항생물질이 배양 백혈구에 미치는 영향에 관한 실험적 연구

Abstract

[한글]

항생제는 Penicillin 유도체, Cephalosporin계, Aminoglycoside계, Tetracycline계와 항암성 항생제계로 광범위하게 분류할 수 있는데 이들 약재들의 살균이나 항암효과외에 인체에서 세포분열과 증식의 억제 혹은 염색채의 이상유발등에 관해서는 이론은 많으나 충분히 추측할 수는 있다.

일반항생제의 작용기전은 세균의 세포막의 합성을 저해하거나 세균내의 단백질합성을 억제하는 것으로 알려져 있고 세균이 항생제에 의해서 돌연변이를 일으키는 보고도 있으나 항생제가 세균에만 작용하며 숙주세포에는 영향을 주지 못하는 지에 관해서는 아직까지 보고된 바가 없다.

항암성 항생제는 대부분 DNA의 base pair와 작용, 핵산합성을 방해함으로서 항암작용을 갖는데 정상세포에서도 이와 같은 작용을 가져 염색체의 이상을 일으키는 연구가 다수 보고되어 있다. 그러나 염색체이상의 양상과 특이성에는 정설이 없는 실정이고 더욱이 세포분열에 미치는 영향에 관해서는 거의 보고된 것이 없기에 이들 항암제들의 서로간의 총괄적인 비교관찰은 기초자료에 도움이 될 수 있으리라 기대된다.

본 실험에서는 근래 많이 사용되고 있는 10종의일반 항생제와 4종의 항암성 항생제의 eukarrocyte에 미치는 영향으로서 세포분열억제 및 염색체 이상을 일으키는 양상을 재래식 방법, G-banding법과 자매분체교환 유발법을 사용하여 다음과 같은 비교관찰 결과를 얻

었다.

1. 항생제 계통에 따라 세포분열억제나 염색체 이상유발에 사용되는 최적의 농도가 달랐으며 항암성 항생제 처리군에서는 일반 항생제보다 분열억제작용이 현저히 강했다.

2. 항암성 항생제 처리후에는 염색체나 염색분체 절단과 염색분체교환등 현저히 높은 이상유발율을 보였으며, 그 중 Adriamycin의 이상유발율이 가장 높았고 Bleomycin이 가장 낮았다. 그러나 일반 항생제 처리후 염색체 이상은 그 빈도나 형태로 보아 대조군과 큰 차이가 없었다.

3. 염색체 이상은 일반적으로 크고 긴 염색체에서 흔히 유발되었으며 18시간과 24시간 처리군에서와 농도가 높은 처리군에서 이상율이 높았다.

4. 항암성 항생제 처리군에서는 저농도에서도 자매분체교환법으로 발견된 이상율이 현저히 증가되었는데 이는 G-banding법으로 발견된 염색체 이상율보다 약10배나 높았고, 일반 항생제에서는 대조군과 비슷 하였다.

[영문]

Since Florey and his co-workers reported in 1941, on the remarkable effectiveness of penicillin, a number of clinically useful antibiotics were found and their potency, antibacterial spectrum, metabolism, and mode of action were studied. The most commonly used antibiotics act by one of the following mechanisms: inhibition of cell wall synthesis, action on cell membranes, inhibition of nucleic acid synthesis (Park and Strominger, 1957: Feingold, 1963)

Although it is known that antibiotics act on cell membranes, inhibit protein and nucleic acid synthesis and have some selective toxicity for microorganisms, they also may be quite toxic and act for host cells. However, there have not been any

reports on the effects of antibiotics on the host cells except for anti-tumor antibiotics. Some highly toxic antibiotics such as actinomycin attack deoxyguanosine level on the DNA molecule. As a consequence, messenger RNA formation is blocked. The drug is highly toxic and is used only experimentally and rarely against some forms of malignancies. The chemotherapeutic approach is aimed at inhibition of nucleic acid synthesis which is essential for the growth of the tumor. but the same approach adversely affects some normal tissue. Anti-tumor antibiotics also produce chromosomal aberrations by reacting with base pair of DNA and consequently inhibit nucleic acid (Cohen and Shaw, 1964; Ostertag and Kersten, 1965; Miles, 1970: Bornstein et al, 1971; Vig, 1971; Massimo et al. 1972: Morad et al, 1973; Promchainant, 1975).

The present investigation is aimed at the study of the inhibition of cell division and cytogenetic effects of 10 different common antibiotics and 4 kinds of anti-tumor antibiotics of human leukocyte not only by classical method but with G-banding technique, find by sister chromatid exchange induction method.

In this study, 0.05mg to 10mg/ml of ampicillin, cloxacillin, carbenicillin, methicillin, cefazolin, and 5 to 100ug/ml of streptomycin, kanamycin, gentamicin, tobramycin, vibramycin, and 0.1 to 10ug/ml of actinomycin D, mitomycin C, adriamycin, and 10 to 50ug/ml of bleomycin were treated to normal male human leukocyte culture for 6, 18, 24 hours. The slides for mitotic index and chrormosome aberrations were prepared by air-drying technique of Moorhead(1960) and stained with Giemsa (Haleco). Trypsin treated G-banding was obtained according to a modification of Seabright (1972) and the slides for the sister chromatid exchanges were made by FPG (Fluorescense Plus Giemsa) plus Hoechst 33258-Light-Giemsa method of Perry and Wolf (1974). The results are summarized as follows:

1. According to kinds of antibiotics within effective concentration, mitotic indeces are decreased arid above ail, mitotic indeces of ansi-tumor antibiotics are decreased significantly.

2. The types of chromosome aberrations are mainly chromatid and chromosome breaks, and chromosome exchanges which are found mostly in the anti-tumor antibiotics.

3. In general, with anti-tumor antibiotics treatment, chromosome aberrations occur nonrandomly in large chromosome groups and the highest chromosome aberration per cell is found in the cells treated 18 hours and 24 hours.

4. The frequencies of sister chromatid exchanges of common antibiotics are similar to the control group but for the anti-tumor antibiotics, there are considerably increased sister chromatid exchanges even with low concentration of drugs.

5. Although the frequencies of sister chromatid exchanges and chromosome aberrations increase parallelly when concentrations are increased, the frequencies of sister chromatid exchanges are approximately 10 times higher than chromosome aberrrations in anti-tumor antibiotics.

In conclusion, it can be assumed that misuse of antibiotics may lead to inhibition of cell divisions or some genetic changes in the normal host cells. Moreover, since with anti-tumor antibiotics, there are cytogenetic changes in normal cells with low dose of drugs, it is necessary to keep in mind that genetic damage may occur in body systems by using the antibiotics for therapy.