DOCSLIB.ORG

Tetrahydrobiopterin, L-Arginine and Vitamin C Act Synergistically To

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Tetrahydrobiopterin, L-Arginine and Vitamin C Act Synergistically To Tetrahydrobiopterin, L-Arginine and Vitamin C Act Synergistically to Decrease Oxidative Stress, Increase Nitric Oxide and Improve Blood Flow after Induction of Hindlimb Ischemia in the Rat Jinglian Yan, Guodong Tie, and Louis M Messina Department of Surgery, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America Nitric oxide (NO) derived from endothelial nitric oxide synthase (eNOS) is a potent vasodilator and signaling molecule that plays an essential role in vascular remodeling of collateral arteries and perfusion recovery in response to hindlimb ischemia. In ischemic conditions, decreased NO bioavailability was observed because of increased oxidative stress, decreased L-arginine and tetrahy- drobiopterin. This study tested the hypothesis that dietary cosupplementation with tetrahydrobiopterin (BH4), L-arginine, and vita- min C acts synergistically to decrease oxidative stress, increase nitric oxide and improve blood flow in response to acute hindlimb ischemia. Rats were fed normal chow, chow supplemented with BH4 or L-arginine (alone or in combination) or chow supple- mented with BH4 + L-arginine + vitamin C for 1 wk before induction of unilateral hindlimb ischemia. Cosupplementation with BH4 + 2+ L-arginine resulted in greater eNOS expression, Ca -dependent NOS activity and NO concentration in gastrocnemius from the is- chemic hindlimb, as well as greater recovery of foot perfusion and more collateral artery enlargement than did rats receiving ei- ther agent separately. The addition of vitamin C to the BH4 + L-arginine regimen did further increase these dependent variables, although only the increase in eNOS expression reached statistical significances. In addition, rats given all three supplements demonstrated significantly less Ca2+-independent activity, less nitrotyrosine accumulation, greater glutathione:glutathione disul- fide (GSH:GSSG) ratio and less gastrocnemius muscle necrosis, on both macroscopic and microscopic levels. In conclusion, co- supplementation with BH4 + L-arginine + vitamin C significantly increased vascular perfusion after hindlimb ischemia by increas- ing eNOS activity and reducing oxidative stress and tissue necrosis. Oral cosupplementation of L-arginine, BH4 and vitamin C holds promise as a biological therapy to induce collateral artery enlargement. Online address: http://www.molmed.org doi: 10.2119/molmed.2011.00103 INTRODUCTION loss of eNOS-derived NO production At least two characteristics of eNOS Endothelial dysfunction is a hallmark (that is, functional inactivation of eNOS) render it susceptible to oxidative stress. of peripheral artery disease (PAD) (1). and inactivation of NO by a superoxide First, eNOS transcription, posttransla- – Central to the development of endothelial anion (O2 ) to form peroxynitrite tional modification and trafficking to the dysfunction, regardless of its cause, is a (OONO–) (2,3). It is likely that all three caveolae are attenuated by the accumula- reduction in the bioavailability of nitric mechanisms contribute to the endothelial tion of reactive oxygen species (ROS) oxide (NO) derived from endothelial ni- dysfunction characteristic of PAD because within the endothelial cell (4). Second, the tric oxide synthase (eNOS). Three funda- increased oxidative stress is a common eNOS cofactor tetrahydrobiopterin (BH4) mental mechanisms can compromise NO antecedent in the pathogenesis of this dis- is highly susceptible to oxidation (5). BH4 bioavailability: loss of eNOS expression, ease and can reduce NO bioavailability. maintains eNOS in its functional dimeric form; in the absence of BH4, eNOS be- comes uncoupled so that the electron flux is diverted away from the L-arginine bind- Address correspondence to Louis M Messina, Department of Surgery, University of Massa- ing site and instead reduces molecular chusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655. Phone: 508-856- – oxygen, generating O2 (6). This circum- 5599; Fax: 508-856-8329; E-mail: [email protected]. stance initiates a vicious cycle, wherein Submitted March 22, 2011; Accepted for publication February 21, 2012; Epub – eNOS catalytic activity produces O2 , not www.molmed.org) ahead of print February 24, 2012. NO, worsening existent oxidative stress. These molecular characteristics of eNOS predict that several therapeutic options might prove effective for the 676 | YAN ET AL. | MOL MED 18:676-684, 2012 RESEARCH ARTICLE treatment of PAD, namely dietary sup- respectively. This action would enhance Preparation plementation with an antioxidant, or eNOS-derived NO production and, by Severe ischemia was induced in the – with the eNOS substrate L-arginine, or quenching existent O2 , reduce NO inac- left hindlimb. The femoral artery was lig- – with the eNOS cofactor BH4. Vitamin C, tivation by its reaction with O2 . ated between the inguinal ligament and or L-ascorbic acid, is a potent antioxidant In our previous work (19), we observed popliteal fossa, and the ligated section and has been shown to preserve BH4 decreased eNOS expression, decreased and its branches were excised. This pro- levels and enhance endothelial NO pro- bioavailable NO and increased oxidative cedure was carried out under anesthesia duction in vitro (7). ONOO– reacts with stress in hindlimb ischemic rats, and oral with 2% isofluorane. The untreated right BH4 6–10 times faster when in the pres- supplementation of BH4 increased the hindlimb served as an internal control ence of ascorbate. The intermediate prod- beneficial effect of eNOS gene transfer. for each rat. An additional group of uct of the reaction between ONOO– and The goal of this study was to test the hy- sham-operated rats were also used for BH4 is the trihydrobiopterin radical pothesis that combined dietary supple- selected assays. These rats underwent • (BH3 ), which is also reduced back to mentation with BH4, L-arginine and vita- isolation of the femoral artery in the left BH4 by ascorbate. Thus, ascorbate does min C will act synergistically to improve hindlimb under 2% isofluorane anesthe- not protect BH4 from oxidation but hindlimb perfusion recovery and preser- sia, but the artery was left intact. rather recycles the BH3 radical back to vation of tissue integrity in response to BH4 (8). Vitamin C levels are low in PAD severe hindlimb ischemia. To this end, we Study Design patients (9), and acute (10) or short-term generated severe hindlimb ischemia in All rats were fed standard chow in (11) vitamin C supplementation reduces the rat by means of femoral artery exci- powder form and water ad libitum PAD symptoms; however, cross-sectional sion. Measured dependent variables in- (Deans Feeds, Redwood City, CA, USA). epidemiological surveys have failed to cluded gastrocnemius muscle eNOS ex- Animals were randomly selected to re- find a clear link between long-term vita- pression and activity, hindlimb laser ceive normal chow (control), chow with min C intake and PAD symptoms or dis- Doppler perfusion and collateral artery a single added supplement (BH4 or ease progression (12,13). L-arginine sup- enlargement, and gastrocnemius nitroty- L-arginine), chow supplemented with plementation showed exciting promise in rosine accumulation and tissue necrosis. BH4 + L-arginine or chow supplemented short-term studies of PAD (14,15), but with BH4 + L-arginine + L-ascorbic acid. this effect was not observed in a subse- MATERIALS AND METHODS Dietary supplementation was com- quent long-term study by the same group menced 7 d before the induction of (16). BH4 improves eNOS- dependent va- Materials hindlimb ischemia and was continued sodilation in long-term smokers and pa- Dietary supplements included the fol- until sacrifice of the animal. Chow was tients with type 2 diabetes, conditions as- lowing: BH4 (10 mg/kg/d; Schircks Lab- replaced every 2 d. The time of sacrifice sociated with increased oxidative stress oratories, Jonas, Switzerland); L-arginine, varied with the measured endpoint (17,18). To our knowledge, BH4 has not provided as L-arginine α-ketoglutarate under consideration, as described below. been specifically evaluated as a therapeu- (hereafter L-arginine; 88.5 mg/kg/d; tic modality in PAD. Body Tech, North Bergen, NJ, USA); and Western Blotting An important gap in our understand- L-ascorbic acid (that is, vitamin C; 88.5 Rats were sacrificed 14 d after induc- ing of BH4, L-arginine and L-ascorbic mg/kg/d, Sigma-Aldrich, St. Louis, MO, tion of ischemia for measurement of acid in the prevention and treatment of USA). The dose of tetrahydrobiopterin gastrocnemius muscle eNOS, phosphory- PAD is the potential synergistic effect of was selected on the basis of a published lated eNOS (p-eNOS) and nitrotyrosine combined therapy, and there is convinc- report of its use in rats (35). And the dose expression. The timing of death was se- ing evidence to suggest that such an ap- of L-arginine and vitamin C was on the lected on the basis of previous work that proach would prove successful. For ex- basis of their clinical dose in patients. demonstrated maximal postischemic ample, supplementation with L-arginine change in these variables at this time (19). alone might prove deleterious in the face Animals Samples were homogenized in liquid ni- of endothelial oxidative stress inasmuch All protocols were approved by the trogen and transferred to NP-40 lysis as the resultant increase in eNOS cat- Institutional Animal Care and Use Com- buffer, comprised of 50 mmol/L HEPES – alytic activity might generate O2 , not mittee at the University
Load more

Recommended publications
  • (12) United States Patent (10) Patent No.: US 7.803,838 B2 Davis Et Al
    USOO7803838B2 (12) United States Patent (10) Patent No.: US 7.803,838 B2 Davis et al. (45) Date of Patent: Sep. 28, 2010 (54) COMPOSITIONS COMPRISING NEBIVOLOL 2002fO169134 A1 11/2002 Davis 2002/0177586 A1 11/2002 Egan et al. (75) Inventors: Eric Davis, Morgantown, WV (US); 2002/0183305 A1 12/2002 Davis et al. John O'Donnell, Morgantown, WV 2002/0183317 A1 12/2002 Wagle et al. (US); Peter Bottini, Morgantown, WV 2002/0183365 A1 12/2002 Wagle et al. (US) 2002/0192203 A1 12, 2002 Cho 2003, OOO4194 A1 1, 2003 Gall (73) Assignee: Forest Laboratories Holdings Limited 2003, OO13699 A1 1/2003 Davis et al. (BM) 2003/0027820 A1 2, 2003 Gall (*) Notice: Subject to any disclaimer, the term of this 2003.0053981 A1 3/2003 Davis et al. patent is extended or adjusted under 35 2003, OO60489 A1 3/2003 Buckingham U.S.C. 154(b) by 455 days. 2003, OO69221 A1 4/2003 Kosoglou et al. 2003/0078190 A1* 4/2003 Weinberg ...................... 514f1 (21) Appl. No.: 11/141,235 2003/0078517 A1 4/2003 Kensey 2003/01 19428 A1 6/2003 Davis et al. (22) Filed: May 31, 2005 2003/01 19757 A1 6/2003 Davis 2003/01 19796 A1 6/2003 Strony (65) Prior Publication Data 2003.01.19808 A1 6/2003 LeBeaut et al. US 2005/027281.0 A1 Dec. 8, 2005 2003.01.19809 A1 6/2003 Davis 2003,0162824 A1 8, 2003 Krul Related U.S. Application Data 2003/0175344 A1 9, 2003 Waldet al. (60) Provisional application No. 60/577,423, filed on Jun.
    [Show full text]
  • Tetrahydrobiopterin Loading Test in Hyperphenylalaninemia
    003 1-399819113005-0435$03.00/0 PEDIATRIC RESEARCH Vol. 30, No. 5, 1991 Copyright 0 199 1 International Pediatric Research Foundation, Inc. Pr~ntc.d in U.S. A Tetrahydrobiopterin Loading Test in Hyperphenylalaninemia ALBERT0 PONZONE, ORNELLA GUARDAMAGNA, SILVIO FERRARIS, GIOVANNI B. FERRERO, IRMA DIANZANI, AND RICHARD G. H. COTTON InstiflifeofPediatric Clinic(A.P., O.G., S.F., G.B.F., I.D.], University of Torino, 10126 Torino, Italy and Olive Miller Laboratory [R.G.H.C.],Murdoch Institute, Royal Children's Hospital, Vicroria,Australia 3052 ABSTRACT. Some cases of primary hyperphenylalanine- PKU to describe some cases clinically unresponsive to a Phe- mia are not caused by the lack of phenylalanine hydroxyl- restricted diet and later shown to be due to BH4 deficiency ase, but by the lack of its cofactor tetrahydrobiopterin. ( 1-4). These patients are not clinically responsive to a phenylal- By analyzing all the essential components of the complex anine-restricted diet, but need specific substitution therapy. hydroxylation system of aromatic amino acids, it became appar- Thus, it became necessary to examine all newborns ent that a defect in the BH4 recycling enzyme DHPR (EC screened as positive with the Guthrie test for tetrahydro- 1.66.99.7) and two defects in BH4 synthetic pathway enzymes, biopterin deficiency. Methods based on urinary pterin or guanosine triphosphate cyclohydrolase I (EC 3.5.4.16) and 6- on specific enzyme activity measurements are limited in PPH4S, may lead to cofactor deficiency resulting in HPA and in their availability, and the simplest method, based on the impaired production of dopamine and serotonin (5-7).
    [Show full text]
  • Coronary Microvascular Dysfunction in CAD: Consequences and Potential Therapeutic Applications
    4 Coronary Microvascular Dysfunction in CAD: Consequences and Potential Therapeutic Applications Alan N. Beneze1, Jeffrey M. Gold4 and Betsy B. Dokken1,2,3 1University of Arizona College of Medicine 2University of Arizona Department of Medicine, Section of Endocrinology 3University of Arizona Sarver Heart Center 4Inpatient Physicians Consultants, Tucson, Arizona USA 1. Introduction Substantial research and clinical effort has been directed toward the understanding, identification and management of coronary artery disease (CAD). As a result, the processes of cholesterol accumulation and inflammation that lead to large vessel occlusions have been fully elucidated. In contrast to those with CAD, many patients have symptoms of angina and reductions in coronary flow reserve despite normal coronary angiography of the large epicardial arteries. In this situation the vessels that limit flow to myocardium are the more distal epicardial prearterioles and intramyocardial arterioles – vessels typically too small to be directly visualized by conventional coronary angiography. These vessels comprise the coronary microcirculation. Coronary microvascular dysfunction (CMVD), in contrast to CAD, continues to be poorly understood and difficult to manage. In addition, the presence of CMVD can be a confounding factor in the management of patients with CAD. 2. Anatomy and physiology of the coronary microcirculation The coronary arterial network is generally divided into three sequential morphological zones. The large epicardial coronary arteries decrease in diameter from 2-5 to 500 microns as they branch off of the aorta and travel distally along the epicardium. Distal to the large coronary arteries are epicardial pre-arterioles that decrease in diameter from 500 to 100 microns. Finally, the pre-arterioles give rise to intramyocardial arterioles that measure 100 microns or less in diameter.
    [Show full text]
  • Example of How Amehsi Specification Indicators Can Be Mapped to Health
    Example of how Amehsi Specification Indicators can be Mapped to Health Conditions and Health Statuses The information presented here may be covered by copyrights and patents Some of the Amehsi Factors which can be alleviated using Amehsi Specification Recommendations and Demise Oncology Leukemia Lymphoma HIV Information. This document may be protected by copyrights and patents Choline Deficiency or Circumstantial Choline Deficiency from upregulated Choline Kinase Pathway or Kennedy Pathway Factors Causal Causal Causal Causal Causal Homocysteine Required as Symptom, Correlated and Incipiently Causal, inhibits PEMT Required Causal Causal Causal S-Adenosyl Homocysteine Downregulat Required as Symptom, Correlated and Incipiently Causal, inhibits PEMT Required Causal ed PEMT Causal Trimethylamine-N-Oxide Causal, inhibits PEMT Causal Causal Causal Incipient Enabler Choline Kinase Upregulation Causal Required Required uNOS Required Required as both PEMT1 or PEMT2 since Diagnostic Assay sometimes does not report if one of these is inhibited while the other is not. PEMT produces a Monomethylethanolamine that Phosphatidylethanolamine deteriorates PCBs, Dioxins, Aryl Methyltransferase Downregulation Cyclic Hydrocarbons, Alkyl Halides, other Carcinogens and produces Serine Proteases that catabolize Amino acids to thier most basic structures, resulting in purified cellular environment and embryonic Causal cellular plasticity Required Required Required Inducible Nitric Oxide Synthase, Required, inhibits PEMT and upregulated Choline kinase, as well as
    [Show full text]
  • Enos-Uncoupling in Age-Related Erectile Dysfunction
    International Journal of Impotence Research (2011) 23, 43–48 & 2011 Macmillan Publishers Limited All rights reserved 0955-9930/11 www.nature.com/ijir ORIGINAL ARTICLE eNOS-uncoupling in age-related erectile dysfunction JM Johnson, TJ Bivalacqua, GA Lagoda, AL Burnett and B Musicki Department of Urology, The Johns Hopkins University, Baltimore, MD, USA Aging is associated with ED. Although age-related ED is attributed largely to increased oxidative stress and endothelial dysfunction in the penis, the molecular mechanisms underlying this effect are not fully defined. We evaluated whether endothelial nitric oxide synthase (eNOS) uncoupling in the aged rat penis is a contributing mechanism. Correlatively, we evaluated the effect of replacement with eNOS cofactor tetrahydrobiopterin (BH4) on erectile function in the aged rats. Male Fischer 344 ‘young’ (4-month-old) and ‘aged’ (19-month-old) rats were treated with a BH4 precursor sepiapterin (10 mg/kg intraperitoneally) or vehicle for 4 days. After 1-day washout, erectile function was assessed in response to electrical stimulation of the cavernous nerve. Endothelial dysfunction (eNOS uncoupling) and oxidative stress (thiobarbituric acid reactive substances, TBARS) were measured by conducting western blot in penes samples. Erectile response was significantly reduced in aged rats, whereas eNOS uncoupling and TBARS production were significantly increased in the aged rat penis compared with young rats. Sepiapterin significantly improved erectile response in aged rats and prevented increase in TBARS
    [Show full text]
  • Effects of Nitric Oxide Synthase Inhibitors on Equine and Bovine Follicular Dynamics and Steroidogenesis
    Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 2001 Effects of Nitric Oxide Synthase Inhibitors on Equine and Bovine Follicular Dynamics and Steroidogenesis. Carlos Roberto fontes Pinto Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Pinto, Carlos Roberto fontes, "Effects of Nitric Oxide Synthase Inhibitors on Equine and Bovine Follicular Dynamics and Steroidogenesis." (2001). LSU Historical Dissertations and Theses. 430. https://digitalcommons.lsu.edu/gradschool_disstheses/430 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps.
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 6,537,992 B2 Parker (45) Date of Patent: Mar
    USOO6537992B2 (12) United States Patent (10) Patent No.: US 6,537,992 B2 Parker (45) Date of Patent: Mar. 25, 2003 (54) REGULATION OF ORGANIC NITRATE Erik Stroes, et al., “Tetrahydrobiopterin Restores Endothe TOLERANCE lial Function in Hypercholesterolemia', J. Clin. Invest., vol. 99, No. 1, Jan., 1997, pp. 41–46. (75) Inventor: John D. Parker, 15 Oakly Place, Jørn Bech Laursen, et al., “Nitrate Tolerance Impairs Nitric Toronto, Ontario (CA), M2P 2G3 Oxide-Mediated Vasodilation in Vivo”, Cardiovascular Research, vol. 31, (1996) pp. 814-819. (73) Assignee: John D. Parker (CA) Chao Han, et al., “Pharmacokinetics of Nitroglycerin and Its * Y NotOtice: Subjubject to anyy disclaimer,disclai theh term off thisthi Four Metabolites During Nitroglycerin Transdermal Admin patent is extended or adjusted under 35 istration', Biopharmaceutics & Drug Disposition, Vol. 15, U.S.C. 154(b) by 0 days. (1994) pp. 179–183. Georgette M. Buga, et al., “Negative Feedback Regulation of Endothelial Cell Function by Nitric Oxide', Circulation (21) Appl. No.: 09/754,196 Research, vol. 73, No. 5, Nov., 1993, pp. 808–812. (22) Filed: Jan. 5, 2001 Frank W. Lee, et al., “Pharmacokinetics and Pharmacody namics of Nitroglycerin and Its Dinitrate Metabolites in (65) Prior Publication Data Conscious Dogs: Intravenous Infusion Studies”, J. of Pharm. US 2002/009 1126 A1 Jul. 11, 2002 and Biopharm., vol. 21, No. 5, (1993) pp. 533–550. Walter E. Haefeli, et al., “Comparison of Vasodilatory (51) Int. Cl." .............................................. A61K 31f495 Responses to Nitroglycerin and its Dinitrate Metabolites in (52) U.S. Cl. ....................................................... 514/249 Human Veins”, Clin. Pharmacol. Ther., vol. 52, No.
    [Show full text]
  • Effects of Rosiglitazone on Nitroglycerin
    EFFECTS OF ROSIGLITAZONE ON NITROGLYCERIN- INDUCED ENDOTHELIAL DYSFUNCTION by Kumar Perampaladas B.Sc. A thesis submitted in conformity with the requirements for the degree of Master of Science Graduate Department of Pharmacology and Toxicology University of Toronto Supervisor: John D. Parker, MD, FRCP(C) © Copyright by Kumar Perampaladas (2010) Effects of Rosiglitazone on Nitroglycerin-Induced Endothelial Dysfunction Kumar Perampaladas, Master of Science, 2010 Graduate Department of Pharmacology and Toxicology, University of Toronto ABSTRACT Sustained nitroglycerin (GTN) therapy impairs endothelial function in healthy volunteers and patients with cardiovascular disease, caused by an increase in vascular oxidative stress. This study aims to estimate the effect of rosiglitazone on vascular endothelial function in healthy volunteers continuously dosed to transdermal GTN (0.6mg/hr) for 7 days. To assess endothelial function, forearm blood flow was measured by venous occlusion strain-gauge plethysmography in response to intra-brachial infusions of acetylcholine. GTN-treated subjects experienced significant attenuation of endothelium-dependent responses to acetylcholine (p<0.05; compared to placebo), but was reversed with vitamin C (p=ns; compared to placebo). Endothelium-dependent responses to acetylcholine were blunted in groups randomized to rosiglitazone alone (p<0.05; compared to placebo) and rosiglitazone + GTN (p<0.05 compared to placebo). Interestingly, this effect was not modified by vitamin C. In conclusion, rosiglitazone impairs endothelial function and concurrent therapy with rosiglitazone does not attenuate the adverse effects of transdermal GTN on the vasculature. ii ACKNOWLEDGEMENTS First and foremost, I would like to thank my supervisor Dr. John Parker for his continuous support during my Master’s Program. Dr.
    [Show full text]
  • Tetrahydrobiopterin: a Novel Antihypertensive Therapy
    Journal of Human Hypertension (2008) 22, 401–407 & 2008 Nature Publishing Group All rights reserved 0950-9240/08 $30.00 www.nature.com/jhh ORIGINAL ARTICLE Tetrahydrobiopterin: a novel antihypertensive therapy M Porkert1, S Sher1, U Reddy1, F Cheema1, C Niessner1, P Kolm2, DP Jones3, C Hooper4, WR Taylor1, D Harrison1 and AA Quyyumi1 1Division of Cardiology, Emory University, Atlanta, GA, USA; 2Christiana Care Center for Outcomes Research, Newark, DE, USA; 3General Clinical Research Center, Emory University, Atlanta, GA, USA and 4Centers for Disease Control, Atlanta, GA, USA Tetrahydrobiopterin (BH4) is a cofactor for the nitric after 5 weeks and persisted for the 8-week study period. oxide (NO) synthase enzymes, such that its insuffi- Study 2: subjects given 400 mg BH4 had decreased ciency results in uncoupling of the enzyme, leading to systolic (P ¼ 0.03) and mean BP (P ¼ 0.04), with a peak release of superoxide rather than NO in disease decline of 16±19 mm Hg (P ¼ 0.04) at 3 weeks. BP states, including hypertension. We hypothesized that returned to baseline 4 weeks after discontinuation. oral BH4 will reduce arterial blood pressure (BP) and Significant improvement in endothelial function was improve endothelial function in hypertensive subjects. observed in Study 1 subjects and those receiving Oral BH4 was given to subjects with poorly controlled 400 mg BH4. There was no significant change in subjects hypertension (BP 4135/85 mm Hg) and weekly measure- given the 200 mg dose. This pilot investigation indicates ments of BP and endothelial function made. In Study 1, 5 that oral BH4 at a daily dose of 400 mg or higher has À1 À1 or 10 mg kg day of BH4 (n ¼ 8) was administered a significant and sustained antihypertensive effect orally for 8 weeks, and in Study 2, 200 and 400 mg of in subjects with poorly controlled hypertension, an BH4 (n ¼ 16) was given in divided doses for 4 weeks.
    [Show full text]
  • Changes in the Dimeric State of Neuronal Nitric Oxide Synthase
    Changes in the Dimeric State of Neuronal Nitric Oxide Synthase Affect the Kinetics of Secretagogue-Induced Insulin Response Anne-Dominique Lajoix,1,2 Martine Pugnie`re,2 Franc¸oise Roquet,2 Jean-Claude Mani,2 Samuel Dietz,1,2 Nathalie Linck,2 Fleur Faurie,2 Ge´rard Ribes,2 Pierre Petit,2 and Rene´ Gross2 2ϩ We previously showed that pancreatic ␤-cells express a Ca -calmodulin–independent inducible NOS (iNOS) (1). As neuronal isoform of nitric oxide synthase (nNOS) that homodimers (2), NOSs produce NO through the transfer of controls insulin secretion by exerting two enzymatic NADPH-derived electrons from the reductase domain to the activities: nitric oxide (NO) production and cytochrome heme of the adjacent oxygenase domain, so that the heme c reductase activity. We now bring evidence that two iron binds O2 and catalyzes the mono-oxygenation of the inhibitors of nNOS, N-␻-nitro-L-arginine methyl ester substrate arginine. Accordingly, different classes of NOS (L-NAME) and 7-nitroindazole (7-NI), increase glucose- inhibitors have been developed to assess the functional role induced insulin secretion but affect ␤-cell function dif- of these enzymes and include substrate-based inhibitors such ferently. In the presence of L-NAME, insulin response is monophasic, whereas 7-NI preserves the normal bipha- as arginine analogs (3–5) and imidazole derivatives (6), sic secretory pattern. In addition, the alterations of which compete with the substrate binding, flavoprotein (7), ␤-cell functional response induced by the inhibitors also calmodulin inhibitors (8), and finally pterin antagonists such differ by their sensitivity to a substitutive treatment as indazole agents (9).
    [Show full text]
  • Decreased Expression of Intestinal P-Glycoprotein Increase the Analgesic Effects of Oral Morphine in a Streptozotocin-Induced Diabetic Mouse Model
    Drug Metabolism and Pharmacokinetics (DMPK) Advance Publication by J-STAGE Received; June 2, 2011 Published online; August 30, 2011 Accepted; August 12, 2011 doi; 10.2133/dmpk.DMPK-11-RG-051 Decreased expression of intestinal P-glycoprotein increase the analgesic effects of oral morphine in a streptozotocin-induced diabetic mouse model Ayaka Nawa1, Wakako Fujita-Hamabe1, Shiroh Kishioka2, and Shogo Tokuyama1＊ 1 Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586, Japan 2 Department of Pharmacology, Wakayama Medical University, 811-1 Kimiidera, Wakayama 641-8059, Japan 1 Copyright C 2011 by the Japanese Society for the Study of Xenobiotics (JSSX) Drug Metabolism and Pharmacokinetics (DMPK) Advance Publication by J-STAGE Running title page: P-gp increase the analgesic effects of oral morphine *Correspondence to: Shogo Tokuyama Ph. D. Department of Clinical Pharmacy, School of Pharmaceutical Sciences Kobe Gakuin University 1-1-3 Minatojima, Chuo-ku, Kobe 650-8586, Japan Tel./Fax: +81-78-974-4780 Email: [email protected] The number of text pages; 31 The number of figures; 7 2 Drug Metabolism and Pharmacokinetics (DMPK) Advance Publication by J-STAGE SUMMARY Morphine is one of the strongest analgesics and commonly used for the treatment of chronic pain. The pharmacokinetic properties of morphine are, in part, modulated by P-glycoprotein (P-gp). We have previously reported that intestinal P-gp expression levels are influenced via the activation of inducible nitric oxide synthase (iNOS) in streptozotocin (STZ)-induced diabetic mice. Herein, we examined the analgesic effects of orally administrated morphine and its pharmacokinetic properties under diabetic conditions, specifically we focusing on the involvement of intestinal P-gp in a type 1 diabetic mouse model.
    [Show full text]
  • (12) Patent Application Publication (10) Pub. No.: US 2013/0336945 A1 Rustomjee Et Al
    US 2013 0336945A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2013/0336945 A1 Rustomjee et al. (43) Pub. Date: Dec. 19, 2013 (54) STABLE COMPOSITIONS OF (30) Foreign Application Priority Data TETRAHYDROBOPTERN Mar. 1, 2011 (IN) ........................... 573/MUM/2011 (71) Applicants: Maharukh Tehmasp Rustomjee, Mumbai (IN); Anilkumar Surendrakumar Gandhi, Mumbai (IN) Publication Classification (72) Inventors: Maharukh Tehmasp Rustomjee, (51) Int. Cl. Mumbai (IN); Anilkumar A 6LX3/59 (2006.01) Surendrakumar Gandhi, Mumbai (IN) (52) U.S. Cl. (73) Assignee: RUBICON RESEARCH PRIVATE CPC .................................... A6 IK3I/519 (2013.01) LIMITED, MUNBAI (IN) USPC .......................................... 424/94.1: 514/249 (21) Appl. No.: 14/002,313 (57) ABSTRACT (22) PCT Filed: Mar. 1, 2013 The present invention relates to stable pharmaceutical com (86). PCT No.: PCT/IB12/SO959 positions of tetrahydrobiopterin and processes for producing Such compositions. Particularly the present invention relates S371 (c)(1), to stable pharmaceutical compositions comprising tetrahy (2), (4) Date: Aug. 29, 2013 drobiopterin and at least one stabilizing agent. US 2013/0336945 A1 Dec. 19, 2013 STABLE COMPOSITIONS OF unpalatable. Further the strict regimen of dietary protein is TETRAHYDROBOPTERN practically impossible for patients of all ages to adhere to in daily life. FIELD OF THE INVENTION 0006 Thus there remains a need to obviate the dietary restrictions and replace or Supplement the same with oral 0001. The present invention relates to stable compositions treatment by providing an oral composition of tetrahydro of tetrahydrobiopterin and processes for producing Such com biopterin. positions. Particularly the present invention relates to stable 0007 Further BH4-responsive PAH deficiency has also compositions comprising sapropterin or pharmaceutically been diagnosed as a variant of hyperphenylalaninemia or acceptable salts thereof and at least one stabilizing agent.
    [Show full text]