• YAKHAK HOEJI
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• v.49 no.5
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• pp.380-385
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• 2005

The aim of this study is to investigate the effects of verapamil on the pharmacokinetics of tamoxifen following oral administration of tamoxifen with verapamil to rats. Tamoxifen (10 mg/kg) was administered orally in the presence or absence of verapamil (1, 3 or 6 mg/kg). Compared to the control group (given tamoxifen alone), the presence of verapamil significantly (p<0.05 by 1 mg/kg, p<0.01 by 3 and 6 mg/kg) increased the areas under the plasma concentration-time curve (AUC) and the peak concentrations ($C_{max}$) of tamoxifen. Consequently, the relative bioavailability ($RB\%$) of tamoxifen with verapamil was 1.6-2.1 fold higher than that of the control. But the time to reach peak concentration ($T_{max}$) and the terminal half-life ($t_{1/2}$) of tamoxifen were not altered significantly in the presence of verapamil. The increased AUC and $C_{max}$ of tamox­ifen in the presence of verapamil might be associated with the inhibition by verapamil of the P-glycoprotein and the first­pass metabolizing enzyme CYP3A4 in small intestinal mucosa. The drug interaction should be taken into consideration when tamoxifen is used to the patient with verapamil in the clinical setting.

• Toxicological Research
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• v.20 no.3
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• pp.195-203
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• 2004

4-Tert-Octylphenol (OP) is a surfactant additive widely used in the manufacture of a variety of detergents and plastic products. OP can disrupt endocrine function in humans and animals. This study was carried out to obtain toxicokinetic parameters of OP in male Sprague-Dawley (SD) rats. Male rats were administered with OP by single oral application of 200 mg/kg body weight. Blood, urine and tissues samples were taken at several time intervals after administration. Analysis of samples for OP was performed by column-switching high performance liquid chromatography (HPLC). In addition, we exam-ined tissue distribution and accumulation of OP after single oral application of 50, 100, and 200 mg/kg, single intravenous injection of 1, 5 and 10 mg/kg or daily application of 50 mg/kg for 14 consecutive days. After single oral administration of 200 mg/kg, Cmax of 213 $\pm$ 123 ng/ml was reached within the first 1.3 hr (Tmax) in the plasma. AUC was calculated for 1,333$\pm$484 ngㆍhr/ml. The final elimination half-life of plasma was longer than that of urine, but urinary clearance was lower than oral. A very small fraction of OP (Fe < 0.0017%) was excreted in urine within 24 hr. These results indicated that the major excretion route of OP was not urine. The mean maximal tissue distribution of OP was obserbed at 6 hr after treatment and slowly decreased time-dependently. High OP concentrations were detected in fat at 24 hr. The OP in fat was slowly released with longer elimination half-life and lower clearance than that of other tissues. OP was not accumulated in the liver following single oral application but 14-day oral treatments resulted in two-fold accumulation. It was probably due to the saturation of detoxification pathways. On the other hand, the mRNA expression of cytochrome P450 isoforms except CYP2C11 was not affected by OP at any dose. The expression of CYP2C11 mRNA decreased in a dose-dependent manner. This result suggests that OP changes expression of the male-specific cytochrome P450 isoforms in rat liver, and these changes are closely related to the toxic and estrogenic effect of OP.

• The Journal of Internal Korean Medicine
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• v.32 no.2
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• pp.243-258
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• 2011

Objectives : This study investigated the hypolipidemic and antioxidant effects of Curcuma radix using a rat model induced by poloxamer 407 injection. Methods : Serum lipid parameters and oxidative stress-associated biomarkers were determined. Additionally, hepatic cholesterol and triglyceride as well as lipid metabolism-associated gene expressions were observed in hepatic tissue. Results : 1. Curcuma radix ameliorated elevation of serum cholesterol, triglyceride, LDL-cholesterol, MDA, hepatic cholesterol level, and reduction of serum TAC, SOD, GSH, GSH-reductase level. 2. Curcuma radix augmented up-regulated ACAT gene expression. 3. Curcuma radix almost completely ameliorated down-regulated CYP-7A1 but up-regulated HMG-CoA gene expression. Conclusions : The hypolipidemic and antioxidant properties of Curcuma radix were evidenced. This study provides a scientific basis for the clinical application of Curcuma radix and development of hypolipidemics using this herb in the future.

• Korean Journal of Clinical Pharmacy
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• v.19 no.1
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• pp.32-36
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• 2009

The aim of this study was to investigate the effect of simvastatin on the pharmacokinetics of nicardipine in rats. Pharmacokinetic parameters of nicardipine were determined after an oral administration of nicardipine (12 mg/kg) to rats coadministered with simvastatin (0.3 and 1.0 mg/kg). Compared with the control (given nicardipine alone), coadministration of simvastatin (1.0 mg/kg) significantly (p<0.05) increased the area under the plasma concentration (AUC) and peak plasma concentration ($C_{max}$) of nicardipine. The relative bioavailability (RB%) of nicardipine increased from 1.19- to 1.48-fold. However there were no significant changes in $t_{max}$, and $t_{1/2}$ of nicardipine. The enhanced oral bioavailability of nicardipine might be due to an inbition of cytochrom P450 3A mediated-metabolism of nicardipine in the intestine and in the liver by simvastatin. Based on these results, the concurrent use of simvastatin significantly enhanced the oral exposure of nicardipine in rats. The dosage regimen of nicardipine should be taken into consideration for potential drug interaction when combined with simvastatin in clinics.

• Journal of Society of Preventive Korean Medicine
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• v.15 no.1
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• pp.1-16
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• 2011

Objectives : The mechanisms for korean traditional medicine-drug interaction has not been well reviewed in spite that the chance for co-administration with western drugs or diet supplements has been increased. Especially, it is well known that various cytochrome P450s play a major role in drug-drug interaction. Of course, Korean traditional medicines is not excluded in a view of metabolism or biotransformation by cytochrome P450. This article was focused on reviewing the possible roles of cytochrome P450 in Korean traditional medicine-drug interaction, Also, the directions for further studies were suggested in terms of Korean traditional medicine-drug interaction. Methods : New studies for korean traditional medicine-drug interaction were reviewed and summarized in terms of cytochrome P450 activities by various Korean traditional medicines and western drugs. Results and Conclusions : Even if a few studies related to Korean traditional medicine-drug interactions was carried out, almost no studies for Korean traditional medicine-drug interactions has been found in a view of cytochrome P450. It was suggested that Korean traditional medicines and their decoction should be analyzed that how they effects on cytochrome P450, expecially CYP 1, 2, 3 families and how they interact with western drugs.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.16 no.3
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• pp.117-122
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• 2016

제1형 고셔병(Gaucher disease type 1)은 리소좀 효소인 산성 ${\beta}$-글루코시다아제(acid ${\beta}-glucosidase$)의 결핍으로 인한 리소솜 축적 질환이다. 효소 활성도가 감소되어 기질이 축적되어, 간비종대, 빈혈, 혈소판감소증 및 골질환을 포함한 전신 증상이 발생한다. 재조합 효소 단백을 정맥 주입하는 효소 대체요법(Enzyme replacement therapy)는 지난 20년 넘게 고셔병의 표준 치료법이었다. 그러나 성공적인 효소 대체요법에도 불구하고, 심각한 폐증상과 골격 증상 등 고셔병 치료에 여전히 해결되지 않는 문제들이 남아 있다. 기질 감소 치료(Substrate reduction therapy)는 기질의 생합성을 억제하여 축적을 감소시킨다. 최근 새로운 경구용 기질감소 치료제인 엘리글루스타트(eliglustat)가 적합한 CYP2D6 대사 표현형을 가진 고셔병 성인 환자를 위한 1차 치료제로 미국과 유럽에서 승인되었다. 엘리글루스타트가 아직 한국에서는 쓰이지 않고 있지만, 본 종설에서는 문헌 검토를 통해 고셔병의 새로운 치료로서의 효소 대체요법을 소개하고자 한다. 아직 확고한 결론을 도출하기에는 연구 결과가 제한적이기는 하지만, 현재까지의 데이터에 따르면 엘리글루스타트는 임상 효능에 있어서 효소 보충 요법에 비열등성을 보인다. 장기 결과에 대한 추가 연구가 필요하지만, 엘리글루스타트의 승인은 해당 1형 고셔병 성인 환자들에게 경구 치료제라는 새로운 선택을 가능하게 하였다. 향후 국내에서 엘리글루스타트가 처방 가능해 지면, 각 환자 마다 철저한 평가를 통해 치료법을 선택할 수 있도록 해야 할 것이다. 나아가, 국내 1형 고셔병 환자들을 위해 엘리글루스타트의 사용에 관한 임상적 지침 또한 조만간 개발될 필요가 있다.

• Journal of Pharmaceutical Investigation
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• v.36 no.3
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• pp.157-160
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• 2006

This study investigated the effect of clarithromycin on the pharmacokinetics of ambroxol in rats. The pharmacokinetic parameters of ambroxol in rats were determined after the oral administration of ambroxol (12 mg/kg) in the presence or absence of clarithromycin (5 or 10 mg/kg). Compared with the control (given ambroxol alone), coadministration of clarithromycin significantly (p<0.05 at 5 mg/kg; p<0.01 at 10 mg/kg) increased the area under the plasma concentration-time curve (AUC), peak plasma concentrations $(C_{max})$ and absorption rate constant $(K_a)$ of ambroxol. Clarithromycin increased the AUC of ambroxol in a dose dependent manner within the dose range of 5 to 10 mg/kg. The absolute bioavailability (AB%) of ambroxol in the presence of clarithromycin was significantly higher than that of the control (p<0.05 at 5 mg/kg; p<0.01 at 10 mg/kg), and the relative bioavailability (RB%) of ambroxol with clarithromycin was increased by 1.32-to 1.71-fold. However, there were no significant changes in time to reach peak concentration $(T_{max})$ and terminal half-life $(T_{1/2})$ of ambroxol in the presence of clarithromycin. Coadministration of clarithromycin enhanced the bioavailability of ambroxol, which may be due to the inhibition of intestinal and hepatic metabolism of ambroxol by CYP 3A4. Further studies for the potential drug interaction are necessary since ambroxol is often administrated concomitantly with clarithromycin in humans.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.2
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• pp.72-76
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• 2015

$17{\alpha}$-hydroxylase and 17,20-lyase are enzymes encoded by the CYP17A1 gene and are required for the synthesis of sex steroids and cortisol. In $17{\alpha}$-hydroxylase deficiency, there are low blood levels of estrogens, androgens, and cortisol, and resultant compensatory increases in adrenocorticotrophic hormone that stimulate the production of 11-deoxycorticosterone and corticosterone. In turn, the excessive levels of mineralocorticoids lead to volume expansion and hypertension. Females with $17{\alpha}$-hydroxylase deficiency are characterized by primary amenorrhea and delayed puberty, with accompanying hypertension. Affected males usually have female external genitalia, a blind vagina, and intra-abdominal testes. The treatment of this disorder is centered on glucocorticoid and sex steroid replacement. In patients with $17{\alpha}$-hydroxylase deficiency who are being raised as females, estrogen should be supplemented, while genetically female patients with a uterus should also receive progesterone supplementation. Here, we report a case of a 21-year-old female with $17{\alpha}$-hydroxylase deficiency who had received inadequate treatment for a prolonged period of time. We also include a brief review of the recent literature on this disorder.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.178-182
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• 1998

Previously, we showed that acetone enhanced aryl hydrocarbon hydroxylase (AHH) activity in only 3-methylcholanthrene (MC)- or $\beta$-naphtoflavone (BNF)-inducible microsomes of rat liver. In the present study, the possible mechanism underlying acetone action on AHH was investigated in the liver microsomes from MC-pretreated rats. Other n-alkylketones except acetone did not increase AHH activity, which rather decreased significantly with the length of alkyl side chain. Acetone had no effect on the activity of NADPH-cytochrome P450 reductase or inhibited the formation of 3-OH benzo(a)pyrene (B(a)P) in nonenzymatic model ascorbic acid system. However, in cumene hydroperoxide (CuOOH)-supported B(a)P hydroxylation, acetone enhanced its velocity remarkably by 30% at the optimal concentration (30 $\mu$M CuOOH and 1.0% acetone). From these results, we conclude that acetone may facilitate the formation of an activated oxygen species or the insertion of oxygen into B(a)P molecule in CYP1A rich microsomes.

• YAKHAK HOEJI
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• v.54 no.6
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• pp.522-528
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• 2010

This study was designed to examine the effect of estrogen deficiency on the metabolism of ethanol in ovariectomized rats. Female rats were assigned to an ovariectomy (OVX) and a sham (SHAM) surgery group. Gain body weight was greater in incresed in OVX group and especially uterus weight significantly decrease depending on the concentration of estrogen after 3 month of ovariectomy. Ethanol at the tolerative dose (6 g/kg) was injected to rats by oral administration to measure the concentration of ethanol in blood. The area under the blood concentration time curve (AUC) was significantly lower in OVX group than SHAM group. The significant decrease in AUC in OVX group indicates that the estrogen deficiency leads to changes of the factors related to ethanol metabolism. Activity of hepatic alcohol dehydrogenase was not significantly influenced by the ovariectomy and also the ethanol elimination rate in vivo was not different. Cytochrome P450 isozymes did not show any changes except CYP 1A1 and 2E1. Level of hepatic glutathione in OVX group was higher after treatment of ethanol. Therefore the reduction of AUC appears not to be directly associated with the difference of ethanol metabolizing enzyme, but to be related with the physical factors like body weight.