• Toxicological Research
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• 제5권2호
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• pp.151-166
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• 1989

This study was carried out to investigate the effect of red ginseng extract on development of pepsinogen 1 decrased pyloric glands in experimental stomach carcinogenesis in Sprague-Dawley male rats. Sequential quantitative analyses (by ABC immunohistochemical staining) were made of pepsinogen 1 decreased pyloric glands (PDPG) after treating rats first with a single dose (160 mg/kg) N-methyl-N'-nitrosoguanidine (MNNG) and then with N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) (100ug/ml of drinking water) as a second gastric carcinogen (or promoter).

• 대한바이러스학회지
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• 제27권2호
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• pp.257-260
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• 1997

Adenoviruses are icosahedral virions containing double-stranded linea DNA. They are 70 nm to 90 nm in diameter and capsid is composed of 252 capsomeres. Several members of this group, including types commonly associated with respiratory disease in man, are capable of producing malignant tumors in young hamsters and a few types have been shown to be oncogenic in young rat. Previous report involving effect of caffein on transformation induced by Adenovirus type 12 [9] has been carried out. The present report represents a continuation of previous study. To obtain evidence concerning the effect of MNNG (N-methyl-N'-nitro-N-nitroguanidine) on transformation, investigation of adenovirus type 12 of this group was undertaken. For practical consideration it was desirable to investigate the effect of MNNG on the adenovirus type 12 induced transformation in L cell. Results were as following 1. Adeno virus type 12 induced transformation was enhanced in the presence of MNNG. 2. Yields of adeno type 12 virus in L cell were slightly inhibited by treatment of MNNG.

• 대한의생명과학회지
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• 제23권1호
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• pp.30-33
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• 2017

N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) is a carcinogen made of modified guanine on which alkyl group is added on 6th oxygen. It has been used for inducing different types of cancers experimentally in vivo and in vitro. Stomach cancer might be the best well established particular cancer induced with MNNG. Comparative analysis of gene expression between normal stomach cell and MNNG-treated stomach cell could give much information to understand cancer formation in stomach. To this end, normal human stomach cells HS738 were treated with DMSO or MNNG. Genetic comparison was conducted with purified RNA from the treated cells for 6 hours or 24 hours. Total 13 genes were selected based on their high induction folds and comprehensible function to cancer formation. Some of the genes were cancer-promoting whereas the others were anti-cancer genes. These results could give important information of genetic changes in stomach cells during MNNG-induced stomach cancer formation.

• BMB Reports
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• 제28권5호
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• pp.392-397
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• 1995

The effect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on the intracellular $Ca^{2+}$ level was studied in NIH3T3 fibroblast cells. A reduction of the intracellular $Ca^{2+}$ level was observed after exposure to 300 ${\mu}m$ MNNG. However, the intracellular level of $IP_3$, a well-known regulator of $Ca^{2+}$ release from internal storage, was not changed by MNNG treatment. Instead, a reduction of the intracellular NAD level was observed. NAD as well as $IP_3$ stimulated intracellular $Ca^{2+}$ release from permeabilized cells. The treatment of 3-aminobenzamide, which inhibited the MNNG-induced reduction of the NAD level, also prevented the MNNG-induced decrease of the $Ca^{2+}$ level. Our data suggest that MNNG reduces the intracellular $Ca^{2+}$ level by NAD depletion in NIH3T3 cells.

• 생명과학회지
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• 제19권1호
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• pp.1-8
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• 2009

본 연구에서는 monofunctional alkylating agent인 N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) 에 의한 인체 백혈병 U937 세포의 증식억제에 관한 기전 확인하였다. MNNG에 의한 U937 세포의 증식억제는 세포주기 G2/M arrest 및 apoptosis 유방과 연관이 있었으며, MNNG 는 G2/M기 조절에 관여하는 주요 cyclin 및 Cdk들의 발현 수준에는 큰 영향이 없었으나 cyclin B1 및 Cdk2-associated kinase의 활성을 매우 저하시켰다. MNNG 처리로 Cdk inhibit p2l(WAF1/CIP1)이 전사 및 번역 수준에서 발연이 증가되었으며, p21 promoter 의 활성도 증가되었다. p21 promoter deletion constructs을 이용한 연구에서 MNNG의 responsive element 부위는 전사 개시 부위 113-61 부근임을 확인하였다. 이 결과들은 MNNG에 의한 cyclin/Cdk 복합체의 kinase 활성 저하가 p53 비의존적인 p21의 활성 증가에 기인한 것임을 보여주는 것이며, 이는 MNNG의 암세포에서의 항암기전을 이해하는 귀중한 자료로서 제공될 것으로 기대된다.

• 한국어병학회지
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• 제18권3호
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• pp.247-258
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• 2005

이매패류의 각종 화학적 유해인자에 대한 반응특성을 이해하기 위한 연구의 일환으로 화학적 오염물질의 하나인 N-methyl-N-nitro-N-nitrosoguanidine (MNNG)을 바지락에 개체당 1.0 mg씩 단회 주사한 후 240시간 동안 조직손상의 과정을 경시적으로 추적하였다. MNNG에 의하여 조직변화를 보인 곳은 위, 중장 및 후장, 소화맹낭, 생식소로 한정되어 있었다. MNNG를 주사한 후 가장 먼저 변성변화를 보인 조직은 중장상피였으며, 주사 후 12시간째부터 조직학적 변화를 인정할 수 있었다. 소화관 상피 내에는 혈구 (hemocyte)를 포함한 단핵성 괴사세포가 상피에 대량으로 침윤하는 동시에 부분적이거나 완전한 상피파괴 소견이 실험종료까지 확인되었다. 가장 마지막으로 조직학적 변화를 보인 장기는 생식소였으며, 주사 후 144시간째부터 생식상피의 괴사성 탈락을 인정할 수 있었다. 또한, 혈구에 특이적으로 결합하는 Ricinus communis (RCA-Ⅰ) lectin으로 조직화학염색을 실시한 결과에서 이들 소화상피에 침윤하는 세포가 대부분 혈구임이 강하게 시사되었다. 이상의 결과에서, 소화기계가 MNNG의 비경구적 노출에 의해 손상받기 쉬우며, MNNG에 의해 야기되는 소화상피 파괴에는 혈구가 깊이 관여하는 것으로 사료되었다.

• 한국환경성돌연변이발암원학회지
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• 제9권2호
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• pp.63-72
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• 1989

본 연구는 N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) 를 처리한 CHO-K1세포에서 DNA 복제억제와 그 회복과정의 분자론적 기작을 규명할 목적으로 방사선 이중표지에 의한 DNA합성율의 측정, 알카리 자당농도구배 초원심분리법에 의한 DNA 분자량과 후복제 회복율을 측정하여 다음과 같은 결과를 얻었다. DNA 합성율은 2nM 이하의 낮은 농도의 MNNG 처리군에서는 급격히 감소하였으나, 5nM 이상의 농도에서는 그 감소양상이 둔화되었다. 억제되었던 DNA 합성율은 시간경과에 따라 회복되어 처리 후 4시간 째에는 대조군 수준 또는 그 이상으로 회복되었다. MNNG 처리 후 DNA 분자 크기의 분포와 새로 합성된 DNA 분자의 생장양상을 알카리 자당농도구배 초원심분리법으로 조사한 결과 MNNG 처리 후 시간 경과에 따라 새로합성된 DNA 분자들의 크기분포는 1*107 달톤 이하의 DNA 분자들의 합성양이 특이하게 증가하였다가 감소함을 보였다.

• Archives of Pharmacal Research
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• 제16권3호
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• pp.196-204
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• 1993

Flavonol derivatives were tested for their anticlastogenic effect against induction of micronuclei by n-methyl-n'-nitor-n-nitorsoguanidine(MNNG), and against induction of chromosome aberration by bleomycin or MNNG.belomycin. For micronudeus assay, each flavonol derivative (0, 0.001, 0.01, 0.1, 1, 10 and 100 mg/kg) was administered orally twice with 24 h interval, together with intraperitioneally administered MNNG(150 mg/kg). The result showed that msot flavonol derivatives tested were effective in suppresing the frequencies of micronude induced by MNNG. For chromosome aberration assy, each flavonol derivative (0, 0.1, 1, 10m and 100 mg/kg)was administered to mice orally in vivo, and then mice were sacrificed and spleen lymphocyte cultures were made. Bleomycin $(3\;\mu$g/ml) was treated to the mouse spleen hymphocyte cultures at 24 h after con A initiation. There wre nomarked decrease tendencies in chromosome aberration unless all doses of galangin and some doses of several flavonol derivatives tested. In the another experiment, we have evaluated the effect of flavonol derivatives on the enhancement of bleomycin-induced chromsome aberration by MNNG. Most of flavonol derivtives reduced the incidence of chromosome aberration induced by in vitro treatment of bleomycin followed by in vivo treatment of MNNG. Galangin particulary showed a dose-dependent decrease tendency. Other flavonol derivative showed slightly suggest that most of flavonol derivatives may be capable of protecting the inhibition of suggest that most of flavonol derivatives may be capable of protecting the inhibition of DNA-repair by MNNG. Our data indicate clearly that flavonol derivatives can suppress MNNG-induced genotoxicity such as an induction of MNPCEs. Therfore, our results could suggest that flavonol derivtives may be useful as a chemopreventive agent of MNNG.

• 한국환경성돌연변이발암원학회지
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• 제9권1호
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• pp.47-55
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• 1989

Quantitative analyses were made of pepsinogen 1 (Pg 1) decreased pyloric glands after treating male Wistar rats with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and NaCl and then with various test chemicals. Animals received MNNG in drinking water (100ng/ml) and 10% NaCl in diet for 8 weeks (group1), followed by basal diet containing 0.01% capsaicin, 0.5% allyl sulfide, 0.5% indole-3-carbinol and 0.05% germanium until 20 weeks (groups 2-5).

• 약학회지
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• 제37권5호
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• pp.483-489
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• 1993

Bifidobacterium bifidum, one strain of medical preparations being on the market for human intestinal disorder, is very sensitive to rifampicin. If this preparation is taken with rifampicin, its therapeutic effect can't be expected. To develope rifampicin resistant mutants, B. bifidum was treated with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG). All of thirty strains grown on the plates containing 10 $\mu\textrm{g}$/ml rifampicin were over 1, 000 times more resistant to rifampicin than parental strain and they were identified as B. bifidum by fructose-6-phosphoate phosphoketolase test. Three strains out of thirty, which produced almost same amount of organic acid as parental strain, were selected for further studies. They showed identical growth inhibition activity aganist E. coli compared with that of parental strain. And rifampicin was not inactivated.