Biochemical effects on combined gases of nitrogen dioxide and ozone. I. Species differences of lipid peroxides and phospholipids in lungs

In the present study, changes of lipid peroxides, phospholipids and antioxidant levels in lungs of 4 animal species exposed to the combined gases of NO2 and O3 were compared. Male mice, hamsters, rats and guinea pigs were used. Lipid peroxides were increased significantly in the lungs of mice and guinea pigs exposed to the combined gases, but not in hamsters and rats. Changes of alpha-tocopherol (VE) contents were slight. On the other hand, non-protein sulfhydryl (NPSH) contents were increased strikingly, especially in hamsters, but were not increased in guinea pigs. Phosphatidylcholine (PC) contents were increased and phosphatidylethanolamine (PE) contents were decreased by the exposure to the combined gases, with the order guinea pig greater than mouse greater than rat. In hamsters no changes were seen. The changes of fatty acid composition in guinea pigs and mice were marked, the increases of palmitate and palmitolate and the decreases of polyunsaturated fatty acid were especially characteristic. These changes in phospholipid class and fatty acid composition may be a "a kind of adaptation phenomenon" to avoid further lipid peroxidation. On the other hand, the changes in hamsters and rats were small. The results show the existence of species differences in lipid peroxide formation by exposure to the combined gases of NO2 and O3. They were found to be related to the contents of antioxidants and the compositions of phospholipids and their fatty acids.

Histologic assessment of bronchial anastomotic healing in canine lung transplantation

Postoperative wound healing of the bronchial anastomosis was studied in dogs with autotransplantation (20 dogs, 7 days to 6 years postoperatively) and allotransplantation (62 dogs, 5 to 174 days postoperatively) of the left lung. In the group undergoing lung allotransplantation, the relationship among three histologic parameters was studied: the grade of lung allograft rejection, the degree of changes in the epithelium, and submucous lymphocyte infiltration along the donor bronchus within approximately a 0.5 cm area distal to the anastomosis. In lung autotransplantation, mucosal continuity began to be observed 1 week postoperatively. Mucosal continuity and apparent collagen formation on any bronchial contiguous site were demonstrated in most animals studied more than 3 weeks postoperatively. Bronchial anastomotic healing tended to be slower in lung allotransplantation than in autotransplantation, although a mucosal continuity at the anastomosis was sporadically observed in immunosuppressed dogs surviving more than 3 weeks postoperatively with a lung allograft. There were significant rank correlations among the three histologic parameters, which showed that lung allograft rejection is closely connected with wound healing of the bronchial anastomosis in lung allotransplantation. Meticulous mucosal approximation is most necessary during bronchial anastomotic procedures. Establishment of an exact method for early monitoring of lung allograft rejection is absolutely necessary for lung allotransplantation.

Lipid peroxidation and antioxidative protection mechanism in rat lungs upon acute and chronic exposure to nitrogen dioxide

This work was done to clarify the relation between the changes of lipid peroxidation and the activities of antioxidative protective enzymes in lungs of rats exposed acutely, subacutely, and chronically to nitrogen dioxide. It was confirmed that the activities of the antioxidative enzymes to protect cells from oxidative stress increased in an early phase, and then the activities decreased gradually. Lipid peroxides increased once in an early phase and then returned to the control level; thereafter, lipid peroxides increased gradually again. Lipid peroxidation as measured by ethane exhalation increased significantly with 0.04, 0.4, and 4 ppm nitrogen dioxide exposure for 9, 18, and 27 months, and a dose-response relationship was clearly observed. The temporal changes of lipid peroxidation varied inversely with that of the activities of antioxidative protective enzymes. From these results, it was suggested that the increments of antioxidative protective enzyme activities in an early phase were complementary effects to protect cells from damage by lipid peroxides which were increased by nitrogen dioxide exposure, and that the complementary effects are lost in later phases of life-span exposure. Finally, loss of such protective complementary effects might relate to some chronic diseases in lungs. Therefore, the temporal changes described above are important characteristics in chronic exposure of air pollutants.

A rat model for monitoring homograft rejection of the lung

A new surgical procedure was devised for the experimental homograft of the lung. The pulmonary artery and vein and bronchus were anastomosed under the operation microscope using interrupted sutures in group W (30 outbred Wistar rats) and continuous sutures in group F (7 inbred F344/Ducrj Rats). Mean ischemia time during the operation was 95.3 +/- 10.3 min in the group W and 55.6 +/- 5.8 in group F. Eight out of 30 rats (27%) of group W and all rats of group F survived more than 24 hr after the surgery. Pulmonary functions of grafted lungs were evaluated by serial x-rays and the perfusion ratio was 27.4 +/- 11.6% (mean +/- S.D.) in group W and 25.4 +/- 7.7% in group F. A patent opening of the hilar anastomosis in these rats was confirmed at autopsy. This model with continuous suture would be useful for the rat lung transplantation.

Studies on the biochemical effects of nitrogen dioxide. IV. Relation between the change of lipid peroxidation and the antioxidative protective system in rat lungs upon life span exposure to low levels of NO2

This study examined the relation between lipid peroxidation and the antioxidative protective system in lungs of rats exposed to low levels of nitrogen dioxide (NO2). JCL:male Wistar rats were exposed to 0, 0.04, 0.4, and 4 ppm NO2 for 9, 18, and 27 months. Lipid peroxidation measured by TBA method, increased significantly in the 4 ppm NO2 group of the 9-month exposure and in the 0.4 and 4 ppm NO2 groups of the 18-month exposure. The activity of glutathione peroxidase measured with hydrogen peroxide as substrate decreased significantly in the 4 ppm NO2 group of the 9-month exposure and in the 0.4 and 4 ppm NO2 groups of the 18-month exposure. Furthermore, the activities of two glutathione S-transferases, aryl and aralkyl S-transferase, also decreased in the 0.4 and 4 ppm NO2 groups of the 18-month exposure, but not in any groups of the 9-month exposure. The activity of glutathione peroxidase measured with cumene hydroperoxide as substrate did not show any significant changes in any NO2 group. The activities of glucose-6-phosphate dehydrogenase and glutathione reductase were significantly higher than those in the control group for the 9-month exposure. In the 18-month exposure, however, they showed a tendency to return to control level. The activities of superoxide dismutase and disulfide reductase upon NO2 exposure for 9 and 18 months were not different from control values. To confirm that lipid peroxidation was increased with greater NO2 concentrations and exposure times, ethane and pentane exhalation in breath as an index of lipid peroxidation was examined. Ethane exhalation increased significantly following 0.04, 0.4, and 4 ppm NO2 exposure for 9 and 18 months. Furthermore, ethane formation of rats exposed to 0.04 and 0.4 ppm NO2 for 27 months also increased to twice the control level. On the other hand, after exposure to 4 ppm NO2 for 27 months, ethane levels returned to control level. Pentane formation increased significantly only in the 0.04 and 0.4 ppm groups in the 18-month exposure. Ethane exhalation in rats exposed to 0.04, 0.12, and 0.4 ppm NO2 for 9 and 18 months was similar. These results suggested that the antioxidative protective ability was decreased with prolonged exposure, while formation of cytotoxic lipid peroxides was increased.(ABSTRACT TRUNCATED AT 400 WORDS)

A ten-year experience with surgical resection for patients with metastatic lung tumors

Removal of metastatic lung tumor was performed for 27 patients in a period from January, 1972 to December, 1981. They included 22 carcinomas and 5 sarcomas. Diagnosis as having lung metastasis was made after removal of the primary tumor in 18 patients and at the time of the first detection of the primary tumor in 4 patients. In 5 patients the operation for the metastatic tumor preceded that for the primary malignancy. Metastatic tumors were localized in one lobe in 13 patients. Thirteen of the 27 patients underwent lobectomy and 14 received other types of operation, with or without hilar and/or mediastinal lymphnode dissection. Four patients underwent bilateral thoracotomy. Survival rates at 3 and 5 postoperative years of the group of patients who underwent the operation for primary malignancy first were both 49 percent. The number of lesions removed or the type of operation did not seem to have correlations with the survival rate. Patients whose tumor-free interval was more than 40 months tended to survive longer than those who had an interval less than 40 months. The group with a tumor doubling time of more than 50 days showed a higher survival rate than the group with a doubling time of less than 50 days. Of the 4 patients thoracotomized bilaterally 2 are alive for 20 and 34 months postoperatively, while the other 2 died at 20 and 65 months after the operation. In the selected patients with metastatic lung tumors, surgical treatment can be conducted with a reasonably good result, even though the metastatic malignancy is multiple or bilateral.

Relationship between survival times of rats exposed to lethal level of nitrogen dioxide and arylhydrocarbon hydroxylase activity in lungs

A previous paper has shown that survival times of rats exposed to lethal levels of NO2 were prolonged by administration of enzyme-inducing agents prior to NO2 exposure, and that the survival time of female rats was longer than that of male rats. In order to investigate a mechanism on prolongation of survival times by administration of enzyme-inducing agents and on sex-difference, a relationship between survival times and microsomal enzyme activity in lungs of rats administered enzyme-inducing agents was examined. The survival times of rats exposed to 65 ppm NO2 were prolonged with increase of 3MC doses, and AHH activity in lungs of rats rose with increase of 3MC doses. A significant correlation between the survival time and AHH activity was observed. Induction of AHH activity of female rats administered 3MC was higher than that of male rats. NADPH-dependent cytochrome c reductase activity in lungs of male and female rats did not change with 3MC administration, and a significant relationship between the survival time and NADPH-dependent cytochrome c reductase activity was not observed. These results suggest that cytochrome P1-450 system in lung microsomes may have protective action against the toxicity of NO2.

Biochemical studies on strain differences of mice in the susceptibility to nitrogen dioxide

Strain differences of mice in their susceptibility to nitrogen dioxide (NO2) were examined by measuring the activities of antioxidative protective enzymes, and the amounts of antioxidants and lipid peroxides in lungs. Four strains of mice: ICR, BALB/c, ddy and C57BL/6 were used in this study and their LC50 values after exposure to NO2 for 16 hr were: 38, 49, 51 and 64 ppm, respectively (1). Genetic strain differences were observed in the enzyme activities, the antioxidant contents and lipid peroxide contents among these four different strains. The activities of glutathione peroxidase (GPX), glutathione S-transferase, and superoxide dismutase (SOD), and the contents of non-protein sulfhydryls (NPSH), alpha-tocopherol (alpha-Toc) and total lipids in lungs of the four strains were related to their LC50, while TBA reactants in lungs of the four strains were inversely related to their LC50. After exposure to 20 ppm NO2 for 16 hr, the activities of the protective enzymes and the contents of NPSH decreased, while the level of alpha-Toc increased markedly. The activities of GPX, 6-phosphogluconate dehydrogenase, SOD and disulfide reductase, and the contents of NPSH, alpha-Toc and total lipids were also related to their LC50. On the other hand, TBA reactants increased higher than those of the control groups and were inversely related to their LC50. These results suggest that the protective enzymes and the antioxidants are important factors at defence mechanism in lungs to NO2 and that the intensity of the protective systems in pigmented strains is generally greater than that in albino strains.

Studies on biochemical effects of nitrogen dioxide. II. Changes of the protective systems in rat lungs and of lipid peroxidation by acute exposure

This work was done to clarify the relation between the change of lipid peroxidation and the protective systems in lungs after NO2 exposures. JCL:Wistar 8-wk-old male rats were exposed continuously to 10 ppm NO2 for 2 wk. Lipid peroxidation, measured by ethane exhalation in the breath of the rats and by the reaction of thiobarbituric acid with lung homogenates, increased to a maximum at 3 d after a decline at 1 d, and then returned to the initial level (of d 0). Activities of glutathione peroxidase (GPx), glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), disulfide reductase (DSR), and superoxide dismutase (SOD) in the 105,000 X g supernatant of lung homogenates were depressed slightly at 1 d. Thereafter, they increased significantly to their maximum levels from 5 to 10 d, and these maximum levels were maintained until d 14. The pattern of change of these protective enzymes was symmetric to that of lipid peroxidation after 3 d. The order of the ratio of the increased value to the initial value was G6PD greater than DSR greater than 6PGD greater than GR greater than GPx greater than SOD. The time course of nonprotein sulfhydryls was similar to that of the protective enzymes. In contrast, the amounts of vitamin E increased to a maximum at 2 d and then returned to the initial level. The periodic change of vitamin E was similar to that of lipid peroxidation rather than that of the protective enzymes. These results suggest that the ability of the enzyme systems in lungs to protect against NO2 fluctuated in a complex manner and the activities of the protective enzymes varied inversely with lipid peroxidation.

Effects of acute nitrogen dioxide exposure on swimming performance of mice

To evaluate the acute effects of NO2 on the physical performance of experimental animals, male mice 15-16 wk old were exposed to 5, 10, 20, or 40 ppm NO2 for 24 h, and forced swimming endurance time (FSET), the changes in FSET during the postexposure days, lung wet weight, lung water content, and blood lactate level were examined. FSET of mice exposed to NO2 at 10, 20, and 40 ppm decreased immediately after exposure, FSET of mice exposed to 5 ppm NO2 did not change immediately after exposure, but a significant decrease was observed from d 1 to d 4 after exposure. FSET recovered to the initial control level after 5-6 d, 7-8 d, and over 9 d in mice exposed to NO2 at 5, 10, and 20 ppm, respectively. Lung wet weight of mice exposed to 20 and 40 ppm NO2 and lung water content of mice exposed to 10, 20, and 40 ppm NO2 increased with dose. A negative relation was demonstrated between FSET and lung wet weight and between FSET and lung water content. Without forced swimming exercise, the blood lactate level of mice exposed to 5 ppm NO2 was almost equivalent to that of control mice, but the blood lactate level of the exposed mice significantly increased immediately and 24 h after forced swimming exercise for 4 min.

Studies on biochemical effects of nitrogen dioxide: I. Lipid peroxidation as measured by ethane exhalation of rats exposed to nitrogen dioxide

This research was in order to follow the periodic fluctuation of lipid peroxidation by a new method in rats exposed to nitrogen dioxide. Wistar male rats were examined for lipid peroxidation as demonstrated by ethane exhalation. In rats continuously exposed to 10 ppm nitrogen dioxide for 2 weeks, the amount of ethane exhaled fluctuated in a complex manner during the exposure. Ethane exhalation decreased slightly after the first day of exposure and then increased rapidly. The maximal values were observed after the fourth day of exposure and then decreased gradually to the initial level. Furthermore, the activity of glutathione peroxidase in lungs of rats exposed to 10 ppm nitrogen dioxide varied symmetrically against the change of ethane formation. Similar changes in ethane exhalation were observed in rats exposed to the lowest levels of nitrogen dioxide (0.4, 1.2 and 4.0 ppm) for 4 months. Compared to 10 ppm nitrogen dioxide exposure for 14 days, the characteristics in rats exposed to the low levels (0.4-4.0 ppm) of nitrogen dioxide were: the decline of ethane formation, the delay in alterations, and the tendency toward gradual increase during the longer period exposure.

Visual discrimination in monkey with removal of inferotemporal cortex

The monkey with removal of the inferotemporal cortex (IT monkey) showed a marked impairment of discrimination between a pair of visual pattern stimuli, which consisted of different patterns on the identical background [corrected] plaques. The present study showed that an IT monkey, unlike an unoperated normal monkey, performed discrimination with utilizing a partial cue within the whole configuration of pattern stimuli. In contrast to a general concept, the present finding appears to raise a question as to whether the IT monkey can perceive or identify visual pattern.