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I I I I I I I I I I I 1 I I I I I I #7q T R: KORTE, ANKE, HANS MICHAEL WAGNER AND GUNTER OBE DATE:1981 TITLE: SIMULTANEOUS EXPOSURE OF CHINESE HAMSTERS TO ETHANOL AND CIGARETTE SMOKE; CYTOGENETIC ASPECTS CITATION: TOXICOLOGY, 20, 237-246, (1981) STUY pESIGN: Chinese hamsters (10-20 weeks old) both male and female, were treated with ethanol, with cigarette smoke and with both. During the experimental period of 12 weeks a control group of animals (C) received water ad libltum, another water drinking group received a cigarette smoke treatment during the last 4 weeks (S). Another group received 20% (v/v) ethanol during the whole experimental period as the only liquid supply (E), and one group with the same ethanol treatment was simultaneously treated with cigarette smoke during the last 4 weeks of the experiment (ES). The groups receiving smoke exposure during the last 4 weeks were exposed for 1 h/day. Those not receiving smoke, groups C and E were also put into the exposure chamber for i hour/day. Smoke was generated by an H. Borgwald smoking machine, containing 5 cigarettes of the total 15 possible. Smoke was sucked into the setup by maintaining a slight negative pressure in the exposure system. The concentrated mainstream smoke was diluted to the desired concentration in a mixing unit. This was effected by continuously monitoring the CO level in the chamber and manually setting a valve regulating the supply of filtered air. The total volume of air flowing through the chamber was - 370 i/h. Depending on the air flow, the number of cigarettes smoked per hour varied slightly: as a mean 30- cigarettes (Ixand: Rothandle" without filter) were used per hour. Biochemical analysis consisted of: blood carboxyhaemoglobin (CO- Hb), enzyme activities for aspartate aminotransferase (GOT) and alanine aminotransferase (GPT) were determined. Cytogenetic analysis were conducted for 2 different cytogenetic end points:, chromosomal aberrations (CA) and sister chromatid exchange (SCE) in the bone marrow cells at the end of the 12'h week. FINDINGSlRESULTS: The concentration of cigarette smoke components during 1 h exposure (ppm) were reported as follows: CO (330-440), NO (6.5-12.4), NO2 (0.4-.12), NH3 (10 - measured at end of 1 hr exposure period). The concentration of B[a]P during smoke exposure was found to be in the range of 600 ng/m3, which corresponds to approximately 7.9 ng B[a]P/cigarette. During the 1 h exposure period the CO-Hb levels of the animals rose from a background level of 0.3 % CO-Hb to a mean value of 23.1%. After 4 weeks of daily exposure, the two groups exposed to cigarette smoke showed a slight increase of the mean haematocrit value, 53.1% as compared with the other two groups 47.9%. The determination of GOT/GPT activity - an indicator for metabolic disturbances of the liver - showed no significant differences between the 4 groups. Only chromatid breaks and isochromatid breaks were found. The rate of chromosomal aberrations was not influenced , neither by ethanol or cigarette smoke alone, nor by slmultaneous exposure to both. The mitotic indices were significantiy elevated in the groups E, S, and ES as compared to control group. The highest mitotic indices were found in the S and ES groups, or those which had been exposed to smoke. There were no differences in the SCE frequencies of all groups. The total range of SCFJmetaphase was nearly the same in all groups. GONCLUSIONS: The investigation of bone marrow cells after 12 weeks with regard to chromosomal aberrations and sister chromatid exchanges revealed not effects. A high mitotic activity was found in smoke treated groups. I