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Xia JS, Guo DL, Zhang Y, Zhou ZN, Zeng FD, Hu CJ. Inhibitory effects of dauricine on potassium currents in guinea pig ventricular myocytes. Acta Pharmacol Sin 2000; 21:60-4. [PMID: 11263249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
AIM To study the effects of dauricine(Dau) on the rapidly activating component (IKr), the slowly activating component (IKs) of the delayed rectifier potassium current, and the inward rectifier potassium current (IKl) in guinea pig ventricular myocytes. METHODS Single myocytes were dissociated by enzymatic dissociation method. The currents were recorded with the whole-cell configuration of the patch-clamp technique. RESULTS (1) Dau 1, 3, 10, 30, and 100 mumol.L-1 blocked IKr and tail current (IKr-tail) in a concentration-dependent manner. The IC50 for block of IKr-tail was 16 (95% confidence limits: 13-22) mumol.L-1. The time constant of IKr-tail deactivation was (140 +/- 38) ms in the control and (130 +/- 26) ms in the presence of Dau 30 mumol.L-1 (n = 6 cells from 3 animals, P > 0.05). (2) Dau 1-100 mumol.L-1 produced concentration-dependent blocks of IKs and tail current (IKs-tail). The IC50 value for block of IKs-tail was 33 (95% confidence limits: 24-46) mumol.L-1. The time constant of IKs-tail deactivation was (92 +/- 18) ms in the control and (84 +/- 16) ms in the presence of Dau 30 mumol.L-1 (n = 8 cells from 4 animals, P > 0.05). (3) Addition of Dau 30 mumol.L-1 induced block of IKs and IKs-tail (n = 7 cells from 3 animals). The degree of block of IKs and IKs-tail depended on test potentials, increasing with more positive depolarizations. (4) Dau 20 mumol.L-1 blocked mainly inward component of IKl and reduced the reversal potential from -72 mV (control) to -78 mV (n = 6 cells from 3 animals). CONCLUSION (1) Dau inhibited IKs, but not the process of IKs deactivation. (2) Dau blocked IKr, but not the process of deactivation. (3) Dau had a blocking effect on IKl.
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Lu CS, Hu CJ, Yu Y, Meng QJ. The inclusion compounds of beta-cyclodextrin with 4-substituted benzoic acid and benzaldehyde drugs studied by proton nuclear magnetic resonance spectroscopy. Chem Pharm Bull (Tokyo) 2000; 48:56-9. [PMID: 10705476 DOI: 10.1248/cpb.48.56] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Inclusion compounds of some 4-substituted benzoic acid and benzaldehyde drugs with beta-cyclodextrin were prepared and characterized by IR spectroscopy, powder X-ray diffraction, thermogravimetry, and 1H-NMR spectroscopy. The thermal stability and chemical stability of these drugs were strikingly improved after inclusion. The effect of inclusion on the chemical-shifts of protons H-3 and H-5 in the NMR spectroscopy is discussed. Using the relative shift theory, the preferred inclusion mode was proposed. The center of the aromatic ring of the drug molecule was considered to be located in the cavity 1.2 A inside from the H-5 plane of beta-cyclodextrin.
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Hu CJ, Kato A, Bowman MC, Kiyotani K, Yoshida T, Moyer SA, Nagai Y, Gupta KC. Role of primary constitutive phosphorylation of Sendai virus P and V proteins in viral replication and pathogenesis. Virology 1999; 263:195-208. [PMID: 10544094 DOI: 10.1006/viro.1999.9953] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Functional analysis of the primary constitutive phosphorylation of Sendai virus P and V proteins was performed using both in vitro and in vivo systems. Sendai virus minigenome transcription and replication in transfected cells were not significantly affected in the presence of primary phosphorylation deficient P protein (S249A, S249D, P250A) as measured by either the luciferase activity or the Northern blot analysis. Similarly, recombinant Sendai viruses lacking the primary phosphorylation in P grew to titers close to the wild-type virus in cell cultures and in the natural host of Sendai virus, the mouse. Mutant viruses showed no altered pathogenesis in mice lungs. Oligomerization of P by binding WT P or mutant P to GST-P (WT) Sepharose beads revealed that the primary phosphorylation was not crucial for P protein oligomerization. Similar to P protein primary phosphorylation, the V protein primary phosphorylation at serine249 was not essential for minigenome transcription and replication, as both WT and mutant V proteins were found equally inhibitory to the minigenome replication. These results show that the primary phosphorylation of P protein has no essential role in Sendai virus transcription, replication, and pathogenesis.
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Chang JG, Yang TY, Liu TC, Lin TP, Hu CJ, Kao MC, Wang NM, Tsai FJ, Peng CT, Tsai CH. Molecular analysis of secretor type alpha(1,2)-fucosyltransferase gene mutations in the Chinese and Thai populations. Transfusion 1999; 39:1013-7. [PMID: 10533829 DOI: 10.1046/j.1537-2995.1999.39091013.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The human Lewis histo-blood group system belongs to a family of structurally related oligosaccharides. The mutations of fucosyltransferase genes alpha(1,2)-fucosyltransferase (FUT2 or Se) and alpha(1,3/1,4)-fucosyltransferase (FUT3 or Le), are responsible for the polymorphism of Lewis blood group phenotypes. However, a population study of the FUT2 mutation in Chinese and Thais has not yet been done, and there is some controversy about the phenotypes of Le(a+b+) and Le(a+b-). STUDY DESIGN AND METHODS One hundred twentyfour Chinese and 70 Thais were phenotyped for Lea and Le(b). DNA samples were studied by polymerase chain reaction and then by a restriction enzyme digestion method to distinguish wild-type and six known mutations. Direct sequencing was done for controls and some uncertain cases. RESULTS A new mutation, C302T mutation, was found in 2 of 136 chromosomes in the Thai population; none were discovered in Chinese. The frequencies of the normal and six mutant alleles among Chinese and Thais, respectively, were as follows: 134 (54.0%) of 248 and 58 (41.4%) of 140 were wild-type (Se); 0 of 248 and 2 of 140 (both 1.4%) had the G428A mutation; 120 (48.4%) of 248 and 75 (53.6%) of 140 had the A385T mutation; 2 (0.81%) of 248 and 0 of 140 had the C571T mutation; and 1 (0.4%) of 248 and 3 (2.2%) of 140 had the G849A mutation. Only 1 Chinese (0.4%) of 248 had the C628T mutation, and none had fusion gene mutation. CONCLUSION The FUT2 genes encoding for the phenotypes Le(a+b+) and Le(a+b-) are the same. The function and character of the mutant enzyme may play an important role in the phenotype. The methods used in this study are clinically applicable in population studies of the FUT2 gene polymorphism to explore relationships among different ethnic groups and correlations between phenotype and genotype.
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Hu CJ, Sung SM, Liu HC, Lee KY, Hsu WC, Wong WK, Lee CC, Tsai CH, Chang JG. No association of alpha-2 macroglobulin gene five-nucleotide deletion with AD in Taiwan Chinese. Neurology 1999; 53:642-3. [PMID: 10449138 DOI: 10.1212/wnl.53.3.642] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The alpha-2 macroglobulin five-nucleotide deletion (A2M-2) allele frequency was not significantly higher in the AD group than the control group (0.062 versus 0.101, p > 0.1). The odds ratio for AD in individuals with the A2M-2 allele was 0.582 (95% CI, 0.25 to 1.40). These results do not support the association between A2M-2 and AD in the Chinese population, although the allele frequency of A2M-2 is lower than that found in the Caucasian population. Therefore, A2M-2 might not be a significant risk factor of AD among Taiwan Chinese.
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Lin SP, Chang JG, Jong YJ, Yang TY, Tsai CH, Wang NM, Li H, Hsieh-Li HM, Hu CJ. Prenatal prediction of spinal muscular atrophy in Chinese. Prenat Diagn 1999; 19:657-61. [PMID: 10419615 DOI: 10.1002/(sici)1097-0223(199907)19:7<657::aid-pd602>3.0.co;2-p] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We used linkage analysis, non-isotope SSCP (single-strand conformation polymorphism) and PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) for prenatal diagnosis of spinal muscular atrophy (SMA). A total of 26 cases from 20 SMA families (16, type 1 and 4) were evaluated. 5 out of 26 fetuses were affected and, following genetic counselling, the parents decided to terminate the pregnancies. Aborted fetal tissues were examined and the diagnosis was confirmed in each case. The 21 unaffected cases were either normals (12 cases) or carriers (9 cases). These children have been followed for six months to two and a half years. No false-negative or false-positive results on prenatal testing were found. We conclude that prenatal diagnosis of SMA is reliable and accurate.
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Hu CJ, Baglia FA, Mills DC, Konkle BA, Walsh PN. Tissue-specific expression of functional platelet factor XI is independent of plasma factor XI expression. Blood 1998; 91:3800-7. [PMID: 9573017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Platelet factor XI is an alternatively spliced product of the factor XI gene expressed specifically within megakaryocytes and platelets as an approximately 1.9-kb mRNA transcript (compared with approximately 2.1 kb in liver cells) lacking exon V. Flow cytometry with an affinity-purified factor XI antibody, with PAC1 antibody (to the GPIIb/IIIa complex on activated platelets), and with S12 antibody (to P-selectin, an alpha-granule membrane protein expressed on the platelet surface during secretion) on platelets activated with ADP, thrombin, thrombin receptor peptide (SFLLRN amide), or collagen at various concentrations exposed platelet factor XI and PAC1 antibody binding in parallel. Unactivated platelets expressed approximately 40% of total platelet factor XI but no PAC1 binding sites. Enhanced membrane exposure of platelet factor XI is independent of alpha-granule secretion, because ADP and collagen exposed platelet factor XI but no S12 binding sites. Platelets from four patients with plasma factor XI deficiency (<0.04 U/mL) had normal constitutive and activation-dependent expression of platelet factor XI. Well-washed platelets from normal and from factor XI-deficient donors incubated with low concentrations of thrombin (0. 05 to 0.1 U/mL) corrected the clotting defect observed with factor XI-deficient plasma. Thus, functionally active platelet factor XI is differentially expressed on platelet membranes in a tissue-specific manner both constitutively and in a concentration-dependent fashion by various agonists in the absence of detectable plasma factor XI.
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Hu CJ, Sung SM, Liu HC, Chang JG. Association of apolipoprotein E genotype and intronic polymorphism of the presenilin-1 gene with Alzheimer's disease in elderly Taiwan Chinese. J Neurol Sci 1998; 157:158-61. [PMID: 9619639 DOI: 10.1016/s0022-510x(98)00052-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We studied the apoliprotein E (apo-E) allele frequencies and intronic polymorphism of the presenilin-1 (PS-1) gene in 55 patients with late-onset Alzheimer's disease (AD) and 93 age- and sex-matched controls. The apoE epsilon4 allele frequency was significantly higher in the AD group than in the control group (0.255 versus 0.070, P<0.0001). The odds ratio for AD in individuals with either one or two epsilon4 alleles was 5.22 (95% confidence interval: 2.32-11.70). The polymorphism within the region composing intron 3' to exon 8 of the PS-1 gene showed a similar distribution between AD patients and controls. This is the first study on the intronic polymorphism of the PS-1 gene in Chinese. Our results support an association between apoE epislon4 and AD in Chinese, but not between the intronic polymorphism of the PS-1 gene and AD. However, the allele frequency of apo-E epsilon4 among Chinese is lower than that among Caucasians. The interaction between apo-E and PS-1 genotypes is still unclear.
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Chang JG, Jong YJ, Wang WP, Wang JC, Hu CJ, Lo MC, Chang CP. Rapid detection of a recombinant hotspot associated with Charcot-Marie-Tooth disease type IA duplication by a PCR-based DNA test. Clin Chem 1998; 44:270-4. [PMID: 9474023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A 1.5-Mb duplication on chromosome 17p11.2-p12 (CMT1A duplication) caused by a misalignment of the CMT1A repeat sequences (CMT1A-REPs) is associated with Charcot-Marie-Tooth disease type 1A (CMT1A). A hotspot of crossover breakpoints located in a 3.2-kb region of the CMT1A-REPs accounts for three-quarters of the rearrangements in CMT1A patients. We developed a PCR-based diagnostic method to detect a recombination hotspot associated with the CMT1A duplication. Thirty-one CMT1A Chinese patients from different families and 50 healthy people over 65 years of age were studied. Twenty-seven of the 31 cases demonstrated the 3.2-kb hotspot crossover, of which there were two subgroups. The type 1 crossover breakpoint was located at the distal CMT1A-REP around the PmeI site, and accounted for 24 of the 27 cases with a 3.2-kb hotspot crossover in CMT1A duplication patients. The type 2 crossover breakpoint was located at the distal CMT1A-REP around the base 3625 region, accounting for 3 of the 27 cases. The results correlated very well with the results of Southern transfer analysis. This study has a potentially important role in the diagnosis of CMT1A disease.
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Guo DL, Zhou ZN, Zeng FD, Hu CJ. Dauricine inhibited L-type calcium current in single cardiomyocyte of guinea pig. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1997; 18:419-21. [PMID: 10322931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
AIM To study the effect of dauricine (Dau) on L-type calcium current in guinea pig ventricular myocytes. METHODS Using whole-cell recording method to record L-type calcium current (ICa) in single ventricular cell of guinea pig. RESULTS Dau 1, 10, and 100 mumol.L-1 markedly reduced ICa by 15.2% +/- 2.2%, 41% +/- 5%, and 82% +/- 8%, respectively. After washing out, ICa partially recovered. Dau inhibited ICa at 3 Hz and 1 Hz to a similar extent, its effect on ICa appeared to be not frequency-dependent. CONCLUSION Dau had a calcium channel blocking effect.
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Guo DL, Zeng FD, Hu CJ. Effects of dauricine, quinidine, and sotalol on action potential duration of papillary muscles in vitro. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1997; 18:348-50. [PMID: 10072920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
AIM To compare the characteristics of dauricine, sotalol, and quinidine on action potential duration (APD). METHODS Using intracellular microelectrode method to record APD in guinea pig papillary muscles. RESULTS Dauricine 20 mumol.L-1 prolonged action potential at 90% repolarization, the percent of APD prolongation were 22 +/- 8, 11 +/- 6, 9 +/- 5, 7 +/- 5, 6 +/- 3, 4.3 +/- 2.8, 4.5 +/- 2.8 at the cycle lengths of 200-2000 ms, dauricine became more effective in lengthening APD at short cycle lengths. The effect of dauricine on prolonging APD exhibited normal use-dependence, whereas quinidine 1 mumol.L-1 and sotalol 10 mumol.L-1 were less effective in lengthening APD at short cycle lengths. The effect of quinidine and sotalol on APD exhibited reverse use-dependence. CONCLUSION [corrected] The effect of dauricine on APD depends on activation frequency.
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Hu CJ, Chan KY, Lin TJ, Hsiao SH, Chang YM, Sung SM. Traumatic brainstem deafness with normal brainstem auditory evoked potentials. Neurology 1997; 48:1448-51. [PMID: 9153490 DOI: 10.1212/wnl.48.5.1448] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A 48-year-old woman became totally deaf after a head injury. Magnetic resonance imaging showed bilateral contusions around the inferior colliculi and the brainstem auditory evoked potentials (BAEP) failed to show any abnormality. This case demonstrates that small, symmetrical, bilateral lesions around the inferior colliculi may cause deafness and may still be associated with a normal BAEP.
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Wang ZX, Zhu JQ, Zeng FD, Hu CJ, Ma YL, Zhong SM. Effects of daurisoline on intracellular Ca2+ activity in myocardium. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1996; 17:248-51. [PMID: 9812749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
AIM To explain the effect of daurisoline (DS) on delayed afterdepolarization (DAD). METHODS Ca(2+)-sensitive microelectrode technic was used to record intracellular Ca2+ activity (alpha Cai) and triggered activity (TA) arising from DAD in myocardium. RESULTS Strophantin G 3 mumol.L-1 yielded an increase in resting myocardial alpha Cai by 0.19 +/- 0.11 mumol.L-1 and transient elevations of alpha Cai by 1.48 +/- 0.55 and 4.96 +/- 1.81 mumol.L-1, respectively during the development of DAD and TA. By pretreatment with DS or verapamil, strophantin G-caused elevations of the alpha Cai in resting and provoked myocardia were eliminated and TA disappeared. DS 50 mumol.L-1 reduced Na(+)-free medium-induced elevation of dog Purkinje fibrous alpha Cai and abolished caffeine-induced increase of dog myocardial alpha Cai. CONCLUSIONS DS inhibited DAD and TA by preventing an increase of alpha Cai via transmembrane Ca2+ entry and Ca2+ release from the reticulum.
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Hu CJ, Ozes ON, Klein SB, Blatt LM, Taylor MW. Comparison of the in vitro host range of recombinant met-interferon-con1, interferon-alpha 2b, and interferon-beta [corrected]. J Interferon Cytokine Res 1995; 15:231-4. [PMID: 7584668 DOI: 10.1089/jir.1995.15.231] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The antiviral activity of human r-metIFN-con1 was compared with that of IFN-alpha 2b and IFN-beta on a number of human, other primate, rodent, feline, and canine cell lines. Although the specific activities of r-metIFN-con1 and IFN-alpha 2b differed 10-fold, the host range was very similar. The host range of IFN-beta differed from that of r-metIFN-con1 and IFN-alpha 2b in that Vero cells were 100-fold better protected by IFN-beta and MDBK protected at a 100-fold less efficiency. In general, there were only minor differences between the host ranges of the three interferons, human and primate cells being better protected than those of other species. However, the tissue of origin of the cell appears to be more important than the species of origin in defining host range [corrected].
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Wang ZX, Zhu JQ, Zeng FD, Hu CJ, Ma YL, Zhong SM. [Measurement of cytoplasmic Ca2+ activity in myocardia with Ca(2+)-sensitive microelectrode]. SHENG LI XUE BAO : [ACTA PHYSIOLOGICA SINICA] 1994; 46:409-14. [PMID: 7973834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The improved neutral ligand ETH1001 Ca(2+)-sensitive microelectrodes (Ca-ISE, tip diameter 0.4-0.8 mumol.L-1) are highly ion selective and sensitive and therefore can be reliably used to measure cytoplasmic Ca2+ activity (alpha iCa) in myocardia. The resting alpha iCa in guinea-pig ventricular trabecula, canine ventricular myocardia and Purkinje fibers were respectively 0.19 +/- 0.01, 0.20 +/- 0.02 and 0.46 +/- 0.07 mumol.L-1. Three mumol.L-1 strophantin G increased the resting and dynamic myocardial alpha iCa by 0.18 +/- 0.02 and 6.69 +/- 2.09 mumol.L-1 respectively, as well as engendered triggered activity (TA). When pretreated with 100 mumol.L-1 dauricine (Dau), strophantin G could no longer increase alpha iCa and TA disappeared. It is suggested thus the applicability of Ca-ISE for measurement of myocardia alpha iCa and TA is obvious.
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Gui YT, Du ZH, Zeng FD, Hu CJ. [First-pass effect of dauricine]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1993; 14:173-5. [PMID: 8352015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The first-pass effect of dauricine (Dau) was compared with that of lidocaine (Lid) by measuring the ventricular fibrillation threshold (VFT) and dauricine plasma concentration in rats or rabbits. After forelimb or mesenteric vein (imv) infusion of Dau at a rate of 1 mg.kg-1 x min-1 in rats, the VFT were 1.64-3.17 or 1.60-2.11 V, respectively. In the case of Lid at 2.5 mg.kg-1 x min-1, the VFT were 1.69-4.79 or 1.67-2.80 V, respectively, after ear vein (iev) or imv infusion of Dau at a rate of 0.5 mg.kg-1 x min-1 in rabbits, the VFT were 6.50-12.14 or 5.81-7.43 V, respectively. Plasma Dau concentration through iev infusion was significantly higher than that through imv route. As the dose of imv infusion increased, AUC of Dau showed a nonlinear increase. The results suggested that Dau showed a considerable first-pass effect, which was dose-dependent.
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Chen BY, Du ZH, Zeng FD, Hu CJ, Ma GE, Hong SH. [Hypotensive effect of dihydrolycorine]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1993; 14:45-9. [PMID: 8503287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Dihydrolycorine-HCL(DL) is a derivative of lycorine, an alkaloid isolated from Lycoris radiata Herb. DL iv 20, 40, and 80 mg.kg-1 lowered the mean arterial pressure in pentobar-bitone-anesthetized normotensive rats, cats, and conscious rats either normotensive or renovascular hypertensive. In pithed rats DL depressed the hypertensive effect of reaction to electric stimulation to the T7-9 segments of spinal cord. DL also depressed the hypertensive effect of phenylephrine. In rabbit aorta ring and rat anococcygeus muscle, DL antagonized the contractile effect of methoxamine, with pA2 values of 5.93 and 6.35, respectively. These results suggest that DL can block alpha 1-adrenoceptors.
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Zhu JQ, Zeng FD, Hu CJ. Protective and anti-arrhythmic effects of dauricine and verapamil on acute myocardial infarction in anesthetized dogs. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1992; 13:249-51. [PMID: 1442108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Dauricine (Dau) 5 mg.kg-1 and verapamil (Ver) 0.15 mg.kg-1 iv followed by infusions of 0.1 and 0.01 mg.kg-1.min-1, respectively, for 30 min, depressed the elevated coronary venous blood LDH and CPK after LAD occlusion. Dau produced antagonistic effects on acute myocardial ischemia-induced ventricular ectopic activities (VE) and ventricular tachycardia (VT). The incidences of VE and VT in Ver group and ventricular fibrillation (VF) in both groups tended to descend. The results suggested that Dau and Ver produced marked protective effects on myocardial infarction and antagonized the acute ischemic arrhythmia.
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Mills DC, Puri R, Hu CJ, Minniti C, Grana G, Freedman MD, Colman RF, Colman RW. Clopidogrel inhibits the binding of ADP analogues to the receptor mediating inhibition of platelet adenylate cyclase. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1992; 12:430-6. [PMID: 1558834 DOI: 10.1161/01.atv.12.4.430] [Citation(s) in RCA: 142] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Clopidogrel, like the homologous thienopyridine derivative ticlopidine, selectively inhibits platelet aggregation induced by ADP. We have previously described two nucleotide-binding sites on platelets related to ADP-mediated platelet responses. The first is a high-affinity binding site for 2-methylthio-ADP (2-MeSADP) that is linked to the inhibition of stimulated adenylate cyclase. The second is the 100-kd exofacial membrane protein aggregin, which is labeled by the reactive ADP analogue 5'-p-fluorosulfonylbenzoyl adenosine (FSBA) that is related to shape change and aggregation. We set out to determine if either of these sites is blocked in vivo by clopidogrel or its active metabolite. Six subjects were given clopidogrel (75 mg/day for 10 days) in a double-blind crossover experiment. All of the subjects developed prolonged bleeding times while taking the drug. The rate of onset of the effect on bleeding time varied among subjects. Platelet aggregation induced by ADP or thrombin was significantly impaired by the drug treatment, but no effect was detected on shape change. The incorporation of [3H]FSBA into aggregin was also unaffected. Inhibition of adenylate cyclase by ADP or by 2-MeSADP was greatly reduced in all subjects, and in the case of 2-MeSADP, there was evidence for a noncompetitive effect. Inhibition of adenylate cyclase by epinephrine was unaffected. In the three subjects for whom binding measurements were made, the number of binding sites for [32P]2-MeSADP was reduced from 534 +/- 44 molecules per platelet during control and placebo periods (11 determinations) to 199 +/- 78 molecules per platelet during drug treatment (three determinations). There was no consistent change in the binding affinity.(ABSTRACT TRUNCATED AT 250 WORDS)
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Puri RN, Hu CJ, Matsueda R, Umeyama H, Colman RW. Aggregation of washed platelets by plasminogen and plasminogen activators is mediated by plasmin and is inhibited by a synthetic peptide disulfide. Thromb Res 1992; 65:533-47. [PMID: 1535463 DOI: 10.1016/0049-3848(92)90204-n] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Plasmin is known to activate platelets. However, it is not clear whether plasminogen activators as used in thrombolytic therapy can aggregate platelets and how this relates to the ability of each activator to convert plasminogen to plasmin. Urokinase (UK) and streptokinase (SK) activated purified plasminogen (2 microM) in a concentration-dependent manner. The rates of aggregation of washed platelets by the above plasminogen activators and plasminogen were similar to the extent of activation of plasminogen to plasmin in the absence of platelets. UK or SK (0.2 microM) and plasminogen (2 microM) aggregated platelets modified by an ADP affinity analog, 5'-p-fluorosulfonylbenzoyladenosine (FSBA), and cleaved aggregin, a putative ADP receptor, in [3H]FSBA-modified platelets. These results suggest that the effect was independent of ADP. In contrast, incubation mixtures containing only plasminogen (2 microM) and single chain tissue plasminogen activator (sc-tPA) (less than or equal to 0.12 microM) neither activated the zymogen to an appreciable extent nor aggregated platelets. But, in the presence of fibrin(ogen) fragments (tPA-stimulator), a mixture of plasminogen and sc-tPA aggregated unmodified and FSBA-modified platelets, and cleaved aggregin. The results imply that platelets, in the presence of t-PA stimulator, potentiate activation of plasminogen to plasmin by t-PA, as previously reported. P1, Phe-Gln-Val-Val-Cys-(NpyS)-Gly-NH2, (NpyS = 3-nitro-2-thiopyridine), a synthetic hexapeptide capable of binding to and inhibiting calpain, has been shown to inhibit platelet aggregation induced by purified plasmin. P1 inhibited platelet aggregation by plasminogen and any of the three plasminogen activators. Our results show that at plasma concentrations of plasminogen and at levels of UK and SK attained after infusion of these agents during thrombolysis, these mixtures can cause maximum aggregation which may contribute to reocclusion and stenosis following infarct therapy. P1 can effectively inhibit platelet aggregation under such conditions.
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Wang RR, Marburger JE, Hu CJ. Tissue-culture-facilitated production of aneupolyhaploid Thinopyrum ponticum and amphidiploid Hordeum violaceum x H. bogdanii and their uses in phylogenetic studies. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1991; 81:151-156. [PMID: 24221196 DOI: 10.1007/bf00215716] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/1990] [Accepted: 07/25/1990] [Indexed: 06/02/2023]
Abstract
An aneupolyhaploid (2n = 36) of the decaploid Thinopyrum ponticum and an amphidiploid (2n = 28) of Hordeum violaceum x Hordeum bogdanii were produced through anther and inflorescence culture, respectively. Meiotic associations in pollen mother cells at metaphase I of these plants were analyzed. The aneupolyhaploid arose by direct embryogenesis from a microspore without passing through a callus phase. The mean pairing frequencies of 2.67 univalents (+) 0.54 rod bivalents (+) 8.85 ring bivalents (+) 2.75 trivalents (+) 0.17 chain quadrivalents (+) 0.56 ring quadrivalents (+) 0.65 pentavalents in the aneupolyhaploid (2n = 36) best fit the 2∶2∶1 model. However, the frequent multivalents (up to five trivalents, or three quadrivalents, or four pentavalents in a cell) indicated that decaploid T. ponticum has five sets of closely related genomes representable by the genome formula J1 J1 J1 J2 J2. Colchicine treatment of inflorescence-derived H. violaceum x H. bogdanii regenerants greatly enhanced the rate of chromosome doubling, and completely doubled regenerants could be isolated. The H. violaceum x H. bogdanii amphidiploid had a mean pairing pattern of 12.53 univalents (+) 5.57 rod bivalents (+) 1.97 ring bivalents (+) 0.07 trivalents (+) 0.03 hexavalents, indicating the presence of desynaptic gene(s) in the original diploiid hybrid. Therefore, the pairing frequency in that diploid hybrid was an under-estimate of chromosome homology between the parental genomes, and additional diploid hybrids are needed to assess the genome homology between H. violaceum and H. bogdanii. These two contrasting experiments demonstrated that tissue culture techniques are useful in altering the ploidy level to produce plant materials suitable for genome analysis and phylogenetic studies.
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Puri RN, Zhou F, Hu CJ, Colman RF, Colman RW. High molecular weight kininogen inhibits thrombin-induced platelet aggregation and cleavage of aggregin by inhibiting binding of thrombin to platelets. Blood 1991; 77:500-7. [PMID: 1846761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In this study we show that high molecular weight kininogen (HK) inhibited alpha-thrombin-induced aggregation of human platelets in a dose-dependent manner with complete inhibition occurring at plasma concentration (0.67 mumol/L) of HK. HK (0.67 mumol/L) also completely inhibited thrombin-induced cleavage of aggregin (Mr = 100 Kd), a surface membrane protein that mediates adenosine diphosphate (ADP)-induced shape change, aggregation, and fibrinogen binding. The inhibition of HK was specific for alpha- and gamma-thrombin-induced platelet aggregation, because HK did not inhibit platelet aggregation induced by ADP, collagen, calcium ionophore (A23187), phorbol myristate acetate (PMA), PMA + A23187, or 9,11-methano derivative of prostaglandin H2 (U46619). These effects were explained by the ability of HK, at physiologic concentration, to completely inhibit binding of 125I-alpha-thrombin to washed platelets. As a result of this action of HK, this plasma protein also completely inhibited thrombin-induced secretion of adenosine triphosphate, blocked intracellular rise in Ca2+ in platelets exposed to alpha- and gamma-thrombin, inhibited thrombin-induced platelet shape change, and blocked the ability of thrombin to antagonize the increase in intracellular cyclic adenosine monophosphate (cAMP) levels induced by iloprost. Because elevation of cAMP is known to inhibit binding of thrombin to platelets, we established that HK did not increase the intracellular concentration of platelet cAMP. Finally, HK did not inhibit enzymatic activity of thrombin. To study the role of HK in the plasma environment, we used gamma-thrombin to avoid fibrin formation by alpha-thrombin. Platelet aggregation induced by gamma-thrombin was also inhibited by HK in a dose-dependent manner. The EC50 (concentration to produce 50% of the maximum rate of aggregation) of gamma-thrombin for washed platelets was 7 nmol/L and increased to 102 nmol/L when platelets were suspended in normal human plasma. The EC50 for platelet aggregation induced by alpha-thrombin in plasma deficient in total kininogen was 40 nmol/L. When supplemented with HK at plasma concentration (0.67 mumol/L), the EC50 increased to 90 nmol/L, a value similar to that for normal human plasma. These results indicate that (1) HK inhibits thrombin-induced platelet aggregation and cleavage of aggregin by inhibiting binding of thrombin to platelets; (2) HK is a specific inhibitor of platelet aggregation induced by alpha- and gamma-thrombin; and (3) HK plays a role in modulating platelet aggregation stimulated by alpha-thrombin in plasma.
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Zhu JQ, Zeng FD, Hu CJ. Effects of dauricine on transmembrane potential of ischemic and non-ischemic Purkinje fibers and ventricular muscles from infarcted canine hearts. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1990; 11:506-9. [PMID: 2130614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Dauricine (Dau) 1-30 mumol/L produced the concentration-dependent depression of APA, Vmax, MDP, and RP, and prolongations of APD90 of Purkinje fibers (PF) and epicardial ventricular muscles (VM) from both infarcted and non-infarcted zones. The ERP was lengthened only in non-ischemic PF and VM, and APD50 in non-ischemic PF, non- and ischemic VM. The prolonging effects of Dau on APD and ERP of ischemic PF were much less than those of non-ischemic ones, and its depressing effect on the Vmax of ischemic VM was markedly greater than that of non-ischemic VM. The results suggest that Dau exerts its anti-arrhythmic effect through further depressing conduction of ischemic zone.
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Zhu JQ, Zeng FD, Hu CJ. Effects of dauricine and lidocaine alone or combined on electrophysiological properties of canine Purkinje fibers. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1990; 11:220-5. [PMID: 2087994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Dauricine (Dau) 1 to 30 mumol/L produced the concentration-dependent depressions in the APA, Vmax, MDP, and prolongations of APD50 and APD90 as well as ERP of the isolated canine cardiac Purkinje fibers (PF). The automaticity and excitation were significantly reduced at concentration of 30 mumol/L. The effects of Dau on all action potential parameters of PF were observed at all stimulation frequencies (60, 75, 100, 150 beats/min). Lidocaine (Lid) markedly shortened APD50 of PF at concentration of 30 mumol/L and also shortened APD90, ERP and significantly depressed APA, Vmax at 100 mumol/L. When perfused in combination with Dau, Lid appreciably shortened APD50 and APD90, and lightly abbreviated ERP prolonged by Dau.
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Puri RN, Zhou FX, Bradford H, Hu CJ, Colman RF, Colman RW. Thrombin-induced platelet aggregation involves an indirect proteolytic cleavage of aggregin by calpain. Arch Biochem Biophys 1989; 271:346-58. [PMID: 2543293 DOI: 10.1016/0003-9861(89)90284-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
5'-p-Fluorosulfonylbenzoyl adenosine (FSBA), a nucleotide analog of ADP, has been shown to inhibit ADP-induced shape change, aggregation and exposure of fibrinogen binding sites concomitant with covalent modification of a single surface membrane polypeptide of Mr 100,000 (aggregin). Since thrombin can aggregate platelets which have been modified by FSBA and are refractory to ADP, we tested the hypothesis that thrombin-induced platelet aggregation might involve cleavage of aggregin. At a low concentration of thrombin (0.05 U/ml), platelet aggregation, exposure of fibrinogen receptors and cleavage of aggregin in FSBA-modified platelets did not occur, indicating ADP dependence. In contrast, incubation of [3H]FSBA-labeled intact platelets with a higher concentration of thrombin (0.2 U/ml) resulted in cleavage of radiolabeled aggregin, aggregation, and exposure of fibrinogen binding sites. Under identical conditions, aggregin in membranes isolated from [3H]FSBA-labeled platelets was not cleaved by thrombin. Thrombin-induced platelet aggregation and cleavage of aggregin were concomitantly inhibited by a mixture of 2-deoxy-D-glucose, D-gluconic acid 1,5-lactone, and antimycin A. These results suggest that thrombin cleaves aggregin indirectly by activating an endogeneous protease. Thrombin is known to elevate intracellular Ca2+ concentration and thereby activates intracellular calcium dependent thiol proteases (calpains). In contrast to serine protease inhibitors, calpain inhibitors including leupeptin, antipain, and ethylene glycol bis(beta-aminoethyl ether) N,N'-tetraacetic acid (chelator of Ca2+) inhibited platelet aggregation and cleavage of aggregin in [3H]FSBA-labeled platelets. Leupeptin, at a concentration of 10-20 microM, used in these experiments, did not inhibit the amidolytic activity of thrombin, thrombin-induced platelet shape change, or the rise in intracellular Ca2+. Purified platelet calpain II caused aggregation of unmodified and FSBA-modified platelets and cleaved aggregin in [3H]FSBA-labeled platelets as well as in isolated membranes. The latter is in marked contrast to the action of thrombin on [3H]FSBA-labeled membranes. Thus, thrombin-induced platelet aggregation may involve intracellular activation of calpain which proteolytically cleaves aggregin thus unmasking latent fibrinogen receptors, a necessary prerequisite for platelet aggregation.
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