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Dos Santos DR, Fiais GA, Oliveira HA, Ribas TB, Souza RO, Tsosura TVS, Matsushita DH, Ervolino E, Dornelles RCM, Nakamune ACDMS, Chaves-Neto AH. Assessment of redox state and biochemical parameters of salivary glands in rats treated with anti-obesity drug sibutramine hydrochloride. Clin Oral Investig 2022; 26:5833-5846. [PMID: 35556176 DOI: 10.1007/s00784-022-04539-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 05/04/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To investigate the effects of anti-obesity drug sibutramine hydrochloride (SB) on redox state and biochemical parameters in the salivary glands. MATERIALS AND METHODS Adult male Wistar rats were randomly divided into the following groups (n = 8 per group): control rats treated with vehicle (C) and rats treated with SB (10 mg/kg/day) by intragastric gavage for 28 days. The parotid (PG) and submandibular (SMG) glands were processed using histomorphometric analysis, and total protein, amylase, mucin, and oxidative damage to lipids were determined by measuring the formation of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), uric acid (UA), total glutathione (tGSH), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and AKT phosphorylation. RESULTS SB decreased the acinar area, and increased the stromal area in PG, while no effect on the morphometric parameters was observed in SMG. SB also increased oxidative damage to lipids (TBARs). The SB group showed lower total protein, amylase, TAC, UA, tGSH, SOD, CAT, and GPx than the C group in PG, while in SMG, SB decreased total protein, mucin, tGSH, SOD, CAT, and GPx. However, increased AKT phosphorylation observed in both salivary glands suggests that SB exerts low-intensity oxidative stress. CONCLUSIONS SB impaired enzymatic and non-enzymatic antioxidant defenses in the salivary glands of rats. CLINICAL RELEVANCE Chronic treatment with SB could mitigate salivary gland dysfunction due to disturbance of redox state.
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Affiliation(s)
- Damáris Raissa Dos Santos
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil.,Programa de Pós-Graduação Multicêntrico Em Ciências Fisiológicas-SBFIs, Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Aracatuba, São Paulo, Brazil
| | - Gabriela Alice Fiais
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil.,Programa de Pós-Graduação Multicêntrico Em Ciências Fisiológicas-SBFIs, Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Aracatuba, São Paulo, Brazil
| | - Henrique Arnaldo Oliveira
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil
| | - Tayná Buffulin Ribas
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil
| | - Rayne Oliveira Souza
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil
| | - Thaís Verônica Saori Tsosura
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil.,Programa de Pós-Graduação Multicêntrico Em Ciências Fisiológicas-SBFIs, Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Aracatuba, São Paulo, Brazil
| | - Doris Hissako Matsushita
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil.,Programa de Pós-Graduação Multicêntrico Em Ciências Fisiológicas-SBFIs, Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Aracatuba, São Paulo, Brazil
| | - Edilson Ervolino
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil
| | - Rita Cássia Menegati Dornelles
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil.,Programa de Pós-Graduação Multicêntrico Em Ciências Fisiológicas-SBFIs, Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Aracatuba, São Paulo, Brazil
| | - Ana Cláudia de Melo Stevanato Nakamune
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil.,Programa de Pós-Graduação Multicêntrico Em Ciências Fisiológicas-SBFIs, Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Aracatuba, São Paulo, Brazil
| | - Antonio Hernandes Chaves-Neto
- Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Rodovia Marechal Rondon, km 527/528, Aracatuba, São Paulo, CEP 16018-805, Brazil. .,Programa de Pós-Graduação Multicêntrico Em Ciências Fisiológicas-SBFIs, Department of Basic Sciences, School of Dentistry of Araçatuba- UNESP - Universidade Estadual Paulista, Aracatuba, São Paulo, Brazil.
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Van Daele M, Cooper SL, Pannucci P, Wragg ES, March J, de Jong I, Woolard J. Monitoring haemodynamic changes in rodent models to better inform safety pharmacology: Novel insights from in vivo studies and waveform analysis. JRSM Cardiovasc Dis 2022; 11:20480040221092893. [PMID: 35646334 PMCID: PMC9133998 DOI: 10.1177/20480040221092893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/21/2022] [Accepted: 03/22/2022] [Indexed: 01/13/2023] Open
Abstract
Animal models are essential for assessing cardiovascular responses to novel therapeutics. Cardiovascular safety liabilities represent a leading cause of drug attrition and better preclinical measurements are essential to predict drug-related toxicities. Presently, radiotelemetric approaches recording blood pressure are routinely used in preclinical in vivo haemodynamic assessments, providing valuable information on therapy-associated cardiovascular effects. Nonetheless, this technique is chiefly limited to the monitoring of blood pressure and heart rate alone. Alongside these measurements, Doppler flowmetry can provide additional information on the vasculature by simultaneously measuring changes in blood flow in multiple different regional vascular beds. However, due to the time-consuming and expensive nature of this approach, it is not widely used in the industry. Currently, analysis of waveform data obtained from telemetry and Doppler flowmetry typically examines averages or peak values of waveforms. Subtle changes in the morphology and variability of physiological waveforms have previously been shown to be early markers of toxicity and pathology. Therefore, a detailed analysis of pressure and flowmetry waveforms could enhance the understanding of toxicological mechanisms and the ability to translate these preclinical observations to clinical outcomes. In this review, we give an overview of the different approaches to monitor the effects of drugs on cardiovascular parameters (particularly regional blood flow, heart rate and blood pressure) and suggest that further development of waveform analysis could enhance our understanding of safety pharmacology, providing valuable information without increasing the number of in vivo studies needed.
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Affiliation(s)
- Marieke Van Daele
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Midlands, UK
| | - Samantha L Cooper
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Midlands, UK
| | - Patrizia Pannucci
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Midlands, UK
| | - Edward S Wragg
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Midlands, UK
| | - Julie March
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
| | - Iwan de Jong
- Maastricht Instruments BV, Maastricht University, Maastricht, The Netherlands
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Midlands, UK
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3
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Active pharmaceutical contaminants in dietary supplements: A tier-based risk assessment approach. Regul Toxicol Pharmacol 2021; 123:104955. [PMID: 34022259 DOI: 10.1016/j.yrtph.2021.104955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 04/10/2021] [Accepted: 05/06/2021] [Indexed: 11/23/2022]
Abstract
The presence of active pharmaceutical ingredients (APIs) in adulterated or contaminated dietary supplements is a current product safety concern. Since there are limited guidelines, and no published consensus methods, we developed a tier-based framework incorporating typical lines of evidence for determining the human health risk associated with APIs in dietary supplements. Specifically, the tiered approach outlines hazard identification and decision to test for APIs in products based on criteria for likelihood of contamination or adulteration, and evaluation of manufacturer production standards. For products with detectable levels of APIs, a variety of default approaches, including the use of fraction of the therapeutic dose and the threshold of toxicological concern (TTC), as well as health-based exposure limits (HBELs) are applied. In order to demonstrate its practical use, as well as any limitations and/or special considerations, this framework was applied to five dietary supplements (currently available to the public). We found that the detected levels of APIs in some dietary supplements were above the recommended dose of the drugs, and thus, pose a significant health risk to consumers and potentially workers involved in manufacturing of these supplements. The results support the value of increased product quality surveillance and perhaps regulatory activity.
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Carter JJ, Fretwell LV, Woolard J. Effects of 4 multitargeted receptor tyrosine kinase inhibitors on regional hemodynamics in conscious, freely moving rats. FASEB J 2016; 31:1193-1203. [PMID: 27986807 PMCID: PMC5295730 DOI: 10.1096/fj.201600749r] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/03/2016] [Indexed: 11/17/2022]
Abstract
VEGF inhibitors, including receptor tyrosine kinase inhibitors, are used as adjunct therapies in a number of cancer treatments. An emerging issue with these drugs is that most cause hypertension. To gain insight into the physiological mechanisms involved, we evaluated their regional hemodynamic effects in conscious rats. Male Sprague Dawley rats (350–450 g) were chronically implanted with pulsed Doppler flow probes (renal and mesenteric arteries, and the descending abdominal aorta) and catheters (jugular vein, peritoneal cavity, and distal abdominal aorta). Regional hemodynamics were measured over 4 d, before and after daily administration of cediranib (3 and 6 mg/kg, 3 and 6 mg/kg/h for 1 h, i.v.), sorafenib (10 and 20 mg/kg, 10 and 20 mg kg/h for 1 h, i.v.), pazopanib (30 and100 mg/kg, i.p.), or vandetanib (12.5 and 25 mg/kg, i.p.). All drugs evoked significant increases (P < 0.05; n = 7–8) in mean arterial pressure, which were generally accompanied by significant mesenteric and hindquarters, but not renal, vasoconstrictions. The hypertensive effects of cediranib were unaffected by losartan (10 mg/kg/h), bosentan (20 mg/kg/h), or a combination of phentolamine and propranolol (each 1 mg/kg/h), suggesting a need for new strategies to overcome them.—Carter, J. J., Fretwell, L. V., Woolard, J. Effects of 4 multitargeted receptor tyrosine kinase inhibitors on regional hemodynamics in conscious, freely moving rats.
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Affiliation(s)
- Joanne J Carter
- Cell Signalling Research Group, School of Life Sciences, Medical School, The University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom; and
| | - Laurice V Fretwell
- Faculty of Health and Life Sciences, De Montfort University, Leicester, United Kingdom
| | - Jeanette Woolard
- Cell Signalling Research Group, School of Life Sciences, Medical School, The University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom; and
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Bello NT, Walters AL, Verpeut JL, Cunha PP. High-fat diet-induced alterations in the feeding suppression of low-dose nisoxetine, a selective norepinephrine reuptake inhibitor. J Obes 2013; 2013:457047. [PMID: 23431425 PMCID: PMC3570928 DOI: 10.1155/2013/457047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 12/17/2012] [Indexed: 11/17/2022] Open
Abstract
Central noradrenergic pathways are involved in feeding and cardiovascular control, physiological processes altered by obesity. The present studies determined how high-fat feeding and body weight gain alter the sensitivity to the feeding suppression and neural activation to a selective norepinephrine reuptake inhibitor, nisoxetine. Acute administration of nisoxetine (saline: 0, 3, 10, and 30 mg/kg; i.p.) resulted in a dose-dependent reduction in the 24 h refeeding response in male Sprague Dawley rats maintained on standard chow. In a similar fashion, nisoxetine resulted in reductions in blood pressure and a compensatory increase in heart rate. From these studies, the 3 mg/kg dose was subthreshold. In a separate experiment, however, 10 wk exposure to a high-fat diet (60% fat) resulted in weight gain and significant feeding suppression following administration of nisoxetine (3 mg/kg) compared with animals fed a control diet (10% fat). Nisoxetine (3 mg/kg) also resulted in greater neural activation, as measured by c-Fos immunohistochemistry, in the arcuate nucleus of the hypothalamus in animals exposed to the high-fat diet. Such data indicate acute nisoxetine doses that suppress food intake can impact cardiovascular measures. It also suggests that the feeding suppression to a low-dose nisoxetine is enhanced as a result of high-fat diet and weight gain.
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Affiliation(s)
- Nicholas T Bello
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, 84 Lipman Drive, New Brunswick, NJ 08901, USA.
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6
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Gardiner SM, March JE, Kemp PA, Bennett T, Baker DJ. Possible involvement of GLP-1(9-36) in the regional haemodynamic effects of GLP-1(7-36) in conscious rats. Br J Pharmacol 2010; 161:92-102. [PMID: 20718742 DOI: 10.1111/j.1476-5381.2010.00867.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND AND PURPOSE The incretin hormone, glucagon-like peptide (GLP)-1(7-36), is rapidly cleaved by dipeptidyl peptidase 4 (DPP-4) into GLP-1(9-36), and although it is agreed that most, if not all, of the metabolic effects are attributable to the intact peptide, the degree to which the cardiovascular effects are due to the cleavage product is unclear. The purpose of this study was to measure the regional haemodynamic effects of GLP-1(7-36), and determine the extent to which the cardiovascular effects of GLP-1(7-36) were influenced by DPP-4 inhibition and reproduced by GLP-1(9-36). Additional experiments investigated the involvement of autonomic mechanisms in the cardiovascular effects of GLP-1(7-36). EXPERIMENTAL APPROACH Regional haemodynamic effects of bolus doses and 4 h infusions of GLP-1(7-36) amide and GLP-1(9-36) amide were measured in conscious, chronically instrumented rats; the influence of DPP-4 inhibition and autonomic blockade on responses to GLP-1(7-36) were also assessed. KEY RESULTS Glucagon-like peptide-1(7-36) had clear regional haemodynamic effects comprising tachycardia, a rise in blood pressure, renal and mesenteric vasoconstriction and hindquarters vasodilatation, whereas GLP-1(9-36) was devoid of any cardiovascular actions. The effects of GLP-1(7-36) were enhanced by DPP-4 inhibition, and the tachycardia and hindquarters vasodilatation were beta-adrenoceptor-mediated. CONCLUSIONS AND IMPLICATIONS In conscious rats, the cardiovascular effects of GLP-1(7-36) resemble those of the GLP analogue, exendin-4, and are attributable to the intact peptide rather than the cleavage product, GLP-1(9-36).
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Affiliation(s)
- S M Gardiner
- School of Biomedical Sciences, University of Nottingham, Nottingham, UK.
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7
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Kim SH, Lee J, Yoon T, Choi J, Choi D, Kim D, Kwon SW. Simultaneous determination of anti-diabetes/anti-obesity drugs by LC/PDA, and targeted analysis of sibutramine analog in dietary supplements by LC/MS/MS. Biomed Chromatogr 2009; 23:1259-65. [DOI: 10.1002/bmc.1248] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Thomas GH, Babbs AJ, Chatfield RE, Krülle TM, Widdowson PS, Provost D, McCormack JG. 5-HT(1A) activation counteracts cardiovascular but not hypophagic effects of sibutramine in rats. Obesity (Silver Spring) 2009; 17:467-73. [PMID: 19219064 DOI: 10.1038/oby.2008.550] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The noradrenaline (NA) and serotonin reuptake inhibitor, sibutramine, gives effective weight loss, but full efficacy cannot be attained at approved doses due to cardiovascular side effects. We assessed in rats the contributions of NA and serotonin transporters to sibutramine's hypophagic and cardiovascular effects, and whether selective 5-hydroxytryptamine (5-HT(1A)) receptor activation could counteract the latter without affecting the former. Food intake was assessed in freely feeding rats and cardiovascular parameters in conscious telemetered rats. Ex vivo radioligand binding was used to estimate brain monoamine transporter occupancy. Sibutramine (1-10 mg/kg p.o.) dose-dependently reduced food intake; however, 10 mg/kg p.o. markedly elevated blood pressure and heart rate. Sibutramine gave greater occupancy of NA than serotonin reuptake sites. Coadministration of the selective 5-HT(1A) agonist F-11440 (2.5 mg/kg p.o.) attenuated sibutramine-induced hypertension and tachycardia without altering its food intake effects. The selective NA reuptake inhibitors, nisoxetine or reboxetine, did not alter food intake alone, but each reduced food intake when combined with F-11440. These results suggest that sibutramine-induced hypophagic and cardiovascular effects are largely due to increased brain synaptic NA via NA reuptake inhibition, and that 5-HT(1A) activation can counter the undesirable cardiovascular effects resulting from increased sympathetic activity. Selective NA reuptake inhibitors did not reduce food intake alone but did when combined with 5-HT(1A) activation. Hence increased synaptic serotonin, via serotonin reuptake inhibition or 5-HT(1A) activation, together with increased NA, would appear to produce hypophagia. Thus weight loss with minimal cardiovascular risk could be achieved by 5-HT(1A) activation combined with NA transporter blockade.
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Gardiner SM, March JE, Kemp PA, Bennett T. Autonomic nervous system-dependent and -independent cardiovascular effects of exendin-4 infusion in conscious rats. Br J Pharmacol 2008; 154:60-71. [PMID: 18311183 DOI: 10.1038/bjp.2008.75] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Glucagon-like peptide-1 (GLP) receptor agonists are promising therapeutic agents for the treatment of type II diabetes, but effects other than those on glucoregulation need assessing. Cardiovascular actions of bolus doses of the GLP receptor agonist exendin-4 have been reported, but to date the effects of continuous infusions have not been described. EXPERIMENTAL APPROACH The regional haemodynamic effects and possible underlying mechanisms of 6 h infusions of exendin-4 were measured in conscious, chronically instrumented rats. KEY RESULTS A 6 h infusion of exendin-4 (up to 6 pmol kg(-1) min(-1)) only modestly influenced blood pressure, but caused substantial, opposing, regionally selective vascular effects and tachycardia. A major involvement of beta-adrenoceptors in the vasodilator and cardiac effects was identified, with little or no direct contribution from alpha-adrenoceptors to the vasoconstriction seen. Under conditions where alpha- and beta-adrenoceptors were antagonized, or when ganglionic transmission was blocked, a marked vasoconstrictor effect of exendin-4 was revealed in the mesenteric and hindquarters vascular beds (about 50% fall in vascular conductances). No role for endogenous angiotensin II, vasopressin, endothelin, neuropeptide Y or prostanoids could be shown in these vasoconstrictor actions of exendin-4. CONCLUSIONS AND IMPLICATIONS The results show not only an important involvement of the autonomic nervous system in the cardiovascular actions of exendin-4 infusion but also an underlying non-autonomically mediated vasoconstrictor action, the mechanism of which remains to be identified.
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Affiliation(s)
- S M Gardiner
- Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, University of Nottingham, Nottingham, Nottinghamshire, UK.
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Tizzano JP, Stribling DS, Perez-Tilve D, Strack A, Frassetto A, Chen RZ, Fong TM, Shearman L, Krieter PA, Tschöp MH, Skolnick P, Basile AS. The Triple Uptake Inhibitor (1R,5S)-(+)-1-(3,4-Dichlorophenyl)-3-azabicyclo[3.1.0] Hexane Hydrochloride (DOV 21947) Reduces Body Weight and Plasma Triglycerides in Rodent Models of Diet-Induced Obesity. J Pharmacol Exp Ther 2007; 324:1111-26. [DOI: 10.1124/jpet.107.133132] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Gardiner SM, March JE, Kemp PA, Maguire JJ, Kuc RE, Davenport AP, Bennett T. Regional heterogeneity in the haemodynamic responses to urotensin II infusion in relation to UT receptor localisation. Br J Pharmacol 2006; 147:612-21. [PMID: 16314853 PMCID: PMC1751348 DOI: 10.1038/sj.bjp.0706503] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The aim of the study was to measure regional haemodynamic responses to 6 h infusions of human urotensin II (hUII), to identify possible mediators of the effects observed, and to relate the findings to the distribution of urotensin II receptors (UT receptors). Male, Sprague-Dawley rats had pulsed Doppler flow probes and intravascular catheters implanted for measurement of regional haemodynamics in the conscious, freely moving state. Infusions of saline (0.4 ml h(-1)) or hUII (30, 300 and 3,000 pmol kg(-1) h(-1)) were given i.v. for 6 h, and the effects of pretreatment with indomethacin (5 mg kg(-1) h(-1)), N(G)-nitro-L-arginine methyl ester (L-NAME, 3 mg kg(-1) h(-1)) or propranolol (1 mg kg(-1); 0.5 mg kg(-1) h(-1)) on responses to hUII (300 pmol kg(-1) h(-1) for 6 h) were assessed. Cellular localisation of UT receptor-like immunoreactivity was determined in relevant tissues. hUII caused dose-dependent tachycardia and hindquarters vasodilatation, accompanied by a slowly developing rise in blood pressure. Haemodynamic effects of hUII were attenuated by propranolol or L-NAME and abolished by indomethacin. UT receptor-like immunoreactivity was detected in skeletal and vascular smooth muscle. The findings indicate that in conscious rats, infusions of hUII cause vasodilatation, which, of the vascular beds monitored, is selective for the hindquarters and dependent on cyclooxygenase products and nitric oxide. The pressor effect of hUII under these conditions is likely to be due to an increase in cardiac output, possibly due to a positive inotropic effect. UT receptor-like immunoreactivity present in skeletal muscle is consistent with the haemodynamic pattern.
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MESH Headings
- Adrenergic beta-Antagonists/pharmacology
- Animals
- Blood Pressure
- Cyclooxygenase Inhibitors/pharmacology
- Dose-Response Relationship, Drug
- Enzyme Inhibitors/pharmacology
- Heart Rate
- Hemodynamics/drug effects
- Hindlimb
- Indomethacin/pharmacology
- Infusions, Intravenous
- Male
- Muscle, Skeletal/blood supply
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- NG-Nitroarginine Methyl Ester/pharmacology
- Nitric Oxide Synthase/antagonists & inhibitors
- Nitric Oxide Synthase/metabolism
- Propranolol/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptors, G-Protein-Coupled/drug effects
- Receptors, G-Protein-Coupled/metabolism
- Regional Blood Flow
- Urotensins/administration & dosage
- Urotensins/pharmacology
- Vasodilation
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Affiliation(s)
- Sheila M Gardiner
- Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, University of Nottingham, Nottingham NG7 2UH.
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Gardiner SM, March JE, Kemp PA, Bennett T. Mesenteric Vasoconstriction and Hindquarters Vasodilatation Accompany the Pressor Actions of Exendin-4 in Conscious Rats. J Pharmacol Exp Ther 2005; 316:852-9. [PMID: 16221740 DOI: 10.1124/jpet.105.093104] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The hemodynamic effects of the glucagon-like peptide-1 (GLP-1) receptor agonist, exendin-4, and putative underlying mechanisms were assessed in conscious male Sprague-Dawley rats. At a dose of 25 ng kg(-1) i.v., exendin-4 had little effect, but doses of 250 and 2500 ng kg(-1) had significant tachycardic effects (+66 +/- 9 and +95 +/- 16 beats min(-1) at 5 min, respectively) and pressor actions (+10 +/- 2 and +12 +/- 1 mm Hg), accompanied by substantial falls in mesenteric vascular conductance (-38 +/- 3% and -47 +/- 3%) and increases in hindquarters vascular conductance (+82 +/- 14% and +126 +/- 15%). The latter were likely due to adrenaline-mediated activation of beta(2) adrenoceptors since they were abolished by the beta(2) adrenoceptor antagonist, ICI 118551 [(+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol) hydrochloride], or propranolol [(RS)-1-[(1-methylethyl)amino]-3-(1-naphthalenyloxy)-2-propanol], and absent in adrenal-demedullated rats. In the presence of beta-adrenoceptor antagonism, the tachycardic effects of exendin-4 were suppressed, but the pressor action was enhanced. Enhancement of the pressor action of exendin-4 was not seen in adrenal-demedullated rats or in animals given phentolamine in addition to propranolol, consistent with a component of the pressor action of exendin-4 being due to an adrenaline-mediated positive inotropic effect mediated by alpha-adrenoceptors. The mesenteric vasoconstrictor effect of exendin-4 was unaffected by antagonism of alpha-adrenoceptors, vasopressin receptors, angiotensin receptors, or GLP-1 receptors, although antagonism of the latter substantially inhibited the hindquarter vasodilator effects of exendin-4. These results are consistent with exendin-4 having cardiovascular effects through GLP-1 receptor-dependent and -independent mechanisms, some of which involve sympathoadrenal activation.
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Gardiner SM, March JE, Kemp PA, Bennett T. Involvement of CB1-receptors and beta-adrenoceptors in the regional hemodynamic responses to lipopolysaccharide infusion in conscious rats. Am J Physiol Heart Circ Physiol 2004; 288:H2280-8. [PMID: 15604130 DOI: 10.1152/ajpheart.00851.2004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A possible involvement of endocannabinoids in a chronic model of endotoxemia was assessed by measuring the regional (renal, mesenteric, hindquarters) hemodynamic responses to continuous 24-h LPS infusion (150 microg.kg(-1).h(-1)) in conscious, male Sprague-Dawley rats, in the absence or presence of the cannabinoid (CB1) receptor antagonist AM-251 (3 mg/kg). AM-251 inhibited the tachycardic and hindquarters vasodilator effects of LPS, but did not influence the other hemodynamic changes. In subsequent experiments, it was shown that the tachycardic and hindquarters vasodilator effects of LPS were also inhibited by the nonselective beta-adrenoceptor antagonist propranolol. In addition, the late (at 24 h) hindquarters vasodilator effects of LPS were inhibited by the beta2-adrenoceptor antagonist ICI-118551. Against the background of our previous work showing beta-adrenoceptor involvement in the cardiovascular effects of exogenous cannabinoids, we conclude that AM-251 may have been inhibiting endocannabinoid-modulated, sympathoadrenal-mediated activation of vasodilator beta-adrenoceptors in LPS-infused rats rather than suppressing a direct vasodilator action of endocannabinoids.
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Affiliation(s)
- S M Gardiner
- Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, United Kingdom.
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Gardiner SM, Nunez DJR, Baer PG, Brown KK, Bennett T. Regional hemodynamic effects of the N-(2-benzoylphenyl)-L-tyrosine peroxisome proliferator-activated receptor-gamma ligand, GI 262570 [(S)-2-(2-benzoylphenylamino)-3-[4-[2-(5-methyl-2-phenyl-2-oxazol-4-yl)ethoxy]phenyl]propionic acid], in conscious rats. J Pharmacol Exp Ther 2004; 310:1226-33. [PMID: 15126643 DOI: 10.1124/jpet.104.068817] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
This study provides novel data on the regional hemodynamic effects of the peroxisome proliferator-activated receptor-gamma activator, GI 262570 [(S)-2-(2-benzoylphenylamino)-3-[4-[2-(5-methyl-2-phenyl-2-oxazol-4-yl)ethoxy]phenyl]propionic acid], in conscious, male Sprague-Dawley rats. Administration of GI 262570 twice daily for 4 days caused a slowly developing, modest fall in mean arterial blood pressure, associated with a progressive, hyperemic hindquarters vasodilatation, but with no consistent changes in renal or mesenteric hemodynamics. The hindquarters vasodilator effect of GI 262570 was not inhibited by the beta2-adrenoceptor antagonist, ICI 118551 ((+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl) amino]-2-butanol hydrochloride), and was still apparent in the presence of the alpha-adrenoceptor antagonist, phentolamine. Neither the latter, nor antagonism of angiotensin (AT1) and endothelin (ETA and ETB) receptors unmasked vasodilator responses to GI 262570 in the renal or mesenteric vascular beds. In the presence of GI 262570, vasodilator responses to acetylcholine and vasoconstrictor responses to methoxamine were normal. Furthermore, the cardiovascular responses to nonselective nitric-oxide synthase inhibition were not influenced by GI 262570. Collectively, these results indicate that the vasodilator action of GI 262570 is specific to the hindquarters vascular bed (of those studied), does not involve alpha- or beta2-adrenoceptors, and is not associated with a change in basal or stimulated nitric oxide release.
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Affiliation(s)
- Sheila M Gardiner
- Centre for Integrated Systems Biology, School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK.
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