1
|
Rabelo ER, Ruschel K, Moreno H, Rubira M, Consolim-Colombo FM, Irigoyen MC, Rohde LE. Venous endothelial function in heart failure: Comparison with healthy controls and effect of clinical compensation. Eur J Heart Fail 2014; 10:758-64. [DOI: 10.1016/j.ejheart.2008.06.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 05/02/2008] [Accepted: 06/09/2008] [Indexed: 11/28/2022] Open
Affiliation(s)
- Eneida R. Rabelo
- Cardiovascular Division of Hospital de Clínicas de Porto Alegre, The Post-Graduation Programs in Biology?Physiology and Cardiology?Cardiovascular Sciences; Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil, The Heart Institute (InCor); São Paulo SP Brazil
| | - Karen Ruschel
- Cardiovascular Division of Hospital de Clínicas de Porto Alegre, The Post-Graduation Programs in Biology?Physiology and Cardiology?Cardiovascular Sciences; Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil, The Heart Institute (InCor); São Paulo SP Brazil
| | - Heitor Moreno
- Cardiovascular Division of Hospital de Clínicas de Porto Alegre, The Post-Graduation Programs in Biology?Physiology and Cardiology?Cardiovascular Sciences; Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil, The Heart Institute (InCor); São Paulo SP Brazil
| | - Marcelo Rubira
- Cardiovascular Division of Hospital de Clínicas de Porto Alegre, The Post-Graduation Programs in Biology?Physiology and Cardiology?Cardiovascular Sciences; Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil, The Heart Institute (InCor); São Paulo SP Brazil
| | - Fernanda M. Consolim-Colombo
- Cardiovascular Division of Hospital de Clínicas de Porto Alegre, The Post-Graduation Programs in Biology?Physiology and Cardiology?Cardiovascular Sciences; Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil, The Heart Institute (InCor); São Paulo SP Brazil
| | - Maria Cláudia Irigoyen
- Cardiovascular Division of Hospital de Clínicas de Porto Alegre, The Post-Graduation Programs in Biology?Physiology and Cardiology?Cardiovascular Sciences; Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil, The Heart Institute (InCor); São Paulo SP Brazil
| | - Luis E. Rohde
- Cardiovascular Division of Hospital de Clínicas de Porto Alegre, The Post-Graduation Programs in Biology?Physiology and Cardiology?Cardiovascular Sciences; Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil, The Heart Institute (InCor); São Paulo SP Brazil
| |
Collapse
|
2
|
Blood pressure regulation VIII: resistance vessel tone and implications for a pro-atherogenic conduit artery endothelial cell phenotype. Eur J Appl Physiol 2013; 114:531-44. [PMID: 23860841 DOI: 10.1007/s00421-013-2684-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 06/15/2013] [Indexed: 10/26/2022]
Abstract
Dysfunction of the endothelium is proposed as the primary initiator of atherosclerotic peripheral artery disease, which occurs mainly in medium- to large-sized conduit arteries of the lower extremities (e.g., iliac, femoral, popliteal arteries). In this review article, we propose the novel concept that conduit artery endothelial cell phenotype is determined, in part, by microvascular tone in skeletal muscle resistance arteries through both changes in arterial blood pressure as well as upstream conduit artery shear stress patterns. First, we summarize the literature supporting the involvement of sympathetic nerve activity (SNA) and nitric oxide (NO) in the modulation of microvascular tone and arterial blood pressure. We then focus on the role of elevated blood pressure and shear stress profiles in modulating conduit artery endothelial cell phenotype. Last, we discuss findings from classic and emerging studies indicating that increased vascular resistance, as it occurs in the context of increased SNA and/or reduced NO bioavailability, is associated with greater oscillatory shear stress (e.g., increased retrograde shear) in upstream conduit arteries. The ideas put forth in this review set the stage for a new paradigm concerning the mechanistic link between increased microvascular tone and development of conduit artery endothelial dysfunction and thus increased risk for peripheral artery disease. Indeed, a vast amount of evidence supports the notion that excessive blood pressure and oscillatory shear stress are potent pro-atherogenic signals to the endothelium.
Collapse
|
3
|
Rabelo ER, Rohde LE, Schaan BD, Rubira MC, Ruschel KB, Plentz RDM, Consolim-Colombo FM, Irigoyen MC, Moreno Junior H. Bradykinin or acetylcholine as vasodilators to test endothelial venous function in healthy subjects. Clinics (Sao Paulo) 2008; 63:677-82. [PMID: 18925329 PMCID: PMC2664727 DOI: 10.1590/s1807-59322008000500017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Accepted: 07/29/2008] [Indexed: 01/22/2023] Open
Abstract
INTRODUCTION The evaluation of endothelial function has been performed in the arterial bed, but recently evaluation within the venous system has also been explored. Endothelial function studies employ different drugs that act as endothelium-dependent vasodilatory response inductors. OBJECTIVES The aim of this study is to compare the endothelium-dependent venous vasodilator response mediated by either acetylcholine or bradykinin in healthy volunteers. METHODS AND RESULTS Changes in vein diameter after phenylephrine-induced venoconstriction were measured to compare venodilation induced by acetylcholine or bradykinin (linear variable differential transformer dorsal hand vein technique). We studied 23 healthy volunteers; 31% were male, and the subject had a mean age of 33 +/- 8 years and a mean body mass index of 23 +/- 2 kg/m(2). The maximum endothelium-dependent venodilation was similar for both drugs (p = 0.13), as well as the mean responses for each dose of both drugs (r = 0.96). The maximum responses to acetylcholine and bradykinin also had good agreement. CONCLUSION There were no differences between acetylcholine and bradykinin as venodilators in this endothelial venous function investigation.
Collapse
Affiliation(s)
- Eneida R Rabelo
- Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Giribela CRG, Rubira MC, Melo NRD, Plentz RDM, Angelis KD, Moreno H, Consolim-Colombo FM. Effect of a low-dose oral contraceptive on venous endothelial function in healthy young women: preliminary results. Clinics (Sao Paulo) 2007; 62:151-8. [PMID: 17505700 DOI: 10.1590/s1807-59322007000200010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Accepted: 10/24/2006] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND A possible increase in the incidence of venous thromboembolic events has been reported among users of third generation oral contraceptives. The objective of this study was to evaluate the effect of a low dose oral contraceptive (15 microg ethinyl estradiol/60 microg gestodene) on the venous endothelial function of healthy young women. METHODS Prospective case control study using the dorsal hand vein technique. Venous endothelial function was evaluated at baseline and after 4 months in the oral contraceptive users group (11 women) and in a control group (9 women). After preconstriction of the vein with phenylephrine, dose-response curves for acetylcholine and sodium nitroprusside were constructed. RESULTS In the contraceptive users group, a reduction occurred in the maximum venodilation response to acetylcholine and sodium nitroprusside after 4 months of oral contraceptive use, but this difference was not statistically significant (P > 0.05). No significant changes were detected in maximum venodilation responses to acetylcholine and sodium nitroprusside at the 4-month time point in the control group. CONCLUSION This study found no significant impairment of endothelium-dependent or independent venodilation in healthy young women following oral contraceptive use. Further studies are necessary using the same methodology in a larger sample over a longer follow-up period.
Collapse
|
5
|
Fricker R, Hesse C, Weiss J, Tayrouz Y, Hoffmann MM, Unnebrink K, Mansmann U, Haefeli WE. Endothelial venodilator response in carriers of genetic polymorphisms involved in NO synthesis and degradation. Br J Clin Pharmacol 2004; 58:169-77. [PMID: 15255799 PMCID: PMC1884579 DOI: 10.1111/j.1365-2125.2004.02130.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AIMS Polymorphisms of the NOSIII gene and of the CYBA gene have been associated with a number of pathological conditions such as arterial hypertension, coronary artery disease, and myocardial infarction. Because endothelium-dependent vasodilation is impaired in these disorders, we hypothesized that polymorphisms of NOSIII or CYBA might modulate endothelial function of venous capacitance vessels already before cardiovascular disease becomes overt. METHODS Endothelium-dependent and -independent venodilation was assessed by measuring local vascular responses to bradykinin and sodium nitroprusside in the dorsal hand vein after preconstriction with phenylephrine in 72 healthy male Caucasians after careful exclusion of cardiovascular risk factors. Genotyping was performed for polymorphisms of the NOSIII gene (T-786C, G894T, (CA)(n)) and the CYBA gene (C242T). RESULTS Genotype distribution for each polymorphism followed the Hardy-Weinberg equilibrium. In all studied single nucleotide polymorphisms no significant difference between the respective genotypes and the venodilator response to either sodium nitroprusside or bradykinin was observed, and the number of CA repeat copies was not related to the venodilator response to bradykinin. Mean venodilation induced by bradykinin 50 ng min(-1) (+/-SEM) for homozygote carriers of the single nucleotide polymorphisms was 48.9 +/- 8.5% venodilation (G894T; wild type: 49.8 +/- 6.9), 50.3 +/- 11.0% venodilation (T-786C; wild type: 42.6 +/- 5.2), and 30.4 +/- 9.1% venodilation (C242T; wild type: 49.2 +/- 6.0), respectively. CONCLUSIONS This study suggests that the studied polymorphisms of NOSIII and CYBA do not significantly modulate endothelium-dependent venodilation in individuals without vascular risk factors.
Collapse
Affiliation(s)
- Ruth Fricker
- Department of Internal Medicine VI, Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Lewis TV, Dart AM, Chin-Dusting JP. Endothelium-dependent relaxation by acetylcholine is impaired in hypertriglyceridemic humans with normal levels of plasma LDL cholesterol. J Am Coll Cardiol 1999; 33:805-12. [PMID: 10080485 DOI: 10.1016/s0735-1097(98)00667-6] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Patients with high triglyceride (of which very low density lipoproteins [VLDL] are the main carriers), but with normal low density lipoprotein (LDL) cholesterol levels, were examined for in vivo endothelium function status. BACKGROUND Very low density lipoproteins inhibit endothelium-dependent, but not -independent, vasorelaxation in vitro. METHODS Three groups were studied: 1) healthy volunteers (n = 10; triglyceride 1.24+/-0.14 mmol/liter, LDL cholesterol 2.99+/-0.24 mmol/liter); 2) hypertriglyceridemic (n = 11; triglyceride 6.97+/-1.19 mmol/liter, LDL cholesterol 2.17+/-0.2 mmol/liter, p < 0.05); and 3) hypercholesterolemic (n = 10; triglyceride 2.25+/-0.29 mmol/liter, LDL cholesterol 5.61+/-0.54 mmol/liter; p < 0.05) patients. Vasoactive responses to acetylcholine, sodium nitroprusside, noradrenaline, N(G)-monomethyl-L-arginine and postischemic hyperemia were determined using forearm venous occlusion plethysmography. RESULTS Responses to acetylcholine (37 microg/min) were significantly dampened both in hypercholesterolemic (% increase in forearm blood flow: 268.2+/-62) and hypertriglyceridemic patients (232.6+/-45.2) when compared with controls (547.8+/-108.9; ANOVA p < 0.05). Responses to sodium nitroprusside (at 1.6 microg/min: controls vs. hypercholesterolemics vs. hypertriglyceridemic: 168.7+/- 25.1 vs. 140.6+/-38.9 vs. 178.5+/-54.5% increase), noradrenaline, N(G)-monomethyl-L-arginine and postischemic hyperemic responses were not different among the groups examined. CONCLUSIONS Acetylcholine responses are impaired in patients with pathophysiologic levels of plasma triglycerides but normal plasma levels of LDL cholesterol. The impairment observed was comparable to that obtained in hypercholesterolemic patients. We conclude that impaired responses to acetylcholine normally associated with hypercholesterolemia also occur in hypertriglyceridemia. These findings identify a potential mechanism by which high plasma triglyceride levels may be atherogenic independent of LDL cholesterol levels.
Collapse
Affiliation(s)
- T V Lewis
- Alfred and Baker Medical Unit, Baker Medical Research Institute and The Alfred Hospital, Prahran, Victoria, Australia
| | | | | |
Collapse
|
7
|
Chin-Dusting JP, Kaye DM. Restoration of nitric oxide function in human hyperlipidaemia, congestive heart failure and liver cirrhosis. Clin Exp Pharmacol Physiol 1998; 25:645-52. [PMID: 9750951 DOI: 10.1111/j.1440-1681.1998.tb02271.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. There is accumulating evidence for a range of abnormalities in the nitric oxide (NO) signalling cascade in human cardiovascular disorders. 2. In the present review we assess the literature detailing such evidence in early (hyperlipidaemia) and end-stage (heart failure) disease, with emphasis on the mechanisms by which the disturbances are thought to occur. 3. Strategies for the correction of disturbed NO signalling in these states are reviewed and include both prescribed pharmacological interventions, such as lipid-lowering therapy and novel uses of angiotensin-converting enzyme inhibitors, as well as non-pharmacological interventions, such as exercise and dietary supplementation with L-arginine and n-3 polyunsaturated fatty acids. 4. In addition to a decreased production/function of NO, the possible detrimental effects of a chronic elevation in NO production in patients with liver cirrhosis, together with a novel use of antibiotics to correct this perturbation, is outlined.
Collapse
Affiliation(s)
- J P Chin-Dusting
- Alfred and Baker Medical Unit, Baker Medical Research Institute, Victoria, Australia.
| | | |
Collapse
|
8
|
Moreno H, Chalon S, Urae A, Tangphao O, Abiose AK, Hoffman BB, Blaschke TF. Endothelial dysfunction in human hand veins is rapidly reversible after smoking cessation. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:H1040-5. [PMID: 9724311 DOI: 10.1152/ajpheart.1998.275.3.h1040] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cigarette smoking has been shown to impair endothelium-dependent dilation in arteries. We tested the hypothesis that cigarette smoking also impairs endothelium-dependent venodilation and evaluated changes in this response after smoking cessation in a time-course study using the dorsal hand vein technique. Dose-response curves were constructed in smokers and nonsmokers by infusing bradykinin (1-278 ng/min), an endothelium-dependent vasodilator, and nitroglycerin (0.006-1,583 ng/min), an endothelium-independent vasodilator, into hand veins preconstricted with the selective alpha1-adrenergic agonist phenylephrine. The maximal venodilation induced by bradykinin was 89 +/- 5% in controls (n = 16) and 61 +/- 7% in smokers (n = 18; P = 0.02). No difference in nitroglycerin-induced venodilation was observed between the two groups. Coinfusion of L-arginine (0.33 mg/min) markedly improved the bradykinin-induced venodilation in smokers (52 +/- 7 to 90 +/- 9%; P < 0.01). After acute smoking cessation (n = 7), restoration to normal bradykinin-induced venodilation was observed within 24 h, whereas no change in the response to a maximally effective dose of nitroglycerin (1,583 ng/min) was detected. In a human vein model appropriate for testing vascular functional alterations, this study demonstrates that smoking impairs endothelium-dependent venodilation in heavy smokers. Moreover, this endothelial dysfunction appears to be rapidly reversible after smoking cessation. This model may be useful in studies evaluating mechanisms of endothelial dysfunction and interventions to modify it.
Collapse
Affiliation(s)
- H Moreno
- Division of Clinical Pharmacology, Department of Medicine, Stanford University School of Medicine, Stanford 94305-5130, USA
| | | | | | | | | | | | | |
Collapse
|
9
|
Hand MF, Haynes WG, Webb DJ. Hemodialysis and L-arginine, but not D-arginine, correct renal failure-associated endothelial dysfunction. Kidney Int 1998; 53:1068-77. [PMID: 9551419 DOI: 10.1111/j.1523-1755.1998.00851.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In end-stage renal failure (ESRF) symptomatic hemodialysis-related hypotension may prevent effective provision of renal replacement therapy. Endogenous inhibitors of nitric oxide synthase accumulate in ESRF and are cleared by dialysis. We, therefore, hypothesised that removal of these inhibitors by hemodialysis would increase endothelial nitric oxide generation and promote venodilation. In vivo responses of norepinephrine preconstricted dorsal hand veins to locally active doses of acetylcholine (an activator of nitric oxide synthase) and glyceryl trinitrate (GTN; a nitric oxide donor) were examined in patients undergoing maintenance hemodialysis for ESRF and in healthy age- and sex-matched controls. Patient studies were undertaken before and after dialysis. Studies before dialysis were repeated with co-infusion of either L-arginine or its inactive enantiomer D-arginine. Venodilation in response to acetylcholine was impaired before, and corrected by, dialysis whereas venodilation to GTN was similar before and after dialysis. Venodilation in response to acetylcholine before dialysis was restored by co-infusion of L- but not D-arginine. Therefore, patients with ESRF undergoing hemodialysis have impaired acetylcholine-mediated venodilation consistent with the accumulation in ESRF of functionally important inhibitors of nitric oxide synthase that are cleared by dialysis.
Collapse
Affiliation(s)
- M F Hand
- Clinical Pharmacology Unit & Research Centre, University of Edinburgh, Western General Hospital, Scotland, United Kingdom
| | | | | |
Collapse
|
10
|
Deng X, Wang X, Andersson R. Influence of anti-inflammatory and antioxidant agents on endothelial permeability alterations induced by bradykinin. J INVEST SURG 1996; 9:337-49. [PMID: 8951657 DOI: 10.3109/08941939609021275] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Increased vascular permeability to plasma proteins and altered hemodynamics at the site of inflammation are characteristics of inflammation. In the present study, alterations in endothelial barrier permeability were evaluated in different organs/tissues 6 h after a systemic inflammatory response induced by intravenous injection of bradykinin (BK; 1.7 mg/kg). The effect of intravenous pretreatment with indomethacin or ibuprofen (cyclooxygenase inhibitors), N-acetyl-L-cysteine (NAC, an oxygen free radical scavenger), and allopurinol (a xanthine oxidase inhibitor) was determined. Endothelial permeability was evaluated by determining tissue water content (TWC), 125I-labeled human serum albumin (HSA) flux, and albumin leakage index (ALI) in various organs/tissues. The vasodilation in the local tissues was reflected by tissue blood content (TBC), measured by 51Cr-labeled red blood cells. The results indicate that albumin flux significantly increased in the peritoneum, pancreas, stomach, PSI, DSI, colon, kidneys, liver, lungs, and brain, TBC significantly increased in the kidneys, liver, lungs, and heart, as well as in the intestine, and an increased ALI, assaying endothelial permeability considering local hemodynamic alterations was noted in the pancreas, kidneys, liver, lungs, PSI, and DSI in the group with BK alone. These changes were to varying degrees reversed by pretreatment with indomethacin, ibuprofen, N-acetyl-L-cysteine, or allopurinol, where the protective effect tended to be organ-dependent.
Collapse
Affiliation(s)
- X Deng
- Department of Surgery, Lund University Hospital, Sweden
| | | | | |
Collapse
|
11
|
Peduzzi P, Simper D, Linder L, Strobel WM, Haefeli WE. Neuropeptide Y in human hand veins: pharmacologic characterization and interaction with cyclic guanosine monophosphate-dependent venodilators in vivo. Clin Pharmacol Ther 1995; 58:675-83. [PMID: 8529333 DOI: 10.1016/0009-9236(95)90024-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The dorsal hand vein compliance technique was used to study direct vascular effects of human neuropeptide Y in vivo. Human neuropeptide Y is an endogenous vasoconstrictor peptide that is costored with norepinephrine in sympathetic nerve endings and coreleased with the catecholamine under various physiologic and pathologic conditions. Compared with the alpha 1-adrenergic agonist phenylephrine (geometric mean dose-rate that produces the half-maximal response [ED50]: 1.05 nmol/min; maximum venoconstriction [Emax] +/- SEM, expressed as a percentage of baseline compliance: 91% +/- 3%), human neuropeptide Y was nine times more potent (geometric mean ED50: 0.122 nmol/min; p < 0.001) but markedly less efficacious (Emax: 58% +/- 4%; n = 12; p < 0.001). Venoconstrictor effects of human neuropeptide Y lasted several hours and were unchanged by simultaneous administration of alpha-adrenergic antagonists but were readily reversed by nitroglycerin or bradykinin. The high responsiveness of subcutaneous veins to human neuropeptide Y indicates that human neuropeptide Y may regulate venous compliance and filling of the venous subcutaneous capacitance bed in vivo.
Collapse
Affiliation(s)
- P Peduzzi
- Department of Internal Medicine, University Hospital, Basel, Switzerland
| | | | | | | | | |
Collapse
|
12
|
Roullet JB, Xue H, Roullet CM, Fletcher WS, Cipolla MJ, Harker CT, McCarron DA. Mevalonate availability affects human and rat resistance vessel function. J Clin Invest 1995; 96:239-44. [PMID: 7615793 PMCID: PMC185194 DOI: 10.1172/jci118027] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Previous data in rat conductance vessels indicated that cellular mevalonate contributes to vascular tone and systemic blood pressure control. Using exogenous mevalonate (M) or lovastatin, a 3-hydroxy-3-methyl-glutaryl CoA (HMG-CoA) reductase inhibitor (L), we characterized the role of mevalonate availability in resistance artery function, both in experimental animals and humans. Rat mesenteric artery resistance vessels (MARV, n = 9) were incubated for 48 h with either L, M, L + M, or vehicle (V) and tested for reactivity to NE, serotonin, acetylcholine, atrial natriuretic peptide, and sodium nitroprusside (SNP). Lovastatin increased sensitivity to NE (P < 0.03) and serotonin (P < 0.003), and significantly impaired the response to all three vasodilators. These effects were reversed by co-incubation with mevalonate. Mevalonate alone had no effect. In separate experiments, intravascular free Ca2+ concentration (ivfCa2+) was determined in fura-2AM loaded MARV. Basal ivfCa2+ was increased after a 48-h exposure to L (52.7 +/- 4.6 nM, L, vs. 29.7 +/- 2.4 nM, V, n = 12, P < 0.003), as were ivfCa2+ levels following stimulation with low (100 nM) NE concentrations. Similar ivfCa2+ concentrations were achieved during maximum contraction with NE (10 mM) in both groups. Human resistance arteries of human adipose tissue were also studied. Lovastatin increased the sensitivity to NE (ED50 = 372 +/- 56 nM, V, and 99 +/- 33 nM, L, P < 0.001) and significantly decreased the relaxation to acetylcholine and SNP of human vessels. We conclude that mevalonate availability directly contribute to resistance vessel function and vascular signal transduction systems in both experimental animals and humans. The study calls for the identification of non-sterol, mevalonate-derived vasoactive metabolites, and suggests that disorders of the mevalonate pathway can alter vascular tone and cause hypertension.
Collapse
Affiliation(s)
- J B Roullet
- Department of Nephrology, Hypertension and Clinical Pharmacology, Oregon Health Sciences University, Portland 97201, USA
| | | | | | | | | | | | | |
Collapse
|
13
|
|