351
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Bokemeyer D, Sorokin A, Yan M, Ahn NG, Templeton DJ, Dunn MJ. Induction of mitogen-activated protein kinase phosphatase 1 by the stress-activated protein kinase signaling pathway but not by extracellular signal-regulated kinase in fibroblasts. J Biol Chem 1996; 271:639-42. [PMID: 8557667 DOI: 10.1074/jbc.271.2.639] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The intracellular mechanisms involved in the activation of extracellular signal-regulated kinase (ERK) are relatively well understood. However, the intracellular signaling pathways which regulate the termination of ERK activity remain to be elucidated. Mitogen-activated protein kinase phosphatase 1 (MKP-1) has been shown to dephosphorylate and inactivate ERK in vitro and in vivo. In the present study, we show in NIH3T3 fibroblasts that activation of the stress-activated protein kinase (SAPK) pathway by either specific extracellular stress stimuli or via induction of MEKK, an upstream kinase of SAPK, results in MKP-1 gene expression. In contrast, selective stimulation of the ERK pathway by 12-O-tetradecanoylphorbol-13-acetate or following expression of constitutively active MEK, the upstream dual specificity kinase of ERK did not induce the transcription of MKP-1. Hence, these findings demonstrate the existence of cross-talk between the ERK and SAPK signaling cascades since activation of SAPK induced the expression of MKP-1 that can inactivate ERK. This mechanism may modulate the cellular response to stimuli which employ the SAPK signal transduction pathway.
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352
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Lin Y, Lee LC, Yan M. Generation of dynamic pressure pulses downstream of the bow shock by variations in the interplanetary magnetic field orientation. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/95ja02985] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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353
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Yan M. An empirical study on the impact of marital residence arrangement upon gender preference in reproduction. CHINESE JOURNAL OF POPULATION SCIENCE 1996; 8:133-41. [PMID: 12291965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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354
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Jiang Y, Yan M, Gralla JD. Abortive initiation and first bond formation at an activated adenovirus E4 promoter. J Biol Chem 1995; 270:27332-8. [PMID: 7592996 DOI: 10.1074/jbc.270.45.27332] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Abortive initiation at the adenovirus E4 promoter was studied by following the production of RNA formed from the initiating nucleotides UpA and CTP. Formation of a specific short RNA via a reaction with appropriate alpha-amanitin sensitivity required promoter, activator, and ATP. In the absence of any of these, an alpha-amanitin-resistant reaction led to lower levels of a product of unknown origin. The alpha-amanitin-sensitive reaction required open promoter complexes, as assayed directly by permanganate probing. This reaction was not blocked by the inhibition of polymerase C-terminal domain kinase activity or by the lack of DNA supercoiling. Thus, formation of the initial bond of the mRNA appears to require activator and ATP to open the DNA but not phosphorylation of the polymerase C-terminal domain. In addition, the abortive initiation reaction was strongly suppressed when all elongation substrates were present, suggesting that cycling to produce high amounts of abortive product is strongly disfavored during productive initiation at this promoter.
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355
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Yan M, Song H, Xie N, Zhang L. [Changes of intestinal flora in senile mouse models and the antagonistic activity of the root of Astragalus membraceus (Fisch) Bge]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1995; 20:624-6, inside backcover. [PMID: 8679084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Inhaled by mice, ozone induced stronger free radical reaction in the organism and led to a series of changes similar to senility. In this way the senility mouse models were established to observe the changes of intestinal flora in senile mice. The senile mice were given the root of Astrogolus membraceus decoction orally. The results showed that the imbalance of intestinal flora in these mice was recovered.
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356
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Yan M, Rothberg LJ, Kwock EW, Miller TM. Interchain Excitations in Conjugated Polymers. PHYSICAL REVIEW LETTERS 1995; 75:1992-1995. [PMID: 10059181 DOI: 10.1103/physrevlett.75.1992] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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357
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Yan M, Chen SP, Mitchell TE, Gay DH, Vyas S, Grimes RW. Atomistic studies of energies and structures of (hk0) surfaces in NiO. ACTA ACUST UNITED AC 1995. [DOI: 10.1080/01418619508239586] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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358
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Yan M. [Care of complications of percutaneous plugging of patent arterial duct]. ZHONGHUA HU LI ZA ZHI = CHINESE JOURNAL OF NURSING 1995; 30:365-6. [PMID: 8631085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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359
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Cui D, Yan M, Wong S, Zhang X, Xu D. [Chemical constituents of stems and leaves of Fritillaria ussuriensis Maxim]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1995; 20:298, 320. [PMID: 7492363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Three compounds were isolated from stems and leaves of Fritillaria ussuriensis. They were identified as adenosine, galacitiol and succinic acid.
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360
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Yan M, Gong X, Zhang Y. [Effects of glucocorticoid on PMN adhesion induced by TNF]. ZHONGHUA ZHENG XING SHAO SHANG WAI KE ZA ZHI = ZHONGHUA ZHENG XING SHAO SHANG WAIKF [I.E. WAIKE] ZAZHI = CHINESE JOURNAL OF PLASTIC SURGERY AND BURNS 1995; 11:99-102. [PMID: 7648511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
TNF was used as a stimulating factor to study the effects of glucocorticoid (GC) on polymorphonuclear leucocyte (PMN) adhesion. The results showed that tumor necrosis factor (TNF) could increase the PMN adhesion markedly, and Dex could not inhibit the PMN adhesion induced by TNF, but it had a certain effect of prevention. PMN adhesion was increased prominently when Dex and RU 38486 were given after TNF pretreatment.
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361
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Hou C, Zhang X, Fang Q, Shou T, Zeng L, Yan M, Zhou Y, Hu B, Li P. The analysis of disparity evoked potentials by a new form of static random-dot stereograms. YAN KE XUE BAO = EYE SCIENCE 1995; 11:48-52. [PMID: 8575607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE A new form of static random-dot stereograms free of monocular clues was designed as stimulus to elicit disparity evoked potentials. METHODS Disparity evoked potentials were recorded in 40 stereo-normal subjects. The stimulator was a white-black static random-dot stereograms generated by a computer and had no monocular clues. Every subject was tested in disparity stimulus, zero disparity stimulus, monocular stimulus and wearing prism condition. RESULTS A characteristic wide positive wave at about 250 ms was consistently recorded in disparity stimulus, which may be regarded as evidence of the presence of stereopsis. In contrast, recordings for zero disparity stimulus, monocular vision, stimulus and wearing prism condition all demonstrated a markedly difference from recording for disparity stimulus.
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362
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Yan M, Dai T, Deak JC, Kyriakis JM, Zon LI, Woodgett JR, Templeton DJ. Activation of stress-activated protein kinase by MEKK1 phosphorylation of its activator SEK1. Nature 1994; 372:798-800. [PMID: 7997270 DOI: 10.1038/372798a0] [Citation(s) in RCA: 602] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A kinase distinct from the MEK activator Raf, termed MEK kinase-1 (MEKK), was originally identified by virtue of its homology to kinases involved in yeast mating signal cascades. Like Raf, MEKK is capable of activating MEK in vitro. High-level expression of MEKK in COS-7 cells or using vaccinia virus vectors also activates MEK and MAPK, indicating that MEKK and Raf provide alternative means of activating the MAPK signalling pathway. We have derived NIH3T3 cell sublines that can be induced to express active MEKK. Here we show that induction of MEKK does not result in the activation of MAPK, but instead stimulates the stress-activated protein kinases (SAPKs) which are identical to a Jun amino-terminal kinase. We find that MEKK regulates a new signalling cascade by phosphorylating an SAPK activator, SEK1 which in turn phosphorylates and activates SAPK.
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363
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Antoniadis H, Rothberg LJ, Papadimitrakopoulos F, Yan M, Galvin ME, Abkowitz MA. Enhanced carrier photogeneration by defects in conjugated polymers and its mechanism. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:14911-14915. [PMID: 9975836 DOI: 10.1103/physrevb.50.14911] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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364
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Tarshis LC, Yan M, Poulter CD, Sacchettini JC. Crystal structure of recombinant farnesyl diphosphate synthase at 2.6-A resolution. Biochemistry 1994; 33:10871-7. [PMID: 8086404 DOI: 10.1021/bi00202a004] [Citation(s) in RCA: 298] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The synthesis of farnesyl diphosphate (FPP), a key intermediate in the isoprenoid biosynthetic pathway required for the synthesis of cholesterol and in the formation of prenylated proteins, is catalyzed by the enzyme farnesyl diphosphate synthase (FPS). The crystal structure of avian recombinant FPS, the first three-dimensional structure for any prenyltransferase, was determined to 2.6-A resolution. The enzyme exhibits a novel fold composed entirely of alpha-helices joined by connecting loops. The enzyme's most prominent structural feature is the arrangement of 10 core helices around a large central cavity. Two aspartate-rich sequences that are highly conserved among the isoprenyl diphosphate synthase family of prenyltransferases, and are essential for enzymatic activity, were found on opposite walls of this cavity, with the aspartate side chains approximately 12 A apart and facing each other. The location and metal ion binding properties of these sequences suggest that the conserved aspartate residues participate in substrate binding of catalysis.
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365
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Yan M, Rothberg LJ, Papadimitrakopoulos F, Galvin ME, Miller TM. Defect quenching of conjugated polymer luminescence. PHYSICAL REVIEW LETTERS 1994; 73:744-747. [PMID: 10057526 DOI: 10.1103/physrevlett.73.744] [Citation(s) in RCA: 183] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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366
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Yan M, Templeton DJ. Identification of 2 serine residues of MEK-1 that are differentially phosphorylated during activation by raf and MEK kinase. J Biol Chem 1994; 269:19067-73. [PMID: 8034665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The signal transduction kinase MEK (mitogen-activated protein (MAP) or extracellular signal-regulated (Erk) kinase)-1 is activated via phosphorylation by MEKK (MEK kinase) and raf kinases. We show here that these two kinases phosphorylate rat MEK-1 exclusively on two serine codons, Ser218 and Ser222. Phosphorylation of MEK-1 on serines 218 and 222 is both necessary and sufficient for MEK-1 to be activated and able to phosphorylate MAP kinase. A mutant form of MEK-1 that replaces these two codons with alanine cannot be activated, and one that substitutes glutamic acid residues in place of these 2 serines is active independent of activation by phosphorylation. These sites of activation occur in a region of MEK-1 that is similar to sites of activating phosphorylation in several other serine/threonine kinases, suggesting that this region may represent a conserved "activating domain" of many kinases. MEKK and raf display differences in site preference between these two codons, with MEKK showing preference for the amino acid at codon 218 and raf phosphorylating each residue approximately equally. This site preference might result in differences in the temporal or subsequent substrate patterns of MEK activation that result from these two activation pathways.
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367
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Yan M, Templeton D. Identification of 2 serine residues of MEK-1 that are differentially phosphorylated during activation by raf and MEK kinase. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32275-5] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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368
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Yan M, Rothberg L, Hsieh BR, Alfano RR. Exciton formation and decay dynamics in electroluminescent polymers observed by subpicosecond stimulated emission. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:9419-9422. [PMID: 10009740 DOI: 10.1103/physrevb.49.9419] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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369
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Yan M, Cai SX, Wybourne MN, Keana JF. N-hydroxysuccinimide ester functionalized perfluorophenyl azides as novel photoactive heterobifunctional cross-linking reagents. The covalent immobilization of biomolecules to polymer surfaces. Bioconjug Chem 1994; 5:151-7. [PMID: 8031878 DOI: 10.1021/bc00026a007] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The synthesis of N-hydroxysuccinimide (NHS) functionalized perfluorophenyl azides (PFPAs) 2 and 3 is described together with a general method for the covalent modification of polymer surfaces using heterobifunctional, photoactivable cross-linking reagents 1 and 3. The NHS-active ester group becomes covalently attached to the polymer surface via an efficient CH bond insertion reaction of the photogenerated, highly reactive nitrene intermediate derived from the PFPA. The NHS ester is capable of further reaction with a variety of primary amine-containing reagents including biomolecules by way of amide formation. The method is illustrated as follows. Photolysis of polystyrene (PS) and poly-(3-octylthiophene) (P3OT) thin films spin-coated with NHS PFPA ester 1 or 3 gave films 8 or 9, respectively. Each film was then exposed to an aqueous solution of horseradish peroxidase (HRP), giving films 10 or 11, respectively. The amounts of HRP immobilized on PS and P3OT were calculated from enzyme activity assays to be 0.5 +/- 0.1 ng/mm2 for 10a, 1.0 +/- 0.2 ng/mm2 for 11a, 0.2 +/- 0.1 ng/mm2 for 10b, 0.3 +/- 0.1 ng/mm2 for 11b. Using this surface functionalization methodology, biotin-streptavidin-biotin-HRP was constructed on the PS film. The storage stability of HRP thus immobilized through the extended linker, biotin-streptavidin-biotin, was enhanced as compared to that of HRP directly immobilized on the PS surface.
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370
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Yan M, Rothberg LJ, Papadimitrakopoulos F, Galvin ME, Miller TM. Spatially indirect excitons as primary photoexcitations in conjugated polymers. PHYSICAL REVIEW LETTERS 1994; 72:1104-1107. [PMID: 10056618 DOI: 10.1103/physrevlett.72.1104] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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371
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Mei QD, Yan M, Huang XL. [Immunohistochemical study and treatment result of small cell lung carcinoma using combination chemotherapy]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1994; 16:43-6. [PMID: 8033748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Sixty eight cases of small cell lung carcinoma (SCLC) were treated with Combination chemotherapy regimen of COCE or COMP. Among them, 22 cases received radiotherapy after chemotherapy, and 14 cases were studied with antibodies of NSE (neuron-specific enolase), CCH-A (chromogranin A), CEA (carcino-embryonic antigen) and keratin using an immunohistochemical ABC method. The total remission rate was 58.8% and the MST was 12.8 months. The CR+PR of COCE treated group was 74.3% and the MST was 12.9 months. The CR+PR of COMP treated group was 37.8% and the MST was 10 months. There was statistically significant difference between results of the COCE and COMP-treated groups. The MST of cases who received radiotherapy after chemotherapy was 15 months (COCE 17.3 months, COMP 12 months). It indicated that COCE regimen was more effective than COMP one. The immunohistochemical result showed that 44.4% (6/14) of the cases were positive with NSE and/or CCH-A, and their MAT was longer than that of NSE and/or CCH-A negative cases. It suggests that SCLC with neuroendocrine differentiation has a better prognosis.
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373
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Hsu JW, Yan M, Jedju TM, Rothberg LJ, Hsieh BR. Assignment of the picosecond photoinduced absorption in phenylene vinylene polymers. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:712-715. [PMID: 10009349 DOI: 10.1103/physrevb.49.712] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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374
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Hawkins JG, Lee LC, Yan M, Lin Y, Perkins FW, Yamada M. A mechanism to produce a dawn-dusk component of plasma flow during magnetic reconnection in the magnetotail. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/93ja02269] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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375
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Xing SH, Ge XQ, Yan M, Bian CF. [Effects of dl-tetrahydropalmatine on blood pressure and norepinephrine and epinephrine contents in peripheral tissues]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1994; 15:92-6. [PMID: 8010098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Administration of dl-tetrahydropalmatine (THP) i.v., ip, and ig lowered the pressure and concurrently slowed the heart rate in anesthetized rats. The hypotensive and bradycardic effects were not produced by injecting THP into the vertebral artery in anesthetized rabbits. These results suggest that the site of hypotensive action of THP may not be a central one. The HPLC coupled with electrochemical detection showed that the contents of norepinephrine (NE) in the heart, aorta, and femoral artery and epinephrine (E) in the adrenal gland were markedly reduced by THP (P < 0.01). A positive correlation was found between the hypotensive effect and the reduction of NE in the aorta and femoral artery (r = 0.97, P < 0.01).
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