentrations may be useful in adjusting dosage and preventing toxicity in patients with decreased renal function.

Positive correlation between high aryl hydrocarbon hydroxylase activity and primary lung cancer as analyzed in cryopreserved lymphocytes

Blood samples from closely monitored patients at the Veterans Administration Hospital in Houston, Texas, were collected, coded, and sent to Microbiological Associates over an 8-month period. Lymphocytes were isolated and cryopreserved at -190 degrees. Lymphocyte samples were simultaneously thawed, phytohemagglutinin activated, and analyzed for benz(a)anthracene-induced aryl hydrocarbon hydroxylase (AHH) levels, [3H]thymidine incorporation, and reduced nicotinamide adenine dinucleotide-dependent cytochrome b5 (cytochrome c) reductase activity. Determinations were made at both 96 and 120 hr in culture, and peak activities were compared among a total of 51 individuals who expressed such lesions as squamous cell carcinomas (22%), adenocarcinomas (14%), oat cell carcinomas (6%), chronic obstructive pulmonary disease (22%), and other nonmalignant diseases. Of the 14 highest AHH/cytochrome c activities observed, all were found in patients with primary lung cancer. Mean AHH/cytochrome c activities were 0.89 for lung cancer patients (a total of 21) and 0.47 for noncancer patients (a total of 30) (p less than 0.001). No relationship was observed between AHH/cytochrome c activity and age of patient, numbers of cigarettes smoked, family history of cancer, location or histological type of tumor, or level of phytohemagglutinin blastogenesis ([3H]thymidine cpm/cytochrome c). Whether the higher AHH levels are the cause or the result of the primary lung cancer remains to be determined.

Reassessment of the relationship between aryl hydrocarbon hydroxylase and lung cancer

Aryl hydrocarbon hydroxylase was measured in cultured human lymphocytes induced with benzathracene and in pulmonary alveolar macrophages induced in situ in cigarette smokers. Considered separately, neither lymphocyte AHH nor macrophage AHH levels were distinctly different in either noncancer or lung cancer patients. Considered simultaneously, lymphocyte and macrophage AHH levels are quite different in noncancer and lung cancer patients. The lung cancer patient group was seen to contain a significantly higher percentage of persons with high levels of AHH than did an age-matched group of noncancer patients, (P less than 0.001), when more than one tissue was assayed to determine the individual's enzyme levels.

Reversed-phase separation of benzo[a]pyrene metabolites by thin-layer chromatography

The use of reversed-phase thin-layer chromatography for the separation of benzo[a]pyrene metabolites has been investigated. Two systems are described for the separation of the major metabolites of benzo[a]pyrene, including sulfate and glucuronide conjugates.

Scanning electron microscopic examination of human asbestos bodies

Asbestos bodies represent the product of the macrophage's attempt to detoxify inhaled asbestos fibers. The process of asbestos body maturation was examined by scanning electron microscopy of material isolated from lungs of former asbestos workers. The results suggest that the progression from a membrane-bound, smooth coating of the fiber, to the typically beaded form may be caused by cracking and subsequent erosion due to the inspiratory and expiratory forces of the lung on the asbestos body.

Asbestos body phagocytosis by human free alveolar macrophages

Phagocytosis of asbestos bodies by human free alveolar macrophages (FAMs) was documented employing light microscopy. This process was more carefully studied utilizing scanning electron microscopy (SEM) which demonstrated morphological and surface membrane changes in FAMs following phagocytosis of asbestos bodies. FAM viability was also evaluated following 24--72-h incubation of cells with asbestos bodies at a final concentration of 250 micrograms/ml. Slight, but significant, cytotoxicity was observed following the initial 24-h culture period (P = 0.032, paired, 2-tailed t-test). No further cytotoxicity was observed, however, when cells were further incubated for 48-h and 72-h intervals (P greater than 0.05 in all instances). These studies demonstrate asbestos bodies are readily phagocytized by cultured FAMs, and are only slightly cytotoxic to these human lung cells.

Patterns of benzo[alpha]pyrene metabolism in normal human pulmonary alveolar macrophages

Pulmonary alveolar macrophages (PAMs) obtained by bronchopulmonary lavage from 6 normal non-smoking volunteers were incubated with [3H]-benzo[alpha]pyrene to ascertain the normal metabolism and conjugation of polycyclic aromatic hydrocarbons. Through the use of a crude glucuronidase preparation, both glucuronic acid and sulfate conjugates were examined. Phenols and quinones were identified by high-pressure liquid chromatography as the principal free metabolites formed during 1 h incubation with benzanthracene induced PAMs. In addition, phenols and quinones were major substrates utilized by these cells for conjugation during the incubation period. The ranges of benzo[alpha]pyrene metabolites produced by PAMs from non-smokers were compiled and the variation in production as well as detoxification of proximate carcinogenic benzo[alpha]pyrene metabolites are presented.

Induction of aryl hydrocarbon hydroxylase in human peripheral blood lymphocytes by chrysene

Many of the polycyclic aromatic hydrocarbons (e.g., benzo[a]pyrene (B[a]P), benzanthracene (BA), 3-methylcholanthrene (3-MC)) are not only carcinogenic, but also induce AHH in human tissues. Recently, chrysene has been implicated as an etiologic determinant of chemical carcinogenesis. Here we describe the ability of chrysene to induce AHH in cultured human lymphocytes. Lymphocytes were obtained from 9 healthy subjects, divided into 2 sets, and cultured in duplicate, triplicate, or quadruplicate for 48 h. Chrysene (25 microM final concentration) in acetone was then added to the induced culture set and the control set received acetone alone. Lymphocytes were then cultured an additional 24 h before harvesting. AHH was quantitated by a fluorometric analysis of the phenolic metabolites produced by incubating the lymphocytes with B[a]P for 35 min. A significant increase in enzyme induction occurred in the chrysene-induced cultures compared with control (non-induced) cells (one-tailed student t-test; P less than 0.001). It was also observed that the interindividual variation in AHH inducibility seen with other PAHs is also observed with chrysene.

Aryl hydrocarbon hydroxylase activity in pulmonary alveolar macrophages and lymphocytes from lung cancer and noncancer patients: a correlation with family histories of cancer

Aryl hydrocarbon hydroxylase (AHH) activity was measured in pulmonary alveolar macrophages (PAMs) and peripheral blood lymphocytes from cigarette smokers with and without primary lung cancer. Frequency distribution analysis of AHH induction ratios for the two groups revealed an increased number of individuals in the lung cancer patient group with high lymphocyte induction values (P less than 0.05). A similar increase was not shown for high-PAM AHH values in lung cancer patients (P greater than 0.2). When individual PAM and lymphocyte AHH values were compared between noncancer and lung cancer patients, a positive correlation was observed for noncancer patients (r=0.195, P less than 0.001), but no correlation of these values was noted for lung cancer patients. The lung cancer patients were divided into three subgroups of patients showing (I) high PAM and low lymphocyte AHH levels, (II) low PAM and low lymphocyte AHH levels, and (III) low PAM and high lymphocyte AHH levels. When the incidence of family history of cancer was compared for these subgroups, no family cancer history was recorded for persons in subgroup II; however, individuals in subgroups I and III presented family cancer history incidence of 9.5% and 39.3%, respectively. Patients in group III averaged 6 years younger than those in group I. These data suggest that familial factors may be identified among lung cancer patients and that these factors appear to associate as either a cause of an effect with the capacity of pulmonary alveolar macrophages and lymphocytes to be induced for AHH. The data support the hypothesis that high AHH values may be characteristic of lung cancer patients but show that enzyme values determined from a single tissue, either PAMs or lymphocytes, may not be appropriate for showing whether high AHH inducibility is correlated with lung cancer.

Aryl hydrocarbon hydroxylase induction in mitogen-stimulated lymphocytes by benzanthracene or cigarette tars adsorbed to asbestos fibers

Human mitogen-stimulated lymphocytes, cultured in the presence of amosite asbestos (AS), demonstrated a slight increase in aryl hydrocarbon hydroxylase (AHH) activity compared with non-induced (control) cultures (P = 0.005). A much greater increase in enzyme activity occurred following addition of the inducers benzanthracene (BA) or cigarette tars (CT) to cell cultures (P less than 0.001 in both instances). Significant enzyme induction also occurred when AS fibers were first preincubated with CT or BA, washed with acetone, then added to lymphocyte cultures (P less than 0.003 in all instances). This increase in AHH activity was not as great, however, as the induction observed when BA or CT was added to cell cultures. No further increase in enzyme activity was noted when AS and CT or AS and BA were simultaneously added to culture lymphocytes (P greater than 0.070 in all instances). The results demonstrate that polycyclic aromatic hydrocarbons (PAH), such as BA and other components of CT, are adsorbed and transported by amosite AS particles. These AS-PAH complexes are capable of inducing AHH in cultured human lymphocytes.

Comparison of aryl hydrocarbon hydroxylase induction in cultured blood lymphocytes and pulmonary macrophages

Aryl hydrocarbon hydroxylase induction was studied in cultured peripheral blood lymphocytes and pulmonary alveolar macrophages from 15 smokers and 8 nonsmokers with a variety of pulmonary diseases. Enzyme levels in lymphocytes from cigarette smokers cultured in medium without an inducing agent were 57+/-6 mU/10(6) cells (mean+/-SEM), while enzyme levels in lymphocytes from nonsmokers were 20+/-2 mU/10(6) cells (P < 0.001). When lymphocytes were cultured in the presence of the inducing agent, benzo-(a)anthracene, enzyme activity was increased to 168+/-23 mU/10(6) cells in smokers' cells and 99+/-22 mU/10(6) cells in lymphocytes from nonsmokers (P < 0.04). When noninduced enzyme values in cultured macrophages were compared, smokers' cells had enzyme levels of 45+/-5 mU/10(6) cells, whereas nonsmokers had enzyme activity of 24+/-2 mU/10(6) cells (P < 0.002). However, pulmonary macrophages from smokers or nonsmokers, cultured in the presence of benzo(a)-anthracene, had similar levels of induced enzyme activity (P > 0.1). A positive correlation was observed for nonsmokers (r = 0.596, P > 0.1 <0.2) or smokers (r = 0.640, P < 0.04), when enzyme values for noninduced cultures of macrophages and lymphocytes from individual patients were simultaneously compared. Enzyme values for macrophages and lymphocytes cultured in the presence of an inducer also revealed a positive correlation for individual smokers (r = 0.801, P < 0.001) or nonsmokers (r = 0.785, P < 0.01). Inducibility (expressed as fold-induction) for macrophages and lymphocytes from individual patients was also positively correlated (r = 0.889, P < 0.001 for nonsmokers and r = 0.942, P < 0.001 for smokers). These results indicate that the capacity for aryl hydrocarbon hydroxylase induction is similar whether tested in lymphocytes or pulmonary macrophages from this group of pulmonary disease patients.

Induction of aryl hydrocarbon hydroxylase in human pulmonary alveolar macrophages and peripheral lymphocytes by cigarette tars

Cigarette smoking is associated with alterations in pulmonary alveolar macrophages (PAMs), including increased cytoplasmic inclusions and induction of the aryl hydrocarbon hydroxylase (AHH) system. Nonpigmented PAMs from nonsmokers were able to ingest and accumulate pigment from lysed PAMs of smokers, however, this pigment did not induce AHH activity in either PAMs or peripheral lymphocytes. In contrast, the cigarette tars significantly induced AHH levels in PAMs and in peripheral lymphocytes from either nonsmokers or smokers. This provides further evidence that components in cigarette smoke can explain the in vivo induction of AHH documented in cells from smokers.