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1.
J Geophys Res Space Phys ; 127(4): e2021JA030238, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35866072

ABSTRACT

Discrete aurora at Mars, characterized by their small spatial scale and tendency to form near strong crustal magnetic fields, are emissions produced by particle precipitation into the Martian upper atmosphere. Since 2014, Mars Atmosphere and Volatile EvolutioN's (MAVEN's) Imaging Ultraviolet Spectrograph (IUVS) has obtained a large collection of UV discrete aurora observations during its routine periapsis nightside limb scans. Initial analysis of these observations has shown that, near the strongest crustal magnetic fields in the southern hemisphere, the IUVS discrete aurora detection frequency is highly sensitive to the interplanetary magnetic field (IMF) clock angle. However, the role of other solar wind properties in controlling the discrete aurora detection frequency has not yet been determined. In this work, we use the IUVS discrete aurora observations, along with MAVEN observations of the upstream solar wind, to determine how the discrete aurora detection frequency varies with solar wind dynamic pressure, IMF strength, and IMF cone angle. We find that, outside of the strong crustal field region (SCFR) in the southern hemisphere, the aurora detection frequency is relatively insensitive to the IMF orientation, but significantly increases with solar wind dynamic pressure, and moderately increases with IMF strength. Interestingly however, although high solar wind dynamic pressures cause more aurora to form, they have little impact on the brightness of the auroral emissions. Alternatively, inside the SCFR, the detection frequency is only moderately dependent on the solar wind dynamic pressure, and is much more sensitive to the IMF clock and cone angles. In the SCFR, aurora are unlikely to occur when the IMF points near the radial or anti-radial directions when the cone angle (arccos(B x /|B|)) is less than 30° or between 120° and 150°. Together, these results provide the first comprehensive characterization of how upstream solar wind conditions affect the formation of discrete aurora at Mars.

2.
Oper Dent ; 42(1): 19-29, 2017.
Article in English | MEDLINE | ID: mdl-28002695

ABSTRACT

The aim of this randomized controlled clinical trial was to compare the clinical effectiveness of different polishing systems and self-etch adhesives in class V composite resin restorations. A total of 164 noncarious cervical lesions (NCCLs) from 35 patients were randomly allocated to one of four experimental groups, each of which used a combination of polishing systems and adhesives. The two polishing systems used were Sof-Lex XT (Sof), a multistep abrasive disc, and Enhance/Pogo (EP), a simplified abrasive-impregnated rubber instrument. The adhesive systems were Clearfil SE bond (CS), a two-step self-etch adhesive, and Xeno V (XE), a one-step self-etch adhesive. All NCCLs were restored with light-cured microhybrid resin composites (Z250). Restorations were evaluated at baseline and at 6, 12, 18, and 24 months by two blinded independent examiners using modified FDI criteria. The Fisher exact test and generalized estimating equation analysis considering repeated measurements were performed to compare the outcomes between the polishing systems and adhesives. Three restorations were dislodged: two in CS/Sof and one in CS/EP. None of the restorations required any repair or retreatment except those showing retention loss. Sof was superior to EP with regard to surface luster, staining, and marginal adaptation (p<0.05). CS and XE did not show differences in any criteria (p>0.05). Sof is clinically superior to EP for polishing performance in class V composite resin restoration. XE demonstrates clinically equivalent bonding performance to CS.


Subject(s)
Acid Etching, Dental/methods , Composite Resins/chemistry , Dental Polishing/methods , Dental Restoration, Permanent/methods , Adult , Aged , Dental Cements , Esthetics, Dental , Female , Humans , Light-Curing of Dental Adhesives , Male , Middle Aged , Prospective Studies , Resin Cements , Surface Properties
3.
Science ; 350(6261): aad0313, 2015 Nov 06.
Article in English | MEDLINE | ID: mdl-26542577

ABSTRACT

Planetary auroras reveal the complex interplay between an atmosphere and the surrounding plasma environment. We report the discovery of low-altitude, diffuse auroras spanning much of Mars' northern hemisphere, coincident with a solar energetic particle outburst. The Imaging Ultraviolet Spectrograph, a remote sensing instrument on the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, detected auroral emission in virtually all nightside observations for ~5 days, spanning nearly all geographic longitudes. Emission extended down to ~60 kilometer (km) altitude (1 microbar), deeper than confirmed at any other planet. Solar energetic particles were observed up to 200 kilo--electron volts; these particles are capable of penetrating down to the 60 km altitude. Given minimal magnetic fields over most of the planet, Mars is likely to exhibit auroras more globally than Earth.

4.
Arch Pharm Res ; 24(5): 390-6, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11693537

ABSTRACT

Synthesized 6-arylamino-5,8-quinolinediones 4a-4j and 6-chloro-7-arylamino-5,8-isoquinolinediones 5a-5g were evaluated for effects on NAD(P)H: quinone oxidoreductase (NQO1) activity with the cytosolic fractions derived from cultured human lung cancer cells and their cytotoxicity in cultured several human solid cancer cell lines. The 5,8-quinolinediones 4 and 5,8-isoquinolinediones 5 affected the reduction potential by NQO1 activity and showed a potent cytotoxic activity against human cancer cell lines. The tested compounds 4a, 5c, 5f, and 5g were considered as more potent cytotoxic agents. The compounds 4d, 5b, 5c, 5e and 5g were comparable modulators of NQO1 activity.


Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , NAD(P)H Dehydrogenase (Quinone)/antagonists & inhibitors , Quinolones/chemical synthesis , Quinolones/pharmacology , Quinones/chemical synthesis , Quinones/pharmacology , Cell Survival/drug effects , Humans , Indicators and Reagents
5.
Bioorg Med Chem ; 9(11): 2979-86, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11597479

ABSTRACT

We report upon the synthesis of the following derivatives: N-substituted-pyridino[2,3-f]indole-4,9-dione, and 6-(alpha-diethoxycarbonyl-methyl)-7-substituted-amino-quinoline-5,8-dione, which contain the active quinoline-5,8-dione (VII) moiety. The cytotoxic activities of these compounds have been tested in SRB (SulfoRhodamine B) assays against the cancer cell lines of A-549 (human lung cancer), SK-MEL-2 (human melanoma cancer), SK-OV-3 (human ovarian cancer), XF-498 (human brain cancer) and HCT 15 (human colon cancer). The compound, N-benzyl-3-ethoxycarbonyl-2-hydroxy-pyridino[2,3-f]indole-4,9-dione (A-9), also showed higher activity than cis-platin. The highest level of cytotoxic activity in these human tumor cell lines was observed in the compound 6-(alpha-diethoxycarbonyl-methyl)-7-(2-methyl-phenylamino)-quinoline-5,8-dione (B-3).


Subject(s)
Antineoplastic Agents/chemical synthesis , Indoles/pharmacology , Quinolones/pharmacology , Quinones/pharmacology , Antineoplastic Agents/pharmacology , Cell Division/drug effects , Drug Screening Assays, Antitumor , Humans , Indoles/chemical synthesis , Indoles/chemistry , Inhibitory Concentration 50 , Protein Biosynthesis , Proteins/drug effects , Pyridines/chemical synthesis , Pyridines/chemistry , Pyridines/pharmacology , Quinolones/chemical synthesis , Quinolones/chemistry , Quinones/chemical synthesis , Quinones/chemistry , Structure-Activity Relationship , Tumor Cells, Cultured/drug effects
6.
J Nat Prod ; 64(10): 1301-4, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11678655

ABSTRACT

Five new (1-3, 5, and 7) and two known (4, 6) furanosesterterpene tetronic acids were isolated from the marine sponge Sarcotragus sp. by bioactivity-guided fractionation. These compounds showed cytotoxicity against a panel of five human tumor cell lines. The gross structures were established on the basis of NMR and MS analyses. The compounds showed interesting variations of geometry and absolute configuration.


Subject(s)
Antineoplastic Agents/isolation & purification , Furans/isolation & purification , Porifera/chemistry , Terpenes/isolation & purification , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Artemia/drug effects , Chromatography, High Pressure Liquid , Circular Dichroism , Colonic Neoplasms , Drug Screening Assays, Antitumor , Female , Furans/chemistry , Furans/pharmacology , Humans , Inhibitory Concentration 50 , Korea , Larva/drug effects , Lung Neoplasms , Magnetic Resonance Spectroscopy , Molecular Structure , Neoplasms, Nerve Tissue , Ovarian Neoplasms , Skin Neoplasms , Spectrophotometry, Infrared , Spectroscopy, Fourier Transform Infrared , Stereoisomerism , Structure-Activity Relationship , Terpenes/chemistry , Terpenes/pharmacology , Tumor Cells, Cultured/drug effects
7.
Arch Pharm Res ; 24(4): 276-80, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11534756

ABSTRACT

Substituted isoquinolin-1-ones (1) were synthesized to test their in vitro anticancer activity. 3-Biphenyl-N-methylisoquinolin-1-one (7) showed the most potent anticancer activity against five different human cancer cell lines.


Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Isoquinolines/chemical synthesis , Isoquinolines/pharmacology , Drug Screening Assays, Antitumor , Humans , Indicators and Reagents , Magnetic Resonance Spectroscopy , Structure-Activity Relationship , Tumor Cells, Cultured
8.
J Nat Prod ; 64(8): 1059-63, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11520227

ABSTRACT

Ten new (1, 4-6, 9-14) and four known (2, 3, 7, 8) diacetylenes have been isolated from a brine shrimp active fraction of the methanolic extract of the stony coral Montipora sp. The structures were determined by combined spectroscopic methods. The compounds exhibited significant cytotoxicity against a small panel of human solid tumor cell lines. Montiporyne A (15), a previously reported congener, was also found to induce apoptosis in human colon tumor cell.


Subject(s)
Acetylene/isolation & purification , Antineoplastic Agents/isolation & purification , Cnidaria/chemistry , Acetylene/analogs & derivatives , Acetylene/chemistry , Acetylene/pharmacology , Alkynes , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Chromatography, High Pressure Liquid , Colonic Neoplasms , Humans , Korea , Magnetic Resonance Spectroscopy , Molecular Structure , Stereoisomerism , Tumor Cells, Cultured/drug effects , Tumor Cells, Cultured/metabolism , X-Ray Diffraction
9.
J Cardiovasc Pharmacol ; 38(1): 11-20, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11444494

ABSTRACT

Polychlorinated biphenyls (PCBs) have been known as serious environmental pollutants, causing developmental delays, motor dysfunction, and decrease in brain dopamine level in humans and animals. We have investigated the effects of a PCB congener, 2,2',6-trichlorobiphenyl (PCB 19) on contractile force, Ca2+ transient, and L-type Ca2+ current (I(Ca,L)) in guinea pig ventricular myocytes stimulated at a rate of 0.25-0.33 Hz. PCB 19 decreased contractile force in a concentration-dependent manner. During the negative inotropic response, the action potential duration at 20% (APD20), 90% of repolarization (APD90), and the action potential amplitude (APA) were decreased concentration dependently: 30 microM PCB 19 reduced APD20, APD90 and APA by 36.7 +/- 3.5%, 22.6 +/- 3.9%, and 2.4 +/- 0.6%, respectively (n = 11, p < 0.01). PCB 19 30 microM decreased the Ca2+ transient and the I(Ca,L) by 46.8 +/- 1.8% (n = 9, p < 0.01) and 47.1 +/- 3.1% (n = 9, p < 0.01), respectively. The results suggest that PCB 19 decreased the Ca2+ transient through inhibition of L-type Ca2+ channels and that the decreased Ca2+ transient consequently caused a negative inotropic effect in cardiac myocytes.


Subject(s)
Calcium Channels, L-Type/physiology , Environmental Pollutants/pharmacology , Myocardial Contraction/drug effects , Myocardium/metabolism , Animals , Guinea Pigs , Membrane Potentials/drug effects , Membrane Potentials/physiology , Myocardial Contraction/physiology , Myocardium/cytology , Polychlorinated Biphenyls/pharmacology
10.
J Nat Prod ; 64(7): 956-7, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11473434

ABSTRACT

A new pyridinium alkaloid, montipyridine (1), has been isolated from the stony coral Montipora sp. The structure was established from spectroscopic data.


Subject(s)
Alkaloids/isolation & purification , Cnidaria/chemistry , Pyridinium Compounds/isolation & purification , Alkaloids/chemistry , Animals , Chromatography, High Pressure Liquid , Korea , Magnetic Resonance Spectroscopy , Molecular Structure , Pyridinium Compounds/chemistry
11.
Planta Med ; 67(4): 358-9, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11458455

ABSTRACT

Costunolide, a germacrane sesquiterpene lactone isolated from the stem bark of Magnolia sieboldii demonstrated a significant inhibition upon the farnesylation process of human lamin-B by farnesyl-proteintransferase (FPTase), in a dose dependent manner in vitro (IC50 value was calculated as 20 microM). It was also found to exhibit an inhibition upon the proliferation of cultured human tumor cells, i.e., A549 (non small cell lung), SK-OV-3 (ovary), SK-MEL-2 (melanoma), XF498 (central nerve system) and HCT-15 (colon), in vitro.


Subject(s)
Alkyl and Aryl Transferases/antagonists & inhibitors , Antineoplastic Agents, Phytogenic/isolation & purification , Antineoplastic Agents, Phytogenic/pharmacology , Drugs, Chinese Herbal/chemistry , Enzyme Inhibitors/pharmacology , Plants, Medicinal/chemistry , Sesquiterpenes/isolation & purification , Sesquiterpenes/pharmacology , Tumor Cells, Cultured/drug effects , Amino Acid Sequence , Animals , Antineoplastic Agents, Phytogenic/chemistry , Brain/enzymology , Humans , Magnetic Resonance Spectroscopy , Molecular Structure , Plant Shoots/chemistry , Rats , Sesquiterpenes/chemistry
12.
J Nat Prod ; 64(4): 533-5, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11325244

ABSTRACT

A known (1) and four new (2--5) lyso-PAF (platelet activating factor) derivatives were isolated from the sponge Spirastrella abata. Two of them are unprecedented in having a methoxy group at C-2'. The structures have been determined by combined spectroscopic methods. Their inhibitory effect on the biosynthesis of cholesterol and cytotoxicity against human solid tumor cell lines are reported.


Subject(s)
Platelet Activating Factor/analogs & derivatives , Platelet Activating Factor/isolation & purification , Animals , Magnetic Resonance Spectroscopy , Mass Spectrometry , Platelet Activating Factor/chemistry , Porifera
13.
J Nat Prod ; 64(12): 1565-7, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11754614
14.
Anticancer Drugs ; 11(9): 715-25, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11129734

ABSTRACT

A new class of water-soluble cyclotriphosphazene-(diamine)platinum(II) conjugate drugs [NP(Am-Li2)(Am.PtA2)]3 (Am: dicarboxylic amino acid; A2: diamine) has been synthesized and characterized by means of elemental analysis, multinuclear (1H, 31P, 13C, 195Pt) NMR and IR spectroscopies. All the title compounds were subjected to both in vitro and in vivo assays against the murine leukemia L1210 cell line and selected human tumor cells. Most of the title compounds have shown higher in vivo antitumor activity than cisplatin and carboplatin, and, in particular, [NP(L-Glu-Li2)(L-Glu.Pt(-dach)]3 (Glu=glutamate, dach=trans(+/-)-1,2-diaminocyclohexane) showed extraordinary high activity (ILS>500%) equally against both parent and cisplatin-resistant leukemia L1210 cell lines. Furthermore, this candidate compound (KI 60606) exhibited a wider spectrum of in vitro activity by showing higher cytotoxicity against all the selected human tumor cells than cisplatin and, therefore, was subjected to preclinical studies which are now near completion.


Subject(s)
Antineoplastic Agents/chemical synthesis , Nitriles/chemical synthesis , Organoplatinum Compounds/chemical synthesis , Phosphorus Compounds/chemical synthesis , Animals , Antineoplastic Agents/pharmacology , Drug Screening Assays, Antitumor , Humans , Leukemia L1210/drug therapy , Magnetic Resonance Spectroscopy , Mice , Nitriles/pharmacology , Organoplatinum Compounds/pharmacology , Phosphorus Compounds/pharmacology , Tumor Cells, Cultured/drug effects
15.
Clin J Oncol Nurs ; 4(2): 67-71, 2000.
Article in English | MEDLINE | ID: mdl-11107378

ABSTRACT

Gynecologic cancers will account for approximately 81,000 new cases of cancer this year. Although much is known about the risk factors for cervical, ovarian, and endometrial cancers, less is known about vaginal and vulvar cancer risk factors. Generally, risk factors and associations for gynecologic cancers are behavioral, reproductive, hormonal, and genetic related. Research continues to verify and refute the impact of certain factors. All nurses must be knowledgeable about the risk factors and associations for these cancers.


Subject(s)
Genital Neoplasms, Female/epidemiology , Genital Neoplasms, Female/etiology , Female , Genital Neoplasms, Female/classification , Genital Neoplasms, Female/pathology , Global Health , Humans , Oncology Nursing , Risk Factors , United States/epidemiology
16.
Clin J Oncol Nurs ; 4(2): 73-7, 2000.
Article in English | MEDLINE | ID: mdl-11107379

ABSTRACT

Screening interventions for gynecologic cancers involve identifying risk factors and high-risk groups of women, counseling for risk factor reduction, and recommending early detection strategies. All nurses can conduct gynecologic risk assessments, and advanced practice nurses can perform physical exams. All women must be knowledgeable about risk factors because gynecologic cancers are curable when diagnosed in the early stages. Nursing interventions include developing culturally sensitive programs and educational materials for targeted populations and educating women in all groups to raise awareness about gynecologic cancer risks.


Subject(s)
Genital Neoplasms, Female/diagnosis , Genital Neoplasms, Female/etiology , Mass Screening/methods , Age Distribution , Age Factors , Female , Genital Neoplasms, Female/epidemiology , Genital Neoplasms, Female/nursing , Humans , Medical History Taking/methods , Nurse Clinicians , Oncology Nursing , Physical Examination/methods , Risk Assessment , Risk Factors
17.
J Nat Prod ; 63(11): 1511-4, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11087594

ABSTRACT

Six new acetylenic compounds (1-6) with cytotoxic activities against human solid tumor cell lines (SK-OV-3, SK-MEL-2, XF498, and HCT15) have been isolated from the stony coral Montipora sp. Structures of the compounds 1-6 were elucidated based on analysis of the NMR and MS data.


Subject(s)
Antineoplastic Agents/isolation & purification , Cnidaria/chemistry , Fatty Acids, Unsaturated/isolation & purification , Animals , Antineoplastic Agents/pharmacology , Artemia , Chromatography, High Pressure Liquid , Drug Screening Assays, Antitumor , Fatty Acids, Unsaturated/pharmacology , Humans , Korea , Magnetic Resonance Spectroscopy
18.
J Cell Physiol ; 185(2): 200-6, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11025441

ABSTRACT

We investigated the expression of ryanodine receptors (RyRs) in cultured human melanocytes with immunocytochemistry and reverse transcriptase-polymerase chain reaction. With the use of a monoclonal antibody, RyR immunoreactivity was detected in the cytoplasm of melanocytes, and was further confirmed by RT-PCR assay. The PCR products were cut with restriction enzymes specific for each RyR isoform. Using the RyR1-specific restriction enzyme SacI yielded fragments of 300, 100, and 130 base pairs, consistent with the expression of RyR1 isoforms. The function of RyR in Ca(2+) signaling was investigated using single-cell fura-2 imaging. Ryanodine (1 to approximately 100 microM) induced significant elevation of cytoplasmic Ca(2+) in single human melanocytes in a dose-dependent manner. The ryanodine-induced [Ca(2+)](i) increase was inhibited by neomycin. Furthermore, ryanodine inhibited proliferation and stimulated pigmentation of human melanocytes. This study demonstrates that the RyR1 isoform is expressed in cultured human melanocytes, and suggests that the RyR may be involved in regulating the intracellular Ca(2+) responses involved in proliferation and pigmentation of cultured human melanocytes.


Subject(s)
Melanocytes/metabolism , Ryanodine Receptor Calcium Release Channel/metabolism , Calcium/metabolism , Cell Division/drug effects , Cells, Cultured , Cytosol/metabolism , Humans , Melanocytes/physiology , Osmolar Concentration , Pigmentation/drug effects , Ryanodine/pharmacology
19.
Bioorg Med Chem ; 8(8): 2079-83, 2000 Aug.
Article in English | MEDLINE | ID: mdl-11003153

ABSTRACT

2-Methyl-1-substituted-imidazo[4,5-g]quinoline-4,9-diones and 7,8-dihydro-10H-[1,4]oxazino-[3',4':2,3]imidazo[4,5-g]quinoline-5, 12-dione (19) derivatives have been synthesized from 6,7-dichloro-5,8-quinolinedione for developing the new anticancer drugs. Our study on the cytotoxicity of imidazoquinolinedione derivatives has revealed that 7,8-dihydro-10H-[1,4]oxazino-[3',4':2,3]imidazo[4,5-g]quinoline-5, 12-dione (19), a tetracyclic heteroquinone analogue, exhibited high cytotoxicity on human colon tumor cell (HCT 15) in vitro SRB assay. The IC50 value of this compound was 0.026 microg/mL whereas those of doxorubicin and cisplatin were 0.023 microg/mL and 1.482 microg/mL, respectively. Meanwhile compounds 5-7 and 12 in the series of 1-substituted-imidazoquinolinediones showed relatively good activity on human brain tumor cell lines (XF 498).


Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Imidazoles/chemical synthesis , Imidazoles/pharmacology , Quinolines/chemical synthesis , Quinolines/pharmacology , Antineoplastic Agents/chemistry , Drug Screening Assays, Antitumor , Humans , Imidazoles/chemistry , Intercalating Agents/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure , Quinolines/chemistry , Structure-Activity Relationship , Tumor Cells, Cultured
20.
Am J Physiol Heart Circ Physiol ; 279(4): H1661-8, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11009453

ABSTRACT

We investigated the role of protein kinase C (PKC) in alpha(1)-adrenergic regulation of intracellular Na(+) activity (a(Na)(i)) in single guinea pig ventricular myocytes. a(Na)(i) and membrane potentials were measured with the Na(+)-sensitive indicator sodium-binding benzofuran isophthalate and conventional microelectrodes, respectively, at room temperature (24-26 degrees C) while myocytes were stimulated at a rate of 0.25-0.3 Hz. The PKC activator 4beta-phorbol 12-myristate 13-acetate (PMA) decreased a(Na)(i) in a concentration-dependent manner. PMA (100 nM) produced a maximal decrease in a(Na)(i) of 1.5 mM from 6.5 +/- 0.4 to 5.0 +/- 0.4 mM (means +/- SE, n = 12, P < 0.01). The PMA concentration required for a half-maximal decrease in a(Na)(i) was 0.46 +/- 0.13 nM (n = 3, P < 0.01). An inactive phorbol, 4alpha-phorbol 12-myristate 13-acetate, did not decrease a(Na)(i). The decrease caused by PMA could be blocked by the PKC inhibitors staurosporine and bisindolylmaleimide I (GF-109203X). Stimulation of the alpha(1)-adrenoceptor with 50 microM phenylephrine decreased a(Na)(i) from 6.1 +/- 0.3 to 4.6 +/- 0.3 mM (n = 11, P < 0.01). The decrease in a(Na)(i) produced by phenylephrine was blocked by pretreatment with staurosporine, GF-109203X, or PMA. The decrease in a(Na)(i) produced by PMA was not prevented by pretreatment with tetrodotoxin but was blocked by pretreatment with strophanthidin or high extracellular K(+) concentration. The results suggest that alpha(1)-adrenergic receptor activation results in a decrease in a(Na)(i) via PKC-induced stimulation of the Na(+)-K(+) pump in cardiac myocytes.


Subject(s)
Intracellular Membranes/metabolism , Myocardium/metabolism , Protein Kinase C/physiology , Receptors, Adrenergic, alpha/physiology , Sodium/metabolism , Adrenergic alpha-Agonists/pharmacology , Animals , Enzyme Inhibitors/pharmacology , Extracellular Space/metabolism , Guinea Pigs , Heart Ventricles , Indoles/pharmacology , Maleimides/pharmacology , Myocardium/cytology , Phenylephrine/pharmacology , Potassium/metabolism , Protein Kinase C/antagonists & inhibitors , Sodium/antagonists & inhibitors , Staurosporine/pharmacology , Strophanthidin/pharmacology , Tetradecanoylphorbol Acetate/pharmacology , Tetrodotoxin/pharmacology
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