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Author Martel, E.; Ponchon, P.; Champeroux, P.; Elghozi, J.L.; Renaud De La Faverie, J.F.; Dabire, H.; Pannier, B.; Richard, S.; Safar, M.; Cuche, J.L. isbn  openurl
  Title Mechanisms of the cardiovascular deconditioning induced by tail suspension in the rat Type Miscellaneous
  Year 1998 Publication Abbreviated Journal  
  Volume Issue Pages H1667-H1673  
  Keywords Mechanisms, cardiovascular, cardiovascular deconditioning, tail suspension, rat, Animal, Blood Pressure/physiology, Cardiovascular Deconditioning/physiology, Catecholamines/blood, Heart Rate/physiology, Hindlimb Suspension, Male, Rats, Rats, Wistar, Rec  
  Abstract The aim of the present work was to obtain insights into the pathophysiology of cardiovascular deconditioning (CVD) induced by tail suspension (TS) in the rat: during TS, when central venous pressure (CVP) has been normalized (E. Martel, P. Champeroux, P. Lacolley, S. Richard, M. Safar, and J. L. Cuche. J. Appl. Physiol. 80: 1390-1396, 1996), and during simulated orthostatism (SO), when transient episodes of hypotension and bradycardia are disclosed, bradycardia with SO represents a response that seems peculiar to the rat compared with humans. According to basic physiology, a reduced activity of the sympathetic system induced by increased CVP was suspected but was not supported by data obtained through spectral analysis of blood pressure (BP) and heart rate (HR) variability or measurements of plasma catecholamine concentration during TS. Nonetheless, indirect evidence was obtained. During SO, plasma catecholamine concentration was lower in TS rats than in controls, suggesting a reduced synthesis of catecholamines, itself secondary to reduced activity of the sympathetic system. Furthermore, after 48 h of TS, the number of binding sites and affinity of alpha-receptors in rat aorta were increased, compatible with a reduced level of neurotransmitter in the synaptic cleft. A second series of experiments was carried out to study hypotension and bradycardia in TS rats during SO. Hypersensitivity of serotonergic mechanisms was suspected. Two 5-HT3 receptor antagonists (ondansetron and MDL-72222) blocked hypotension and restored tachycardia, basic features of orthostatic adaptation of the circulatory system. Response to the 5-HT3 receptor agonist was measured through dose-response curves of BP and HR after injection of 2-methylserotonin. After low doses, hypotension (10 micrograms/kg) and bradycardia (3 and 10 micrograms/kg) were significantly greater in 48-h TS rats than in controls. Thus CVD in the rat induced by TS appears to implicate at least two mechanisms: reduced activity of the sympathetic system and hypersensitivity of serotonergic mechanisms.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title Journal Article  
  Series Volume (down) 274 Series Issue 5 Pt 2 Edition  
  ISSN ISBN 0363-6135 Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Martel1998 Serial 9404  
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Author Leppäranta, M.; Palosuo, E.; Grönvall, H.; Kalliosaari, S.; Seinä, A.; Peltola, J. (eds) openurl 
  Title Phases of the ice season in the Baltic Sea (North of 57°N) Type Book Whole
  Year 1988 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Ice; Ice Extent / Cover; Baltic Sea  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Finnish Institute of Marine Research Place of Publication Helsinki Editor Leppäranta, M.; Palosuo, E.; Grönvall, H.; Kalliosaari, S.; Seinä, A.; Peltola, J.  
  Language Summary Language Original Title  
  Series Editor Series Title Finnish Marine Research Abbreviated Series Title Finnish Mar Res  
  Series Volume (down) 254 Series Issue Edition  
  ISSN 0357-1076 ISBN Medium  
  Area Baltic Sea Expedition Conference  
  Notes Approved no  
  Call Number refbase @ admin @ Leppaeranta++1988BalticIcePhases Serial 2155  
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Author Mälkki, P.; Tamsalu, R. isbn  openurl
  Title Physical features of the Baltic Sea Type Book Whole
  Year 1985 Publication Abbreviated Journal  
  Volume Issue Pages 110 pp  
  Keywords Baltic Sea; Bottom Topography; Climate; Salinity; Temperature; Ice; Ice Extent / Cover  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Finnish Institute of Marine Research Place of Publication Helsinki Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Finnish Marine Research Abbreviated Series Title Finnish Mar Res  
  Series Volume (down) 252 Series Issue Edition  
  ISSN 0357-1076 ISBN 951-46-8594-6 Medium  
  Area Expedition Conference  
  Notes authors report that ice coverage lasts for 2 to 6 months (mean: 3 months) on the SW coast of Finland Approved no  
  Call Number refbase @ admin @ Maelkki+Tamsalu1985BalticPhysicalFeatures Serial 2156  
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Author Chaouche-teyara, K.; Fournier, B.; Safar, M.; Dabire, H. isbn  openurl
  Title Vascular and cardiac effects of alpha-methyl-5-HT and DOI are mediated by different 5-HT receptors in the pithed rat Type Miscellaneous
  Year 1993 Publication Abbreviated Journal  
  Volume Issue Pages 67-75  
  Keywords alpha-methyl-5-HT, DOI, 5-HT, 5-HT Receptors, Receptors, Pithed Rat, Rat, Alpha-methyl-5-hydroxytryptamine  
  Abstract In pithed rats, alpha-methyl-5-hydroxytryptamine (alpha-methyl-5-HT) increased blood pressure and heart rate, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) almost exclusively increased blood pressure and 1-(3-chlorophenyl)piperazine (mCPP), heart rate. The maximal responses relative to 5-HT indicate that alpha-methyl-5-HT may be a full agonist at vascular and cardiac 5-HT receptors, DOI a partial agonist at both receptors and mCPP a full agonist at cardiac 5-HT receptors but a partial agonist at vascular 5-HT receptors. The alpha 1-adrenoceptor antagonist, 2-[2-[4(o-methoxyphenyl)-piperazine-1-yl]-ethyl]4,4-dimethyl -1,3(2H-4H) isoquinolinedione (AR-C 239), did not change the pressor and tachycardiac effects of alpha-methyl-5-HT and DOI, excluding the participation of alpha 1-adrenoceptors. 4-Isopropyl-7-methyl-9-(2-hydroxy-1-methylpropoxycarbonyl) 4,6,6a,7,8,9,10,10a-octahydroindolo[4,3-fg]quinoline (LY 53857), spiperone and ketanserin but not propranolol antagonised the pressor effect of alpha-methyl-5-HT, indicating a preferential participation of 5-HT2 receptors although an implication of 5-HT1C receptors could not be ruled out. Spiperone, spiperone plus propranolol, LY 53857, ketanserin and propranolol antagonised the pressor effects of DOI suggesting the stimulation of both 5-HT2 and 5-HT1C receptors. Propranolol and spiperone plus propranolol suppressed the weak increase in heart rate induced by DOI, indicating the stimulation of 5-HT1C receptors. However, propranolol and LY 53857 only antagonised the tachycardiac effects of a high dose of alpha-methyl-5-HT. We hypothesised that the pressor and tachycardiac effects of these agonists may be mediated by 5-HT2 and 5-HT1C receptors, respectively. However, the availability of specific 5-HT1C and/or 5-HT2 receptor antagonists is necessary to verify our hypothesis and before a clear-cut conclusion can be drawn.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title Genuine article  
  Series Volume (down) 250 Series Issue 1 Edition  
  ISSN ISBN 0014-2999 Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Chaouche-teyara1993b Serial 8894  
Permanent link to this record
 

 
Author Chaouche-teyara, K.; Fournier, B.; Safar, M.; Dabire, H. isbn  openurl
  Title Vascular and cardiac effects of alpha-methyl-5-HT and DOI are mediated by different 5-HT receptors in the pithed rat Type Miscellaneous
  Year 1993 Publication Abbreviated Journal  
  Volume Issue Pages 67-75  
  Keywords alpha-methyl-5-HT, DOI, 5-HT, 5-HT Receptors, Receptors, Pithed Rat, Rat, Alpha-methyl-5-hydroxytryptamine  
  Abstract In pithed rats, alpha-methyl-5-hydroxytryptamine (alpha-methyl-5-HT) increased blood pressure and heart rate, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) almost exclusively increased blood pressure and 1-(3-chlorophenyl)piperazine (mCPP), heart rate. The maximal responses relative to 5-HT indicate that alpha-methyl-5-HT may be a full agonist at vascular and cardiac 5-HT receptors, DOI a partial agonist at both receptors and mCPP a full agonist at cardiac 5-HT receptors but a partial agonist at vascular 5-HT receptors. The alpha 1-adrenoceptor antagonist, 2-[2-[4(o-methoxyphenyl)-piperazine-1-yl]-ethyl]4,4-dimethyl -1,3(2H-4H) isoquinolinedione (AR-C 239), did not change the pressor and tachycardiac effects of alpha-methyl-5-HT and DOI, excluding the participation of alpha 1-adrenoceptors. 4-Isopropyl-7-methyl-9-(2-hydroxy-1-methylpropoxycarbonyl) 4,6,6a,7,8,9,10,10a-octahydroindolo[4,3-fg]quinoline (LY 53857), spiperone and ketanserin but not propranolol antagonised the pressor effect of alpha-methyl-5-HT, indicating a preferential participation of 5-HT2 receptors although an implication of 5-HT1C receptors could not be ruled out. Spiperone, spiperone plus propranolol, LY 53857, ketanserin and propranolol antagonised the pressor effects of DOI suggesting the stimulation of both 5-HT2 and 5-HT1C receptors. Propranolol and spiperone plus propranolol suppressed the weak increase in heart rate induced by DOI, indicating the stimulation of 5-HT1C receptors. However, propranolol and LY 53857 only antagonised the tachycardiac effects of a high dose of alpha-methyl-5-HT. We hypothesised that the pressor and tachycardiac effects of these agonists may be mediated by 5-HT2 and 5-HT1C receptors, respectively. However, the availability of specific 5-HT1C and/or 5-HT2 receptor antagonists is necessary to verify our hypothesis and before a clear-cut conclusion can be drawn.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title Genuine article  
  Series Volume (down) 250 Series Issue 1 Edition  
  ISSN ISBN 0014-2999 Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Chaouche-teyara1993b Serial 9086  
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