흡연 및 니코틴이 백혈구 염색체에 미치는 영향에 관한 연구

Abstract

[한글]담배연기 응축물에서 Lasnitzki(1968)는 hydrocarbon이 다량 포함된 fraction을 태아의 페배양에 처리하면 세포증식을 유발하여 암으로 변형하는 것을 관찰하여 담배연기중 hydrocarbon이 폐암유발의 원인으로 생각하였다.

Nicotine이 심박동수, 수축력, 관상동맥유출 양(coronary flow)등에 작용이 있는 것은 이미 알려진 사실이나(Burn, 1960; Greenspan, 등 1969) nicotine이 암을 일으킨다는 보고는 아직 없고 다만 Boyland(1968)가 nicotine의 대사물인 nicotine N-onides와 c0otini

ne이 방광암을 일으킬 수 있다고 제의하였고, 발암작용의 접적 역할에 대해서는 Bock(1976)에 의해서 보고된 바 있다. 또한 nicotine을 임신 마우스에 주입하면 마우스의 탸자에 치사작용과 기형을 유발하는 것도 알려졌다(Nishimura와 Nakai, 1958).

흡연이 혈액속의 백혈구에도 영향을 줄 것을 예측하여 Obe와 Herha(1978)는 과잉흡연자를 상대로 백혈구의 염색체를 조사한 결과 염색체 이상이 많이 발견되었고, 그러나 Husgafvel-Pursiainen 등(1980)는 염색체 이상을 발견하지 못하였다고 반대된 보고를 하였다. 또한 Lambert등(1978), Bela Krishna Murthy(1979), Husgafvel-Pursiainen등(1980)은 흡연가의 백혈구에서 자매염색분체교환이 증가된 것을 보고하였으나 Hollander등(1978)와 C

rossen 및 Morgan(1980)은 헙연가와 비흡연가의 백혈구에서 자매염색분체교환율간에 아치가 없었다고 보고하고 있다. Hopkin 과 Evans(1979)은 담배의 돌연변이 작용을 구명하고자 담배연기 응축물을 사람의 백혈구에 처리하여 염색분체교환을 봄으로서 DNA에 미치는

영향을 조사하였다.

본 연구에서는 첫째, 만성 혹은 과잉 흡연가의 백혈구 염색체의 이상을 조사하고 둘째, nicotine과 담배연기 응축물(CSC)이 세포분열이나 백혈구 염색체에 미치는 영향을 배양세포에서 조사하여 이제까지의 엇갈린 보고를 정리하는 동시에 보다 구체적으로 인체에서

와 배양세포에 시도하였다. 비흡연자 남녀 10명과 흡연자 남녀 13명을 선택하였다. 흡연자는 하루에 10∼50개비까지 2년에서 36년동안 흡연한 사람들로 평균 연령 47.7세였다.

Moorhead등(1960) 방법으로 백혈구를 배양하여 염색체 이상을 조사하였고 Perry와 Wolff(1974)의 Fluorescence plus Giemsa방법으로 자매염색분체 교환빈도를 조사하였다. 배양한 백혈구를 여러 농도의 nicotine과 CSC로 18시간 처리하여 세포분열빈도(mitotic index), 염색체이상 및 자매염색분체 교환빈도를 조사하여 다음과 같은 결과를 얻었다.

1. 흡연자에서 염색체이상과 염색분체교환 빈도가 비흡연자에 비해서 높았다.

2. 비흡연자에서만 고령에서 염색체이상이나 자매분체교환 빈도가 높았고 흡연자에서는 연령과 관계가 없었다.

3. 남녀차이 혹은 흡연 연수와는 관계없이 하루에 흡연하는 담배수의 증가에 따라 염색체이상과 염색분체교환이 증가되었다.

4. Nicotine과 담배연기 응축물 처리군에서 강한 분열억제작용이 나타났다.

5. NIcotine처리군에서는 염색체이상을 유발하지 않았으나 담배연기 응축물 처리군에서는 흡연자 백혈구배양 실험군에서 높은염색체 이상을 나타냈다.

이상의 결과를 종합하여 보면 흡연이 염색체에 이상을 일으키는 것이 확인되었츠며, 연령, 남녀 및 흡연연수와는 관계없이 흡연하는 담배양의 증가에 따라 염색체이상이 증가되며 nicotine은 세포분열 억제작용이 있을 뿐이고 담배연기 응축물이 염색체이상을 일으키는 것으로 사료되었다.

[영문]Smoking causes a variety of disabilities in man, and between one-half and one-third of all cigarette smokers die as a result of their smoking(WHO, 1975; Doll and Peto, 1976). There is strong epidemiological evidence that tabocco smoke causes cancer in humans(Auerbach et al 1961; Kerr et al 1965; Wynder and Hoffmann, 1967). This carcinogenicity has been confirmed by the results of experiments with animal(Wynder and Hoffmann, 1968).

Although nearly 3,000 compounds have been identified in cigarette smoke, only a few have been related to specific health hazards. Of the harzardous components, however, smoke condensate, carbon monoxide and nicotine poses by far the greatest danger. Smoke condensate is a mixture of many chemicals and is commonly understood to contain most smoke carcinogens. Cigarette smoke condensates(CSC), especially the neutral fraction, have been demonstrated to have tumor-initiating activity on mouse skin tests and in mammalian and human cells in vitro(Wynder and Hoffmann, 1968; Lasnitzki, 1968; Benedict et al 1975). Nicotine is, among other things a so-called mitotic poison(Mainx,1924; Brock et al, 1939; sited by Nishimura and Nakai, 1958). Also Nishimura and Nakai(1958) reported that nicotine skeletal system when it is administered during pregnancy. However, there is no clear evidenct that nicotine is related to lung cancer except that nicontine acts as a carcinogenic stimulus(Bock, 1976).

Lambert et al(1978) have recently examined the frequencies of sister-chromatid exchanges(SCE) among the peripheral lymphocytes of cigarette smokers and foud that they had a significantly higher SCE frequency than non-smokers. A similar result was reported by Bela Krishy Murthy(1979) and Husgafvel-pursiainen et al(1980). However, hollander et al(1987) and Crossen and Morgan(1980) reported that there was no difference in the SCE rate betwiin smokers and nonsmokers. A further cytogenetic study has been reported by Obe and Herha(1978) and they found that heavy cigarette smokers had an increased number of chromosomal aberrations when compared with nonsmokers. Furthermore cigarette smoke condensate increasres SCE in both Chinese hamster chromosomes and human lymphocytes in vitro(DeRaat, 1979; Hopkins and Evans, 1979).

The objective for the present study has been to obtain information regarding the effect of smoking on sister chromatid exchanges and chromosome aberrations in blood leukocytes in chronic and heavy cigarette smokers in order to settle previous

discrepant findings. Also this study was designed to see whether expusure of human leukocytes to cigarette smoke condensate and nicotine leads to inhibition of the mitosis, increase of SCE rate and chromosome aberrations. In this study, blood spectmens from 13 cigarette smokers and 10 healthy nonsmokers were examined for

chromosome aberrations and SCE. The 13 smokers were aged from 21 to 56. They had smoker at least one pack of cigarettes a day for 2 to 38 years. Nicotine was obtained from BDH Chemicals Ltd, Poole, England and dissolved in Hanks solution to give final contcentration of 10,20,30,40,50ug/ml. Smoke condensate was prepared by smoking high tar contain nonfilter cigarettes through a cigarette filter and dissolved in CMSO(50mg/0.1ml) and further diluted with Hanks solution to give a final concentration of 0.25, 0.5,1.0,1.5,2.0 mg/ml. Both nicotine and CSC were treated for 18 hours in a leukocyte cultures prepared one from smoker and one nonsmoker. The slides for mitotic index and chromosome aberrations were prepraed by air-drying technique of Moorhead et al(1960) and stained with Giemsa. The slides for the SCE were made by Fluorescense plus Giemsa method of Perry and Wolff(1974).

The results are summarized as follows:

1) Eompared with nonsmokers, the frequencies of SCE were higher in smokers.

2) In SCE rates there was no difference between ages, duration of smoke and sex among smokers.

3) Frequencies of SCE were increased according to the number of cigarettes smoled per day.

4) In both nicotine and CSC treated leukocytes, there were decressed mitotic indices when concentration of chemicals was increased.

5) There were increased chromosome aberrations and SCE in CSC treated leukocytes but there were no chromosome aberrations and SCE in CSC treated leukocytes but there were no chromosome aberrations or SCE found in nicotine treated leukocytes.

In conclusion, this study showed an increase in chromosomal aberrations and SCE among smokers depending on the amount of cigarettes smoked per day. Age, sex and duration of smoking did not effect the SCE rates. In vitro study, nicotine produced

inhibition of mitosis and increased mutagenic activity were observed with cigeratte smoke condensate only.