P-20探针位于DMD基因突变热点区,是DMD基因诊断最常用的多态标记。作者在分析21个DMD家系时,除检测到多态片段Msp I 6.0/3.5kb外,在全部受检者中还发现另一组高频多态位点Msp I 2.2/1.8kb,二组多态联合检出杂合子频率为0.7004,使P-20对...P-20探针位于DMD基因突变热点区,是DMD基因诊断最常用的多态标记。作者在分析21个DMD家系时,除检测到多态片段Msp I 6.0/3.5kb外,在全部受检者中还发现另一组高频多态位点Msp I 2.2/1.8kb,二组多态联合检出杂合子频率为0.7004,使P-20对DMD的RFLP分析能力提高近一倍。根据缺失类型进一步分析了P-20区的基因图谱。展开更多
Using guinea pig andrenal microsomes, we studied the inhibitory effects of 20α-hydroxyprogesterone on steroid hydroxylation reactions catalyzed by cytochromes P-450. When 17α-hydroxyprogesterone was used as a substr...Using guinea pig andrenal microsomes, we studied the inhibitory effects of 20α-hydroxyprogesterone on steroid hydroxylation reactions catalyzed by cytochromes P-450. When 17α-hydroxyprogesterone was used as a substrate, 20α-hydroxyprogesterone functioned as a competitive inhibitor on the C_(17)—C_(20) bond cleavage reaction of P-450_(17α lyase). The inhibition constant, K_i was 1.37 μmol/L. 20α-hydroxyprogesterone also competitively inhibited the convertion of 17α-bydroxyprogesterone to 11-deoxycortisol by the action of P-450_(c21). The value of K_i was 1.73μmol/L. When progesterone was used as a substrate, 20α-hydroxyprogesterone inhibited neither the 21-hydroxylation of P-450_(c21). the C_(17)—C_(20) bond cleavage, nor 17α-hydroxylation of P-450_(17α lyase). Based on the seresults, we can deduce that the production of androstenedione from progesterone by the action of P-450_(17α lyase) proceeds through a successive monooxygenase reaction.展开更多
OBJECTIVE:To investigate the efficacy of Tianma(Rhizoma Gastrodiae)and Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis)on cytochrome P450(CYP450)enzyme activities in rats.METHODS:A cocktail strategy was followed to ...OBJECTIVE:To investigate the efficacy of Tianma(Rhizoma Gastrodiae)and Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis)on cytochrome P450(CYP450)enzyme activities in rats.METHODS:A cocktail strategy was followed to evaluate the influence of Tianma(Rhizoma Gastrodiae)and Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis)on the activities of CYP450 isoforms(CYP1A2,CYP3A4,CYP2E1,CYP2C19,CYP2C9,CYP2D6),which were determined by changes in the pharmacokinetic parameters of six probe drugs,theophylline,dapsone,chlorzoxazone,omeprazole,tolbutamide and dextromethorphan.Study groups included,Control group(CG),Tianma(Rhizoma Gastrodiae)group(TM),Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis)group(GT)and Tianma Gouteng(Gastrodia Uncaria)group(TMGT).RESULTS:No significant differences between Tianma(Rhizoma Gastrodiae)and control groups were found.Compared with the control group,in the Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis)group both the AUC and t1/2 of dapsone and tolbutamide were reduced,whereas the CL(clearance rate)of dapsone and tolbutamide were increased.Compared with the control group,in the Tianma Gouteng group,the AUC and t1/2 of dapsone and tolbutamide were reduced,the CL of dapsone and tolbutamide were increased,and the AUC and t1/2 of chlorzoxazone were increased and the CL of chlorzoxazone was reduced.CONCLUSION:Tianma(Rhizoma Gastrodiae)has no significant effect on the six CYP450 subtypes.The activities of CYP3A4 and CYP2C9 were increased by Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis).The activities of CYP3A4 and CYP2C9 were increased,whereas the activity of CYP32E1 was reduced by combined Tianma(Rhizoma Gastrodiae)and Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis).展开更多
文摘P-20探针位于DMD基因突变热点区,是DMD基因诊断最常用的多态标记。作者在分析21个DMD家系时,除检测到多态片段Msp I 6.0/3.5kb外,在全部受检者中还发现另一组高频多态位点Msp I 2.2/1.8kb,二组多态联合检出杂合子频率为0.7004,使P-20对DMD的RFLP分析能力提高近一倍。根据缺失类型进一步分析了P-20区的基因图谱。
文摘Using guinea pig andrenal microsomes, we studied the inhibitory effects of 20α-hydroxyprogesterone on steroid hydroxylation reactions catalyzed by cytochromes P-450. When 17α-hydroxyprogesterone was used as a substrate, 20α-hydroxyprogesterone functioned as a competitive inhibitor on the C_(17)—C_(20) bond cleavage reaction of P-450_(17α lyase). The inhibition constant, K_i was 1.37 μmol/L. 20α-hydroxyprogesterone also competitively inhibited the convertion of 17α-bydroxyprogesterone to 11-deoxycortisol by the action of P-450_(c21). The value of K_i was 1.73μmol/L. When progesterone was used as a substrate, 20α-hydroxyprogesterone inhibited neither the 21-hydroxylation of P-450_(c21). the C_(17)—C_(20) bond cleavage, nor 17α-hydroxylation of P-450_(17α lyase). Based on the seresults, we can deduce that the production of androstenedione from progesterone by the action of P-450_(17α lyase) proceeds through a successive monooxygenase reaction.
基金Supported by the Science and Technology Department of Sichuan Province[Project Name:Study on the Molecular Pharmacokinetic of Tianma(Rhizoma Gastrodiae)and Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis)in Liver Uptake and Elimination of Upper Hyperactivity of Liver-yang,No.2018FZ0096]and the Fundamental Research Funds for the Central Universities(Study on Pharmacodynamics and in Vivo Process of Chinese Herbal Compound in Treatment of ARDS Caused by Covid-19 Syndrome)。
文摘OBJECTIVE:To investigate the efficacy of Tianma(Rhizoma Gastrodiae)and Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis)on cytochrome P450(CYP450)enzyme activities in rats.METHODS:A cocktail strategy was followed to evaluate the influence of Tianma(Rhizoma Gastrodiae)and Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis)on the activities of CYP450 isoforms(CYP1A2,CYP3A4,CYP2E1,CYP2C19,CYP2C9,CYP2D6),which were determined by changes in the pharmacokinetic parameters of six probe drugs,theophylline,dapsone,chlorzoxazone,omeprazole,tolbutamide and dextromethorphan.Study groups included,Control group(CG),Tianma(Rhizoma Gastrodiae)group(TM),Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis)group(GT)and Tianma Gouteng(Gastrodia Uncaria)group(TMGT).RESULTS:No significant differences between Tianma(Rhizoma Gastrodiae)and control groups were found.Compared with the control group,in the Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis)group both the AUC and t1/2 of dapsone and tolbutamide were reduced,whereas the CL(clearance rate)of dapsone and tolbutamide were increased.Compared with the control group,in the Tianma Gouteng group,the AUC and t1/2 of dapsone and tolbutamide were reduced,the CL of dapsone and tolbutamide were increased,and the AUC and t1/2 of chlorzoxazone were increased and the CL of chlorzoxazone was reduced.CONCLUSION:Tianma(Rhizoma Gastrodiae)has no significant effect on the six CYP450 subtypes.The activities of CYP3A4 and CYP2C9 were increased by Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis).The activities of CYP3A4 and CYP2C9 were increased,whereas the activity of CYP32E1 was reduced by combined Tianma(Rhizoma Gastrodiae)and Gouteng(Ramulus Uncariae Rhynchophyllae cum Uncis).
