DOCSLIB.ORG

Role of Polyamine-Regulated KATP Channels

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Role of Polyamine-Regulated KATP Channels Retinal Cell Biology Vulnerability of the Retinal Microvasculature to Hypoxia: Role of Polyamine-Regulated KATP Channels Atsuko Nakaizumi1 and Donald G. Puro1,2 PURPOSE. It is uncertain why retinal capillaries are particularly of retinal vascular disorders. Here, we considered the idea that vulnerable to hypoxia. In this study, it was hypothesized that specialized physiological adaptations of the retinal capillaries their specialized physiology, which includes being the predom- boost their vulnerability to hypoxia. inant microvascular location of functional adenosine triphos- Evidence is accumulating that within the circulatory system 1–3 phate-sensitive potassium (KATP) channels, boosts their suscep- of the retina, there is functional specialization. For exam- tibility to hypoxia-induced cell death. ple, most of the functional adenosine triphosphate-sensitive 2 METHODS. Cell viability, ionic currents, intracellular calcium, potassium (KATP) channels are located in the capillaries. In and pericyte contractility in microvascular complexes freshly contrast, the activity of voltage-dependent calcium channels isolated from the rat retina were assessed using trypan blue dye (VDCCs) is minimal in this microvascular region, but is robust 3 exclusion, perforated-patch recordings, fura-2 fluorescence, in the precapillary tertiary arterioles. An important opera- and time-lapse videos. Chemical hypoxia was induced by anti- tional result of this topographical distribution of ion channels mycin, an oxidative phosphorylation inhibitor. is that the hyperpolarizing KATP current activated by vasoactive signals, such as adenosine, is generated almost exclusively in RESULTS. In freshly isolated retinal microvascular complexes, 2 chemical hypoxia caused more cell death in capillaries than in the capillaries and must be transmitted proximally to micro- arterioles. Indicative of the role of polyamine-dependent K vascular sites where VDCCs are available to transduce the ATP induced voltage change into a vasomotor response that alters channels, antimycin-induced capillary cell death was markedly 2,3 decreased in microvessels treated with the polyamine synthesis blood flow. Although this functional specialization within the retinal microvasculature appears to be important for the inhibitor, difluoromethylornithine, or the KATP channel inhib- itor, glibenclamide. These inhibitors also diminished the anti- effective regulation of local perfusion, we hypothesized that mycin-induced hyperpolarization, as well as the antimycin- the abundance of KATP channels may boost the vulnerability of induced intracellular calcium increase, which was significantly the capillaries to hypoxic damage. dependent on extracellular calcium and was diminished by the How could an abundance of KATP channels boost capillary inhibitor of calcium-induced calcium release (CICR), dan- vulnerability to hypoxia? We posited that a hypoxia-induced trolene. Consistent with the importance of the CICR-depen- drop in the ATP concentration activates the capillary KATP dent increase in capillary cell calcium, dantrolene significantly channels, whose function is inhibited by intracellular ATP. Due to the hypoxia-induced activation of KATP channels, increased decreased hypoxia-induced capillary cell death. We also found ϩ 2ϩ K efflux via these channels would cause hyperpolarization, that activation of the polyamine/KATP channel/Ca influx/ CICR pathway not only boosted the vulnerability of retinal which in turn, would increase the electrochemical gradient for capillaries to hypoxia, but also caused the contraction of cap- the influx of calcium via nonspecific cation (NSC) channels, illary pericytes, whose vasoconstrictive effect may exacerbate which are the predominant calcium-permeable ion channels 4 hypoxia. expressed in retinal capillaries. Because increased intracellu- lar calcium is known to exacerbate hypoxic damage in a variety CONCLUSIONS. The vulnerability of retinal capillaries to hyp- of cell types,5,6 we proposed a working model in which the oxia is boosted by a mechanism involving the polyamine/ 2ϩ KATP channel-dependent increase in cell calcium boosts the KATP channel/Ca influx/CICR pathway. Discovery of this pathway should provide new targets for pharmacological vulnerability of retinal capillaries to hypoxia. In addition to K channels, we hypothesized that endog- interventions to minimize hypoxia-induced damage in retinal ATP capillaries. (Invest Ophthalmol Vis Sci. 2011;52:9345–9352) enous polyamines play a role in establishing the vulnerability of DOI:10.1167/iovs.11-8176 retinal capillaries to hypoxia. These ornithine-derived mole- cules were of interest because we found previously2 that the function of microvascular K channels, which are redox- his study addressed the question of why the capillaries of ATP sensitive,2 is dependent on endogenous polyamines, whose the retina are particularly prone to hypoxia-induced cell T catabolism generates H O .7 Consistent with polyamines hav- damage and death, which occurs during the course of a variety 2 2 ing a role in capillary cell death, these molecules are known to modulate death pathways in a variety of cell types,8 although its diversity of effects, which include enhancing and inhibiting From the Departments of 1Ophthalmology and Visual Sciences cell death, remain confounding, and the mechanisms by which and 2Molecular and Integrative Physiology, University of Michigan, Ann polyamines affect cell viability are incompletely understood. In Arbor, Michigan. this study, we tested the novel hypothesis that by regulating Supported by National Institutes of Health Grants EY12505 and the function of KATP channels, endogenous polyamines may EY07003. play a role in establishing the lethality of hypoxia in the cap- Submitted for publication July 6, 2011; revised October 19, 2011; illaries of the retina. accepted October 23, 2011. Disclosure: A. Nakaizumi, None; D.G. Puro, None We report that in freshly isolated retinal microvascular com- Corresponding author: Donald G. Puro, Department of Ophthal- plexes, the inhibitor of oxidative phosphorylation, antimycin A, mology and Visual Sciences, University of Michigan, 1000 Wall Street, causes substantially more cell death in the capillaries than in the Ann Arbor, MI 48505; [email protected]. precapillary arterioles. Experiments using the patch-clamp tech- Investigative Ophthalmology & Visual Science, December 2011, Vol. 52, No. 13 Copyright 2011 The Association for Research in Vision and Ophthalmology, Inc. 9345 Downloaded from iovs.arvojournals.org on 10/01/2021 9346 Nakaizumi and Puro IOVS, December 2011, Vol. 52, No. 13 nique, calcium-imaging, time-lapse photography, and the trypan Model of Hypoxia blue viability assay provided evidence that the greater vulnerabil- ity of the capillaries to hypoxia-induced cell death is due to the Chemical hypoxia was created by exposing isolated retinal microvas- activation of a pathway involving endogenous polyamines, hyper- cular complexes to the inhibitor of oxidative phosphorylation, antimy- cinA(5␮M). polarizing KATP channels, calcium influx, and calcium-induced calcium release (CICR). Our experimental results indicate that 2ϩ activation of the polyamine/KATP channel/Ca influx/CICR path- Cell Viability Assay way is a previously unappreciated mechanism by which the Microvascular cells that failed to exclude trypan blue dye were classi- vulnerability of retinal capillaries to hypoxia is boosted. fied as dead. As done previously,10–12 the trypan blue assay was performed by exposing microvessel-containing coverslips to 0.04% METHODS trypan blue in solution A for 15 minutes. After washing in solution A, microvessels were examined at magnification ϫ 100 with an inverted Animal use conformed to the guidelines of the ARVO Statement for the microscope equipped with bright-field optics. Because differences in Use of Animals in Ophthalmic and Vision Research and was approved abluminal cell density made it straightforward to distinguish precapil- by the University of Michigan Committee on the Use and Care of lary tertiary arterioles from the capillaries,1 cell viability was tallied Animals. This study used Long-Evans rats (Charles River, Cambridge, separately for these portions of the retinal microvasculature. For each MA), which were maintained on a 12-hour alternating light/dark cycle microvascular region, the percentage of the surveyed cells that were and had unrestricted access to water and food. trypan blue positive (i.e., dead), was calculated. Because trypan blue- containing cells typically were swollen, identification of these cells as Microvessel Isolation being endothelial or abluminal was uncertain, and thus, subclassifica- A previously described tissue print technique2 was used to isolate vast tion of microvascular cells into these two types was not done. microvascular complexes from the retinas of rats, which were killed Cell viability was initially quantified before the onset of antimycin with a rising concentration of carbon dioxide. In brief, the procedure exposure. In freshly isolated retinal microvascular complexes, cell for microvessel isolation included the rapid removal of retinas, exci- viability was high (i.e., 96.7 Ϯ 0.3; n ϭ 62 microvascular complexes, sion of adherent vitreous, and incubation for approximately 24 min- and 94.9 Ϯ 0.3; n ϭ 62 in tertiary arterioles and capillaries, respec- utes at 30°C in Earle’s balanced salt solution supplemented with 0.5 tively). In some experiments, freshly isolated microvascular complexes mM EDTA, 6 U papain (Worthington
Load more

Recommended publications
  • (N-BUTYL)-I,3-DIAMINOPROPANE on POLYAMINE METABOLISM, CELL GROWTH and SENSITIVITY to CHLOROETHYLATING AGENTS
    Biochemical Pharmacoh~gy. Vol. 46, No. 4, pp. 717-724, 1993. (101g~-2952/93 $6.1111 + (I.{KI Printed in Great Britain. © 1993. Pergamon Press Lid EFFECT OF N-(n-BUTYL)-I,3-DIAMINOPROPANE ON POLYAMINE METABOLISM, CELL GROWTH AND SENSITIVITY TO CHLOROETHYLATING AGENTS ANTHONY E. PEGG*'t" and JAMES K. COWARD~: *Departments of Cellular and Molecular Physiology and Pharmacology, Milton S. Hershey Medical Center. Pennsylvania State University College of Medicine, Hershey, PA 17033; and CDepartments of Chemistry and Medicinal Chemistry, The University of Michigan. Ann Arbor, MI 48109, U.S.A. (Received 29 January 1993: accepted 5 April 1993) Abstract--The effects of N-(n-butyl)-l,3-diaminopropane (BDAP) on cell growth and polyamine content were examined in L1210, SV-3T3 and HT-29 cells. In all cases, BDAP was a specific and highly effective inhibitor of spermine synthesis, and spermine levels were greatly suppressed in the presence of 50/LM BDAP. At the same time, there was a parallel increase in spermidine, which equalled or exceeded the fall in spermine so that total polyamine levels were not reduced. Cell growth was not affected in short-term experiments but culture of L1210 cells for 72-144 hr in the presence of BDAP did lead to an effect on growth that was reversed by the addition of spermine. These results suggest that, in the short term, a normal growth rate is maintained by spermidine but that a function or cellular component critically dependent on spermine becomes depleted at longer times. BDAP was a weak inducer of spermidine/spermine-Nl-acetyltransferase and this enzyme may be responsible for excretion or degradation of the inhibitor.
    [Show full text]
  • Article the Bee Hemolymph Metabolome: a Window Into the Impact of Viruses on Bumble Bees
    Article The Bee Hemolymph Metabolome: A Window into the Impact of Viruses on Bumble Bees Luoluo Wang 1,2, Lieven Van Meulebroek 3, Lynn Vanhaecke 3, Guy Smagghe 2 and Ivan Meeus 2,* 1 Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China; [email protected] 2 Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium; [email protected], [email protected] 3 Laboratory of Chemical Analysis, Department of Veterinary Public Health and Food Safety, Faculty of Vet- erinary Medicine, Ghent University, Merelbeke, Belgium; [email protected]; [email protected] * Correspondence: [email protected] Selection of the targeted biomarker set: In total we identified 76 metabolites, including 28 amino acids (37%), 11 carbohy- drates (14%), 11 carboxylic acids, 2 TCA intermediates, 4 polyamines, 4 nucleic acids, and 16 compounds from other chemical classes (Table S1). We selected biologically-relevant biomarker candidates based on a three step approach: (1) their expression profile in stand- ardized bees and its relation with viral presence, (2) pathways analysis on significant me- tabolites; and (3) a literature search to identify potential viral specific signatures. Step (1) and (2), pathways analysis on significant metabolites We performed two-way ANOVA with Tukey HSD tests for post-hoc comparisons and used significant metabolites for metabolic pathway analysis using the web-based Citation: Wang, L.L.; Van platform MetaboAnalyst (http://www.metaboanalyst.ca/) in order to get insights in the Meulebroek, L.; Vanhaecke.
    [Show full text]
  • Depletion of Cellular Glutathione by Exogenous Spermine in V79 Cells: Implications for Spermine-Induced Hyperthermic Sensitization
    [CANCER RESEARCH 45,4910-4914,1985] Depletion of Cellular Glutathione by Exogenous Spermine in V79 Cells: Implications for Spermine-induced Hyperthermic Sensitization Angelo Russo,1 James B. Mitchell, William DeGraff, Norman Friedman, and Janet Gamson Radiobiology Section, Radiation Oncology Branch, Division of Cancer Treatment, National Cancer Institute, NIH, Bethesda, MD 20205 ABSTRACT one is responsible in part for maintenance of the intracellular redox state (18) and since lowering intracellular levels of gluta The relationship between spermine-induced thermosensitiza- thione results in thermal sensitization, hyperthermia may be tion and modulation in the cellular redox state as measured by imposing an oxidative stress (19-21). As part of our general glutathione levels was studied using Chinese hamster V79 cells. interest in hyperthermia and the role that oxidative stress may Marked cellular glutathione depletion was observed for cells have on hyperthermic sensitization, the present study addresses treated with exogenous 1 mw spermine at 37°Cor 43°C. Glu the possible role of exogenously applied polyamines on the tathione depletion and thermal sensitization by spermine were cellular redox state. Our data show that exogenous polyamines found to be cell density dependent with maximum depletion and may impose an oxidative stress on cells partly reflected through sensitization observed at low cell densities. These findings are modulation of intracellular glutathione levels. discussed in the context that treatment of cells with exogenous polyamines such as spermine can result in cellular oxidative stress which may in part contribute to spermine-induced thermal MATERIALS AND METHODS sensitization. Cell Culture. Stock cultures of exponentially growing Chinese hamster V79 cells were grown in F12 medium supplemented with 10% fetal calf serum, penicillin, and streptomycin.
    [Show full text]
  • Spermine Product Number S3256 Store at 2-8 °C
    Spermine Product Number S3256 Store at 2-8 °C Product Description Proteins and protein complexes have been crystallized 19,20 Molecular Formula: C10H26N4 using spermine. Other applications of spermine Molecular Weight: 202.34 include its use as a matrix in MALDI-MS for analysis of CAS Number: 71-44-3 glycoconjugates and oligonucleotides.21,22 Melting Point: 55 - 60 °C1 28 - 30 °C2 Precautions and Disclaimer Synonym: N,N'-bis(3-aminopropyl)-1,4-butanediamine For Laboratory Use Only. Not for drug, household or other uses. Spermine is a naturally occuring polyamine that occurs in all eukaryotes, but is rare in prokaryotes. It is Preparation Instructions essential for cell growth in both normal and neoplastic This product is soluble in water (50 mg/ml), yielding a tissue.1 Spermine is formed through the addition of a clear, colorless to light yellow solution. aminopropyl group to spermidine by spermine synthase. Spermine is strongly basic in character, and Storage/Stability in aqueous solution at physiological pH, all of its amino Store at 2-8 °C. Solutions of spermine free base are groups will be positively charged.3 A review of the role readily oxidized. Solutions are most stable if prepared of spermine and other polyamines in affecting RNA in degassed water and stored in frozen aliquots, under structure and protein function has been published.4 argon or nitrogen gas. Spermine is commonly used in molecular biology and References biochemistry research. The polycationic character of 1. The Merck Index, 13th ed., Entry# 8817. spermine in solution allows for its use in the 2.
    [Show full text]
  • A Proposed Function for Spermine and Spermidine: Protection of Replicating DNA Against Damage by Singlet Oxygen (Sinlet Oxygen Q /Polymes) AHSAN U
    Proc. Natl. Acad. Sci. USA Vol. 89, pp. 11426-11427, December 1992 Biophysics A proposed function for spermine and spermidine: Protection of replicating DNA against damage by singlet oxygen (sinlet oxygen q /polymes) AHSAN U. KHANt, YING-HUA MEIt, AND THR3ISE WILSON* tDepartment of Pathology, Harvard Medical School, Boston, MA 02115; and *Department of Cellular and Developmental Biology, Harvard University, Cambridge, MA 02138 Communicated by Michael Kasha, August 31, 1992 (receivedfor review February 19, 1992) ABSTRACT Like al aiphatic i, the poya Aerated pyridine solutions of rubrene (0.22 mM) were spennne and sperme are ph l quncers of slt irradiated at 540 nm, and the concentration of rubrene was molecar oxygen (10?). The rate ant of these followed photometrically as a function of irradiation time, were determined in vitro with phocemcalygnrtoed down to a concentration ofrubrene ofabout one-halfits initial and the hydocbo rubrene a subste, i pyridie. At concentration; this was repeated in the presence of different milhmolar concentrt, Apmine and mide shol concentrations ofamines in the millimolarrange. Underthese quec 'o0 in vivo and prevt It from d DNA. It in conditions, ko/kA, the ratio of the pseudo-first-order rate proposed that a bk al nln of poyams I the pro- constant of decay of rubrene without amine to that with tection of repliang DNA against oxidative dama. amine, can be treated in a Stern-Volmer fashion. The slopes ofplots ofko/kA vs. amine concentration is kid, where is the ..... spermidine and spermine are widely distributed in lifetime of 102* in the absence of amine under the conditions nature, but their function is not known with any certainty" ofthe experiment.
    [Show full text]
  • Chromogenic Chemodosimeter Based on Capped Silica Particles to Detect Spermine and Spermidine
    nanomaterials Article Chromogenic Chemodosimeter Based on Capped Silica Particles to Detect Spermine and Spermidine Mariana Barros 1, Alejandro López-Carrasco 1, Pedro Amorós 2,* , Salvador Gil 1,3 , Pablo Gaviña 1,3 , Margarita Parra 1,3, Jamal El Haskouri 2, Maria Carmen Terencio 1,4 and Ana M. Costero 1,3,* 1 Instituto Interuniversitario de Investigación de Reconocimiento Molecular y Desarrollo Tecnológico (IDM), Universitad Politècnica de València, Universitat de València, Doctor Moliner 50, Burjassot, 46100 Valencia, Spain; [email protected] (M.B.); [email protected] (A.L.-C.); [email protected] (S.G.); [email protected] (P.G.); [email protected] (M.P.); [email protected] (M.C.T.) 2 Instituto de Ciencia de Materiales (ICMUV), Universitat de València, P.O. Box 2085, 46071 Valencia, Spain; [email protected] 3 CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), 28029 Madrid, Spain 4 Departamento de Farmacología, Universitat de València, Vicente Andrés Estellés S/n, Burjassot, 46100 Valencia, Spain * Correspondence: [email protected] (P.A.); [email protected] (A.M.C.) Abstract: A new hybrid organic–inorganic material for sensing spermine (Spm) and spermidine (Spd) has been prepared and characterized. The material is based on MCM-41 particles functionalized with an N-hydroxysuccinimide derivative and loaded with Rhodamine 6G. The cargo is kept inside the porous material due to the formation of a double layer of organic matter. The inner layer is covalently Citation: Barros, M.; López-Carrasco, bound to the silica particles, while the external layer is formed through hydrogen and hydrophobic A.; Amorós, P.; Gil, S.; Gaviña, P.; interactions.
    [Show full text]
  • United States Patent (19) (11 Patent Number: 4,866,206 Bey Et Al
    United States Patent (19) (11 Patent Number: 4,866,206 Bey et al. (45) Date of Patent: Sep. 12, 1989 54 2-HALOMETHYL DERIVATIVES OF 56) References Cited 2-AMNO ACDS U.S. PATENT DOCUMENTS (75) Inventors: Philippe Bey, Strasbourg; Michel 4,288,601 9/1981 Kollonitsch ................ o 562/561 Jung, Illkirch-Graffenstaden, both of 4,325,961 4/1982 Kolonitsch .... France 4,418,077 11/1983 Bey ................. 4,423,073 12/1983 Gerhart ...... .562/56 73) Assignee: Merrell Dow France et Cie, 4,439,619 3/1984 Bey ...................................... 562/561 Strasbourg, France 4,446,151 5/1984 Gerhart ............................... 562/56 Primary Examiner-Michael L. Shippen (21) Appl. No.: 148,806 Attorney, Agent, or Firm-Louis J. Wille (22 Filed: Jan. 27, 1988 (57) ABSTRACT 2-(Fluoromethyl or chloromethyl)-2,5-diaminopen Related U.S. Application Data tanoic acid, 2-(fluoromethyl or chloromethyl)-2,6- 60 Division of Ser. No. 392,052, Jun. 25, 1982, Pat, No. diaminohexanoic acid, and 2-fluoromethyl-2-amino-5- 4,743,691, which is a continuation-in-part of Ser. No. guanidinopentanoic acid, and certain derivatives 53,937, Jul. 2, 1979, abandoned, which is a continuation thereof, are inhibitors of ornithine decarboxylase. Meth of Ser. No. 814,765, Jul. 11, 1977, abandoned. ods of preparing the compounds and derivatives are 51l Int. Cl." .............................................. CO7C 99/00 also described. 52 U.S.C. .................................................... 562/561 58 Field of Search ................................ 562/561, 574 4 Claims, No Drawings 4,866,206 2 In its first composition of matter aspect, the invention 2-HALOMETHYL DERVATIVES OF 2-AMNO sought to be patented comprehends a pharmacologi ACDS cally active chemical compound of the formula: CROSS-REFERENCE TO RELATED I APPLICATION This is a division of application Ser.
    [Show full text]
  • Produces a Voltage-Dependent Flickery Block of Single NMDA Receptor Channels
    Neuroscience Letters, 144 (1992) 111-115 111 Elsevier Scientific Publishers Ireland Ltd. NSL 08933 The polyamine diaminodecane (DA-10) produces a voltage-dependent flickery block of single NMDA receptor channels David M. Rock a'l and Robert L. Macdonald b °Neuroseience Program and bDepartrnents of Neurology and Physiology, University of Michigan, Ann Arbor, MI (USA) (Received 31 January 1992; Revised version received 30 April 1992; Accepted 15 June 1992) Key words: N-Methyl-D-aspartate; Patch clamp; Single channel; Polyamine; Inverse agonist Receptor binding assays have shown that diaminodecane (DA-10) reduced binding of open channel blockers to the N-methyl-D-aspartate (NMDA) subtype of postsynaptic glutamate receptor through an interaction with the polyamine regulatory site. Because the action of DA-10 was opposite to that of the polyamine agonist spermine and was reversed by polyamine antagonists, DA-10 has been classified as an inverse agonist at the polyamine site. Using whole-cell voltage-clamp and single-channel recordings from cultured rat cortical neurons, we show that at negative holding potentials DA-10 (1-300 gM) reduced NMDA receptor whole cell current (IC50=34 pM) and produced a flickery block of NMDA single-channel currents. The flickery block of NMDA single channels was voltage-dependent and not reversed by the polyamine antagonist diethylenetriamine (DET). Potential mechanisms for the flickery block of NMDA single channel currents are discussed. The N-methyl-D-aspartate (NMDA) subtype of post- duction of NMDA receptor current by DA-10 was re- synaptic glutamate receptor has been shown to be im- versed by the polyamine antagonist DET [18].
    [Show full text]
  • Polyamines Potentiate Responses of N-Methyl-D-Aspartate Receptors
    Proc. Nadl. Acad. Sci. USA Vol. 87, pp. 9971-9974, December 1990 Neurobiology Polyamines potentiate responses of N-methyl-D-aspartate receptors expressed in Xenopus oocytes (glutamate/excitatory neurotransmitter/spermine/synaptic transmission) JAMES F. MCGURK, MICHAEL V. L. BENNETT, AND R. SUZANNE ZUKIN Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461 Contributed by Michael V. L. Bennett, September 19, 1990 ABSTRACT Glutamate, the major excitatory neurotrans- tiate the NMDA response. Moreover, spermine increased the mitter in the central nervous system, activates at least three affinity of the receptor for glycine without affecting its inter- types of channel-forming receptors defined by the selective action with NMDA (31, 32). agonists N-methyl-D-aspartate (NMDA), kainate, and quis- Polyamines have been shown to have a range of effects on qualate [or more selectively by a-amino-3-hydroxy-5-methyl- responses of glutamate receptors in hippocampal neurons 4-isoxazolepropionic acid (AMPA)]. Activation of the NMDA (33) and in Xenopus oocytes injected with messenger RNA receptor requires glycine as well as NMDA or glutamate. (mRNA) from rat and chicken brain (34). Spermine potenti- Recent studies have provided evidence that certain polyamines ated NMDA-induced currents in hippocampal neurons while potentiate the binding by NMDA receptors of glycine and the 1,10-diaminodecane decreased them; diethylenetriamine had open channel blocker MK-801. To determine whether poly- no action on NMDA responses but antagonized actions of amines alter channel opening, we examined their effects on rat both spermine and 1,10-diaminodecane, which may therefore brain glutamate receptors expressed in Xenopus oocytes.
    [Show full text]
  • Urinary Putrescine, Spermidine, and Spermine in Human Blood and Solid Cancers and in an Experimental Gastric Tumor of Rats
    (CANCER RESEARCH 36, 1320-1324, April 1976] Urinary Putrescine, Spermidine, and Spermine in Human Blood and Solid Cancers and in an Experimental Gastric Tumor of Rats Kelsuke Fujita,1 Toshiharu Nagatsu, Kazuhiro Maruta, Madoka Ito, Hideo Senba, and Kazuki Miki Institute for Comprehensive Medical Science, Fukita-Gakuen University School of Medicine, Toyoake, Aichi 470-11, Japan (K. F., K. M., M. I., H. S., K. MI, and Department of Biochemistry, School of Dentistry, Aichi-Gakuin University, Nagoya 464, Japan (T. N.J SUMMARY missions were observed. The patients had normal renal function, and patients with nephrosis or nephritis were not An improved method of assay of urinary polyamines (pu included, because it has been observed that urinary polya trescine, spermidine, and spermine) was applied to the mine concentrations rose in some but not all of the patients study of cancer patients and an experimental gastric tumor with nephrosis (K. Fujita, T. Nagatsu, K. Maruta, and M. Ito, of rats. Although total polyamines (putrescine, spermidine, unpublished results). and spermine) in urine of patients with blood and solid Experimental Stomach Cancer. For animal model studies cancers were significantly high , putrescine concentrations of tumors in the glandular stomach (6), 3.5 ml of NG2 also increased significantly and were shown to be of diag aqueous solution (2000 mg/liter) were administered to 20 nostic aid even in solid cancers. A significant increase in male Wistar rats through a stomach tube once a week for 42 putrescine was also noted in the urine of rats with experi weeks. Twenty control rats were given water freely.
    [Show full text]
  • Androgenic Control of Polyamine Concentrations in Rat Epididymis M
    Androgenic control of polyamine concentrations in rat epididymis M. A. de las Heras, S. I. Gonzalez and R. S. Calandra 1,2 1 Laboratorio de Esteroides, Instituto de Biologia y Medicina Experimental, Vuelta de Obligado 2490, 1428, Buenos Aires; and 2Cátedra de Endocrinología, Facultad de Ciencias Exactas, UNLP, La Plata, Argentina Summary. Unilateral orchidectomy resulted in a significant decrease in tissue content of putrescine and polyamines. However, no differences were detected when the results were expressed in terms of ng g \m=-\1tissue. At 48 h after bilateral orchidectomy, a signifi- cant decrease in putrescine content was observed, but spermidine and spermine content were unaffected. The observed decrease in putrescine was prevented by treatment with testosterone propionate, but neither spermidine nor spermine were affected. Bilateral orchidectomy resulted in a significant decrease in the tissue content of putrescine, spermidine and spermine after 7 days. Treatment with testosterone propionate increased the content of putrescine, spermidine and spermine in the epididymis by about 200%, 92% and 34%, respectively. When results were expressed as nmol g\m=-\1, a significant decrease after castration in putrescine and spermidine, but not in spermine, was observed. Treatment with testosterone propionate restored putrescine concentration, but had no effect on spermidine and spermine concentrations. In castrated rats treated with testosterone propionate, the anti-androgen flutamide abolished the effect of the androgen on putrescine and spermidine content, but there was no effect on spermine. Acetylputrescine was not detected in the epididymis, while acetylpolyamines were detected at much lower concentrations than polyamines. After bilateral orchidectomy there was a decrease in the tissue content of all acetylpolyamines and an increase in their tissue concentration.
    [Show full text]
  • An Improved High Performance Liquid Chromatographic Method for Identification and Quantization of Polyamines As Benzoylated Derivatives*
    American Journal of Analytical Chemistry, 2011, 2, 456-469 doi:10.4236/ajac.2011.24055 Published Online August 2011 (http://www.SciRP.org/journal/ajac) An Improved High Performance Liquid Chromatographic Method for Identification and Quantization of Polyamines * as Benzoylated Derivatives Rajat Sethi1#, Sai Raghuveer Chava2, Sajid Bashir2,3§, Mauro E. Castro2# 1Cardiovascular Research and Development Laboratory, Department of Pharmaceutical Sciences, Rangel College of Pharmacy, Texas A&M Health Science Center, Kingsville, USA 2Department of Chemistry, Texas A&M University-Kingsville, Kingsville, USA 3Chemical Biology Research Group (CBRG), 700 University Blvd, Kingsville, USA E-mail: #[email protected]; #[email protected] Received April 25, 2011; revised May 23, 2011; accepted June 23, 2011 Abstract A simple reversed phase high performance liquid chromatography (RP-HPLC) method was developed for the determination of putrescine, cadaverine and spermidine (a class of polyamines) in their benzoylated form from external known standards. In the optimization procedure, a number of parameters were exam- ined: 1) Solvent used in the extraction of standard polyamines (diethyl ether versus chloroform); 2) Sol- vent used in the elution of the polyamine (methanol versus acetonitrile); 3) Mode of derivatization and extraction step(s) (derivatization and extraction performed together versus derivatization and extraction performed separately); and 4) Other instrumental parameters (such as UV detection wavelength, gradient profiles). The advantages of
    [Show full text]