• 제목/요약/키워드: cytochrome P450s

검색결과 359건 처리시간 0.032초

흰쥐에 있어서 홍국 첨가 식이가 혈청 지질성분 및 간조직의 유해산소 대사효소활성에 미치는 영향 (Hepatic Oxygen Free Radical Metabolizing Enzyme Activities and Serum Lipid Profile in Rats Fed Diet Supplemented with Monascus Pigment)

  • 유대식;김현희;윤종국
    • 한국식품영양과학회지
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    • 제32권2호
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    • pp.244-249
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    • 2003
  • 홍국 첨가식 이로 성장시킨 흰쥐에 있어서 간조직의 유해산소 기구와 혈청지질 성분의 변동에 어떠한 영향을 미치는지를 검토할 목적으로 Monascus로 제조된 홍국을 사료에 2%, 4% 첨가시켜 1개월 간 사육한 후, 처치하여 다음과 같은 결과를 얻었다. 300g 내외의 흰쥐를 홍국 첨가식 이로 1개월 간 성장시키는 동안 2% 홍국 첨가식이군의 체중증가율은 대조군 및 4% 홍국 첨가식이군보다 다소 낮게 나타나는 경향을 보였으며, 이러한 조건 하에서 간 기능은 2%, 4% 홍국첨가 식이군 모두 별다른 변화를 나타내지 않았다. 유해산소 생성 에 관여하는 cytochrome P450 dependent aniline hydroxylase 활성은 2% 및 4% 홍국 첨가식이군이 대조군에 비해서 각각 32%, 37%의 유의한(p<0.05)감소를 보였으며 홍국 첨가식이 농도를 달리한 실험군 간에 유의한 차이가 나타나지 않았다. 그러나 xanthine oxidase 활성은 2% 및 4% 홍국첨가 식이군이 대조군에 비해서 각각 29%, 36% 증가되었으며 2군간에는 의의있는 차이는 없었다. 유해산소 해독에 관여하는 glutathione-5-transferase와 glutathion peroxidase 활성은 2% 및 4% 홍국 첨가식이군 모두 대조군에 비해서 각각 1.1%, 23%의 유사한 증가를 보였으며, 특히 Catalase의 활성은 2%및 4% 홍국 첨가식이군이 대조군에 비해서 각각 41%, 25%의 유의한 (p<0.05) 증가를 보였다. 그리고 superoxide dismutase의 활성과 간조직 glutathione의 함량은 2% 및 4% 홍국 첨가식이군이 대조군에 비해서 높게 나타나는 경향을 보였으며, 2% 흥국 첨가식이군이 4% 홍국 첨가식이군보다 약간 높게 나타났다. 한편 혈청 중 HDL-cholesterol은 2% 및 4% 홍국 첨가식이군이 대조군에 비해서 16% 및 8%높게 나타나는 반면, LDL-cholesterol은 대조군에 비해서 다같이 약 26% 정도 감소되는 경향을 보였고, triglyceride의 함량 역 시 2% 및 4% 홍국 첨가식이군이 대조군에 비해서 모두 약 25% 정도 감소되는 경향을 보였다. 이때 동맥경화지수는 2$^{\circ}C$ 및 4% 홍국 첨가식이군이 대조군에 비해서 각각 39%, 29%의 유의한(P<0.05) 감소를 보였으며, 2% 홍국 첨가식이군 4% 홍국 첨가식이군보다 감소의 정도가 크게 나타나는 경향을 보였다. 이상 실험결과를 종합해 볼 때 홍국 성분은 oxygen free radical의 일종인 $H_2O$$_2$를 제거하는 효소인 catalase의 활성을 증가시킴으로서 유해산소에 의한 동맥경화증의 발생을 예방시켜 줄 수 있을 것으로 사료되나 이점에 대해서는 추후 계속적인 연구 검토가 행해져야할 것으로 생각된다.

Susceptibility of Lung Cancer with Polymorphisms of CYP1A1, GSTM1, GSTM3, GSTT1 and GSTP1 Genotypes in the Population of Inner Mongolia Region

  • Jiang, Xue-Yan;Chang, Fu-Hou;Bai, Tu-Ya;Lv, Xiao-Li;Wang, Min-Jie;Wang, Guang
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권13호
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    • pp.5207-5214
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    • 2014
  • Background: To study the relationship of susceptibility to lung cancer with the gene polymorphisms of CYP1A1, GSTM1, GSTM3, GSTT1, GSTP1 and smoking status in Han and Mongolian populations of Inner Mongolia, an autonomous region of China. Materials and Methods: PCR-RFLP, allele-specific and multiplex PCR were employed to identify the genotypes of CYP1A1, GSTM1, GSTM3, GSTT1 and GSTP1 in a case-control study of 322 lung cancer patients diagnosed by bronchoscopy and 456 controls free of malignancy. Results: There is a significant difference in genotypic frequency of GSTT1 of healthy Mongolian and Han subjects. A statistically prominent association was found between CYP1A1 Msp1 (vt/vt) (OR=4.055, 95%CI:2.107-7.578, p=0.000), GSTM1 (-) (OR=2.290, 95%CI:1.467-3.573, p=0.000) and lung cancer in Mongolians. Similarly, in the Han population, CYP1A1 Msp1 (vt/vt) (OR=3.194, 95%CI:1.893-5.390, p=0.000) and GSTM1 (-) (OR=1.884, 95%CI:1.284-2.762, p=0.001) carriers also had an elevated risk of lung cancer. The smokers were more susceptible to lung cancer 2.144 fold and 1.631 fold than non-smokers in Mongolian and Han populations, respectively. The smokers who carried with CYP1A1 Msp1 (wt/vt+vt/vt), exon7 (Val/Val+Ile /Val), GSTM1 (-), GSTM3 (AB+BB), and GSTT1 (-) respectively were found all to have a high risk of lung cancer. Conclusions: CYP1A1 Msp1 (vt/vt) and GSTM1 (-) are risk factors of lung cancer in Han and Mongolian population in the Inner Mongolia region. The smokers with CYP1A1 Msp1 (wt/vt+vt/vt), CYP1A1 exon7 (Val/Val+Ile /Val), GSTM1 (-), GSTM3 (AB+BB), and GSTT1 (-) genotypes, respectively, are at elevated risk of lung cancer.

Reoxygenation Stimulates EDRE(s) Release from Endothelial Cells of Rabbit Aorta

  • Suh, Suk-Hyo;Han, Jae-Jin;Park, Sung-Jin;Choi, Jai-Young;Sim, Jae-Hoon;Kim, Young-Chul;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • 제3권4호
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    • pp.393-404
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    • 1999
  • We have reported that hypoxia stimulates EDRF(s) release from endothelial cells and the release may be augmented by previous hypoxia. As a mechanism, it was hypothesized that reoxygenation can stimulate EDRF(s) release from endothelial cells and we tested the hypothesis via bioassay experiment. In the bioassay experiment, rabbit aorta with endothelium was used as EDRF donor vessel and rabbit carotid artery without endothelium as a bioassay test ring. The test ring was contracted by prostaglandin $F_{2a}\;(3{\times}10^{-6}\;M)$ which was added to the solution perfusing through the aorta. Hypoxia was evoked by switching the solution aerated with 95% $O_2/5%\;CO_2$ mixed gas to one aerated with 95% $O_2/5%\;CO_2$ mixed gas. Hypoxia/reoxygenation were interexchanged at intervals of 2 minutes (intermittent hypoxia). In some experiments, endothelial cells were exposed to 10-minute hypoxia (continuous hypoxia) and then exposed to reoxygenation and intermittent hypoxia. In other experiments, the duration of reoxygenation was extended from 2 minutes to 5 minutes. When the donor aorta was exposed to intermittent hypoxia, hypoxia stimulated EDRF(s) release from endothelial cells and the hypoxia-induced EDRF(s) release was augmented by previous hypoxia/reoxygenation. When the donor aorta was exposed to continuous hypoxia, there was no increase of hypoxia-induced EDRF(s) release during hypoxia. But, after the donor aorta was exposed to reoxygenation, hypoxia-induced EDRF(s) release was markedly increased. When the donor aorta was pretreated with nitro-L-arginine $(10^{-5}$ M for 30 minutes), the initial hypoxia-induced EDRF(s) release was almost completely abolished, but the mechanism for EDRF(s) release by the reoxygenation and subsequent hypoxia still remained to be clarified. TEA also blocked incompletely hypoxia-induced and hypoxia/reoxygenation-induced EDRF(s) release. EDRF(s) release by repetitive hypoxia and reoxygenation was completely blocked by the combined treatment with nitro-L-arginine and TEA. Cytochrome P450 blocker, SKF-525A, inhibited the EDRF(s) release reversibly and endothelin antgonists, BQ 123 and BQ 788, had no effect on the release of endothelium-derived vasoactive factors. Superoxide dismutase (SOD) and catalase inhibited the EDRF(s) release from endothelial cells. From these data, it could be concluded that reoxygenation stimulates EDRF(s) release and hypoxia/reoxygenation can release not only NO but also another EDRF from endothelial cells by the production of oxygen free radicals.

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고지방식이 흰쥐에서 산초나무 Butanol 및 Methylene Chloride 분획의 항혈전 및 항염증 작용 (Anti-Thrombogenic and Anti-Inflammatory Effects of Solvent Fractions from Leaves of Zanthoxylum Schinifolium (Sancho Namu) in Rats Fed High Fat Diet)

  • 장현서;이순재;우미희;조성희
    • Journal of Nutrition and Health
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    • 제40권7호
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    • pp.606-615
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    • 2007
  • 본 연구에서는 in vitro에서 검색된 산초나무 잎의 용매분획의 항혈전 및 항염증작용을 in vivo에서 확인하고자 고지방식이를 섭취한 흰쥐에게 n-butanol 분획과 methylene chloride분획을 1일 50, 100, 150 mg을 4주간 경구투여 하였다. 혈장 APTT 및 TT는 정상식이군에 비해 고지방식이군에서 유의적으로 감소되었으며, 고지방식이군에 methylene chloride분획 50 mg 이상 공급군은 유의적으로 증가되어 100 mg 이상 공급군은 정상식이군 수준이었다. 다형핵 백혈구 5#-lipoxygenase 활성과 leukotriene $B_4$ 함량이 정상식이군에 비해 고지방식이군에서 증가되었으며, 5#-lipoxygenase 활성은 두 용매 분획을 100 mg 이상 공급한 군들이 모두 감소하였다. 백혈구의 leukotriene $B_4$ 함량은 n-butanol 분획에 의하여 역시 100 mg 이상 공급으로 감소하였으나 methylene chloride 분획에 의하여는 150 mg 공급군에서만 감소하였다. 간 조직 마이크로솜의 cytochrome $P_{450}$ 함량은 정상식이군에 비해 고지방식이군에서 유의적으로 증가되었으며, 두 용매분획의 투여로 감소하는 경향이었으나 butanol 분획 150mg 투여군에서만 유의적으로 감소하였다. 간 조직 $O_2^-$M의 함량과 $H_2O_2$ 함량도 정상식이군에 비해 고지방식이군에서 증가되었으며, butanol 분획 100 mg 이상투여로 $O_2^-$의 함량이 감소하고 methylene chloride분획 100 mg이상에서 $H_2O_2$ 함량이 감소하였고 두 용매 분획을 150 gm 이상 투여하였을 때는 $O_2^-$$H_2O_2$함량이 모두 감소하였다. 간 조직 GST 활성과 GSH 함량 및 GSG/GSSG 비율은 정상식이군에 비해 고지방식이군에서 감소되었으며, 두 용매 분획 150 mg 투여로 유의적으로 증가되었으나 GSG/GSSG 비율은 100 mg이상 투여로 증가하였다. 결론적으로, 산초나무 잎의 methylene chloride분획은 고지방식이 흰쥐에서 혈행 장애와 염증 반응을 완화시키고, 간 조직에서의 자유라디칼 생성계를 약화시킬 뿐만 아니라, glutathione계의 환원상태를 유지시킴으로서 신체를 보호하는 효과가 있으며 butanol 분획은 항혈전 효과를 제외한 항염증 및 항산화작용에 의한 신체 보호 작용은 기대된다. 이러한 활성을 이용하면 날로 증가되는 지방섭취량에 의한 만성퇴행성질환을 억제하는데 우수한 기능성식품 소재로써 활용할 수 있다고 생각된다.

갈화가 에탄올을 투여한 흰쥐의 지질과산화와 알코올 대사효소의 활성도에 미치는 영향 (Effects of Flower of Pueraria lobata on Lipid Peroxidation and Activities of Alcohol Metabolic Enzymes in Alcohol-treated Rats)

  • 이정숙;김나영;이경희;김갑순;박희준;최종원;김석화
    • 한국식품영양과학회지
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    • 제29권5호
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    • pp.935-942
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    • 2000
  • 갈화(flower of Pueraria lobata) 분획 및 활성 성분의 급여가 아급성 알코올 중독된 흰쥐에서의 해독에 미치는 영향을 연구할 목적으로, 25% alcohol을 6주간 투여하여 아급성 알코올 중독상태를 유발한 흰쥐를 3주 더 사육하면서 혈액중 지질 함량의 변동, 알코올 대사계 효소의 활성을 비교 검퇀 결과는 다음과 같다. 알코올 단독 급여군은 대조군에 비하여 체중이 감소되었으며, 알코올-갈화 tectorigenin 급여군의 체중증가량은 대조군 수준에는 미치지 못하였으나, 알코올 단독 급여군보다는 유의적인 회복을 나타냈다. 알코올 단독 급여군의 총지방, 중성 지방, 인지질 함량이 대조군에 비하여 중가하엿고, 알코올-갈화 tcctorigcnin 급여군과 알코올-갈화 kaikasapomin III 급여군의 총지방, 주성지방 함량은 대조군 수준에는 미치지 못하였으나, 알코올 단독 급여군에 비하여 유의적으로 회복되었다. 알코올 단독 급여군의 total cholesterol, LDL-cholesterol, VLDL-cholesterol 함량, AI는 대조군에 비하여 증가하였고, 알코올-갈화 tectorigcnin, kaikasaponin III 급여군은 대조군 수준에는 미치지 못했으나, 알코올 단독 급여군에 버해 유의적으로 회복되았다. 알코올 단독 급여군의 HDL-cholcsterol의 함량은 대조군에 비하여 감소하던 것이 알코올-갈화 tectorigenin 급여군과 알코올-갈화 kaikasaponin III 급여군에서는 대조군 수준에서는 미치지 못하나, 알코올 단독 급여군에 비하여 증가하였다. 알코올 급여 시 cytochrome P 450, AH와 AD활성은 대조군에 비하여 증가했으나, 알코올-갈화 tectorigenin 급여군과 알코올-갈화 kaikasaponin III 급여군의 경우 알코올 단독 급여군보다 낮게 나타났다. 알코올 급여시 ADH활성이 증가하였으며 알코올-갈화 tectorigenin 급여군과 알코올-갈화 kaikasponin III 급여군은 알코올 단독 급여군보다 높게 나타났다. MEOS의 활성은 알코올 급여 시 대조군에 비하여 중가를 보였고, 알코올-갈화 tectorigenin 급여군에서는 알코올 단독 급여군보다 유의적인 증가를 나타냈다. Catalase의 활성은 각 군간의 유의적인 차이를 볼 수 없었다. ALDH의 활성은 알코올 단독 급여군은 대조군의 활성에 비하여 감소되었으나, 알코올-갈화 tectorigenin 급여군과 알코올-갈화 kaikasaponin III 급여군에서 알코올 단독 급여군보다 유의적인 활성증가를 보였다. 이상의 결과를 종합해 볼 때 갈화로부터 분리된 tectorigenin과 kaikasaponin III는 아급성 알코올 중독된 흰쥐 간의 free radical 생성계 효소를 억제시켜 알코올로 인한 간손상을 회복시키고, 알코올 대사 효소계에 관여하여 해독작용에 영향을 미침으로써 알코올 해독에 도움을 줄 수 있을 것으로 사료된다.

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TCDD로 유발된 Oxidative Stress에 대한 생약재 추출물의 방어 및 해독효과 (Protection and Detoxification Effects of Oriental Herb Extract Mixture on TCDD-Induced Oxidative Stress)

  • 황진국;이경진;양희진;박기문
    • 한국식품영양과학회지
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    • 제37권3호
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    • pp.294-301
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    • 2008
  • 본 연구는 삼백초(aururus chinensis), 포공영(Taraxacum platycarpum), 유근피(Ulmus macrocarpa), 감초(Glycyrrhiza glabra), 흑두(Rhynchosia nulubilis)로부터 제조된 생약재 추출 혼합물이 dioxin 중 중독성이 가장 강하다고 알려진 2,3,7,8-tetrachlorodinenzo-p-dioxin(TCDD)에 의한 산화적 스트레스에 미치는 효과를 실험하였다. 정상적인 간세포주를 TCDD에 노출시킨 후 OHEM을 처리한 결과, TCDD에 의한 세포독성을 감소시켰으며, 간세포주로부터 생성된 lactate dehydrogenase, nitric oxide, cytochrome p450의 생성량 측정 결과로 OHEM이 TCDD로 유발된 간 독성을 해독할 수 있는 것으로 나타났다. 그리고 rat을 이용한 TCDD 급성독성 유발 실험에서는 TCDD 투여에 의해 증가된 AST, ALT, ALP, LDH 및 동맥경화지수가 OHEM의 투여에 의해 유의성 있게 감소하였으며 OHEM의 사전투여에 의한 방어효과가 높은 것으로 측정되었다(p<0.05). 또한 OHEM의 투여가 TCDD에 의해 손상된 간세포 조직의 풍선 병변과 공포화를 감소시켰고, 소장 세포의 조직에서는 융모 조직의 부종을 현저하게 감소시켰다.

Screening of Genetic Polymorphisms of CYP3A4 and CYP3A5 Genes

  • Lee, Jin Sol;Cheong, Hyun Sub;Kim, Lyoung Hyo;Kim, Ji On;Seo, Doo Won;Kim, Young Hoon;Chung, Myeon Woo;Han, Soon Young;Shin, Hyoung Doo
    • The Korean Journal of Physiology and Pharmacology
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    • 제17권6호
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    • pp.479-484
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    • 2013
  • Given the CYP3A4 and CYP3A5's impact on the efficacy of drugs, the genetic backgrounds of individuals and populations are regarded as an important factor to be considered in the prescription of personalized medicine. However, genetic studies with Korean population are relatively scarce compared to those with other populations. In this study, we aimed to identify CYP3A4/5 polymorphisms and compare the genotype distributions among five ethnicities. To identify CYP3A4/5 SNPs, we first performed direct sequencing with 288 DNA samples which consisted of 96 Koreans, 48 European-Americans, 48 African-Americans, 48 Han Chinese, and 48 Japanese. The direct sequencing identified 15 novel SNPs, as well as 42 known polymorphisms. We defined the genotype distributions, and compared the allele frequencies among five ethnicities. The results showed that minor allele frequencies of Korean population were similar with those of the Japanese and Han Chinese populations, whereas there were distinct differences from European-Americans or African-Americans. Among the pharmacogenetic markers, frequencies of $CYP3A4^*1B$ (rs2740574) and $CYP3A5^*3C$ (rs776742) in Asian groups were different from those in other populations. In addition, minor allele frequency of $CYP3A4^*18$ (rs28371759) was the highest in Korean population. Additional in silico analysis predicted that two novel non-synonymous SNPs in CYP3A5 (+27256C>T, P389S and +31546T>G, I488S) could alter protein structure. The frequency distributions of the identified polymorphisms in the present study may contribute to the expansion of pharmacogenetic knowledge.

페니트로치온 도태 Yumenoshima 저항성 집파리에 있어서의 파라치온 저항성 메카니즘 (Mechanisms of Parathion Resistance in a Ethyl Fenitrothion-Selected Yumenoshima III Strain of House Flies)

  • 안용준;박정규
    • 한국응용곤충학회지
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    • 제35권3호
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    • pp.254-259
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    • 1996
  • Yumenoshima III 집파리 계통을 ethyl fenitrothion으로 30세대 도태시킨 EF-30 계통에 있어서의 parathion 저항성 메카니즘을 생화학적으로 조사하였다. 아세틸콜린에스테라제 저해활성은 저항성계통과 감수성 SRS 계통간에 커다란 차이를 보여 이 효소의 감수성 저하가 저항성의 주료 메카니즘으로 작용하고 있음을 알 수 있었다. 양 계통에 있어서의 parathion과 paraoxon의 in vitro 분해활성은 미크로좀 및 수용성 분획과 관련이 있으며, 각각 NADPH와 glutathione을 필요로 하였다. 저항성계통은 감수성계통에 비하여 GSH S-transferase 활성이 높아 이 효소가 저항성 메카니즘에 중요한 역할을 하고 있는 것으로 추정되었다. 저항성계통은 parathion에 대하여 101,487배, ethyl parathion에 대하여 25,914배의 저항성비를 나타내어 parathion이 GSH S-transferase의 기질로 작용하고 있음을 알 수 있었다. 이상의 결과로부터 EF-30 계통에 있어서의 저항성 메카니즘에는 수종의 요인이 관여하여 parathion에 대하여 높은 저항성을 나타냄을 알 수 있었으나, 이들 요인이외에 타 요인의 관여를 배제할 수 없었다.

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Induction of Microsomal Epoxide Hydrolase, rGSTA2, rGSTA3/5, and rGSTM1 by Disulfiram, but not by Diethyldithiocarbamate, a Reduced Form of Disulfiram

  • Kim, Sang-Geon;Kim, Hye-Jung
    • Toxicological Research
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    • 제13권4호
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    • pp.339-347
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    • 1997
  • Disulfiram (DSF) and diethyldithiocarbamate (DDC), a reduced form of DSF, protect the liver against toxicant-induced injury through inhibition of cytochrome P450 2E1. The effect of DSF and DDC on the levels of major hepatic microsomal epoxide hydrolase (mEH) and glutathione S-transferase (GST) expression was comparatively studied, given the view that these enzymes are involved in terminal detoxification events for high energy intermediates of xenobiotics. Treatment of rats with a single dose of DSF (20-200 mg/kg, po) resulted in 2- to 15-fold increases in the mEH mRNA level at 24 hr with the ED$_{50}$ value being noted as 60 mg/kg. The mEH mRNA level was elevated ~15-fold at 24 hr after treatment at the dose of 100 mg/kg, whereas the hepatic mRNA level was rather decreased from the maximum at the dose of 200 mg/kg, indicating that DSF might cause cytotoxicity at the dose. In contrast to the effect of DSF, DDC only minimally elevated the mEH mRNA level at the doses employed. DSF moderately increased the major GST mRNA levels in the liver as a function of dose, resulting in rGSTA2, rGSTA3/5 or rGSTM1 mRNA levels being elevated 3- to 4-fold at 24 hr post-treatment, whereas the rGSTM2 mRNA level was not altered. DDC, however, failed to stimulate the mRNA levels for major GST subunits, indicating that the reduced form of DSF was ineffective in stimulating the GST the expression. The effect of other organosulfides including aldrithiol, 2, 2'-dithiobis(benzothiazole) (DTB), tetramethylthiouram disulfide (TMTD) and allyl disulfide (ADS) on the hepatic mEH and GST mRNA expression was assessed in rats in order to further confirm the increase in the gene expression by other disulfides. Treatment of rats with aldrithiol (100 mg/kg, po) resulted in a 16-fold increase in the mEH mRNA level at 24 hr post-treatment. DTB, TMTD and ADS also caused 5-, 9- and 12-fold increases in the rnRNA level, respectively, as compared to control. Thus, all of the disulfides examined were active in stimulating the mEH gene in the liver. The organosulfides significantly increased the rGSTA2, rGSTA3, rGSTA5 and rGSTM1 mRNA levels at 24 hr after administration. In particular, aldrithiol was very efficient in stimulating the rGSTA and rGSTM genes among the disulfides examined. These results provide evidence that DSF and other sulfides effectively stimulate the mEH and major GST gene expression at early times in the liver and that DDC, a reduced form of DSF, was ineffective in stimulating the expression of the genes, supporting the conclusion that reduced form(s) of organosulfur compound(s) might be less effective in inducing the mEH and GST genes through the antioxidant responsive element(s).

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납(Lead)이 취외분비 기능에 미치는 영향 (Effect of Lead Acetate on Pancreatico-biliary Secretion)

  • 신윤용;김원준
    • 대한약리학회지
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    • 제17권1호
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    • pp.17-25
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    • 1981
  • No evidence has accumulated that lead compound is an essential component for biological function in animals. Lead is absorbed primarily through the epithelial mucosal cells in duodenum and the absorption can be enhanced by the substances which bind lead and increase its solubility. Iron, zinc and calcium ions, however, decrease the absorption of lead without affecting its solubility, probably by competing for shared absorptive receptors in the intestinal mucosa. Therefore, the absorption of lead is increased in iron deficient animals. Lead shows a strong affinity for ligands such as phosphate, cysteinyl and histidyl side chains of proteins, pterins and porphyrins. Hence lead can act on various active sites of enzymes, inhibiting the enzymes which has functional sulfhydryl groups. lead inhibits the activity of ${\delta}$-aminolevulinic acid dehydratase for the biosynthesis of hemoproteins and cytochrome, which catalyzed the synthesis of monopyrrole prophobilinogen from ${\delta}$-aminolevulinic acid. Accordingly lead decrease hepatic cytochrome p-450 content, resulting an inhibition of the activity of demethylase and hydroxylase in liver. Little informations are available on the effect of lead on digestive system although the catastrophic effects of lead intoxication are well documented. The present study was, therefore, attempted to investigate the effect of lead on pancreaticobiliary secretion in rats. Albino rats of both sexes weighing $170{\sim}230g$ were used for this study. The animals were divided into one control and three treated groups, i.e., control (physiologic saline 1.5ml/kg i.p.), lead acetate $(l0{\mu}mole/kg/day\;i.p.)$, $Pb(Ac)_2$ and EDTA$(each\;10{\mu}mole/kg/day\;i.p.)$, $Pb(Ac)_2$ and $FeSO_4(each\;l0{\mu}mole/kg/day\;hp)$. The pancreatico-biliary juice was collected under urethane anesthesia, and activities of amylase and lipase were determined by employing Sumner's and Cherry and Crandall's methods. The summarized results are follows. 1) In the experiment for acute toxicity of lead acetate, 20% of mortality was observed in rat treated with lead acetate as well as inhibition of the activity of amylase in the juice at the 3 rd day of the treatment. 2) No increases in body weight were observed in rats treated with lead acetate, while in control group the significant increases were observed. However, the body weights of animals were increased in the group lead acetate plus EDTA or $FeSO_4$. 3) Lead acetate decreased significantly the volume of pancreatico-biliary juice whereas additional treatment of EDTA and $FeSO_4$ prevented it. 4) Total activity of amylase was markedly reduced due to lead acetate treatment, but no change was showed following additional treatment with EDTA and $FeSO_4$. 5) No changes in the cholate and lipase output were observed in rats treated with lead acetate as compared with that of control rats. 6) Increase in bilirubin output in rats treated with lead acetate was shown on the 2nd and 3rd weeks treatment. 7) In the case of in vitro experiment, lead acetate also markedly inhibited release of amylase from pancreatic fragment. 8) Histologic finding indicated that acini vacuolation was induced in the pancreatic tissue of rat treated with lead acete. From the above results, it might be concluded that lead acetate decreases the volume of pancreatico-biliary secretion and inhibits the amylase activity, by acting directly on pancreatic cells.

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