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Stearns SA, Xun H, Haddad A, Rinkinen J, Bustos VP, Lee BT. Therapeutic Options for Migraines in the Microsurgical Patient: A Scoping Review. Plast Reconstr Surg 2024; 153:988e-1001e. [PMID: 37337332 DOI: 10.1097/prs.0000000000010861] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
BACKGROUND There exists an increasing array of treatments proposed to prevent, alleviate, and abort symptoms of a migraine; however, for patients who undergo reconstructive microsurgery, caution must be taken to preserve vascular integrity. This study is the first-to-date scoping review of vascular and bleeding risk of current migraine therapies, with the purpose of identifying potential therapeutic agents for postoperative migraine management appropriate for microsurgical patients. METHODS Currently available migraine therapeutics were compiled from the UpToDate software system and the American Academy of Family Physicians. A PubMed literature review was performed for each therapeutic's effect on bleeding or vascular involvement. Data were compiled into tables of abortive, symptom-controlling and prophylactic, and nonpharmacologic treatments. Expert microsurgeons reviewed the data to provide recommendations for optimized patient care. RESULTS Triptans and other ergot derivatives demonstrated strong evidence of vasoconstriction and were greatly advised against for immediate postmicrosurgical use. Novel pharmaceutical therapies such as lasmiditan and calcitonin gene-related peptide antagonists have no literature indicating potential for vasoconstriction or hematoma and remain an investigational option for abortive medical treatment. For symptom control, acetaminophen appears the safest option, with clinical judgment and further research needed for use of nonsteroidal antiinflammatory drugs. Alternative treatment techniques may include migraine prophylaxis with botulinum toxin injection or nutraceutical treatment by means of magnesium supplementation or coenzyme Q10 administration, minimizing the need for additional medication in the postoperative setting. CONCLUSIONS Patients undergoing reconstructive microsurgery have a unique medical profile limiting the therapeutic options available to treat migraines. This review provides preliminary evidence to be considered as a guide for prescribing therapeutics for migraine in the postoperative setting.
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Affiliation(s)
| | - Helen Xun
- the Division of Plastic and Reconstructive Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School
| | - Anthony Haddad
- the Division of Plastic and Reconstructive Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School
| | - Jacob Rinkinen
- the Division of Plastic and Reconstructive Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School
| | - Valeria P Bustos
- the Division of Plastic and Reconstructive Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School
| | - Bernard T Lee
- the Division of Plastic and Reconstructive Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School
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2
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Limberg JK, Johansson RE, Carter KJ, Peltonen GL, Harrell JW, Kellawan JM, Eldridge MW, Sebranek JJ, Walker BJ, Schrage WG. Preserved β-adrenergic-mediated vasodilation in skeletal muscle of young adults with obesity despite shifts in cyclooxygenase and nitric oxide synthase. Am J Physiol Heart Circ Physiol 2022; 322:H25-H35. [PMID: 34738833 PMCID: PMC8698505 DOI: 10.1152/ajpheart.00449.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Central adiposity is associated with greater sympathetic support of blood pressure. β-adrenergic receptors (β-AR) buffer sympathetically mediated vasoconstriction and β-AR-mediated vasodilation is attenuated in preclinical models of obesity. With this information, we hypothesized β-AR vasodilation would be lower in obese compared with normal weight adults. Because β-AR vasodilation in normal weight adults is limited by cyclooxygenase (COX) restraint of nitric oxide synthase (NOS), we further explored the contributions of COX and NOS to β-AR vasodilation in this cohort. Forearm blood flow (FBF, Doppler ultrasound) and mean arterial blood pressure (MAP, brachial arterial catheter) were measured and forearm vascular conductance (FVC) was calculated (FVC = FBF/MAP). The rise in FVC from baseline (ΔFVC) was quantified during graded brachial artery infusion of isoproterenol (Iso, 1-12 ng/100 g/min) in normal weight (n = 36) and adults with obesity (n = 22) (18-40 yr old). In a subset of participants, Iso-mediated vasodilation was examined before and during inhibition of NOS [NG-monomethyl-l-arginine (l-NMMA)], COX (ketorolac), and NOS + COX (l-NMMA + ketorolac). Iso-mediated increases in FVC did not differ between groups (P = 0.57). l-NMMA attenuated Iso-mediated ΔFVC in normal weight (P = 0.03) but not adults with obesity (P = 0.27). In normal weight adults, ketorolac increased Iso-mediated ΔFVC (P < 0.01) and this response was lost with concurrent l-NMMA (P = 0.67). In contrast, neither ketorolac (P = 0.81) nor ketorolac + l-NMMA (P = 0.40) altered Iso-mediated ΔFVC in adults with obesity. Despite shifts in COX and NOS, β-AR vasodilation is preserved in young adults with obesity. These data highlight the presence of a compensatory shift in microvascular control mechanisms in younger humans with obesity.NEW & NOTEWORTHY We examined β-adrenergic receptor-mediated vasodilation in skeletal muscle of humans with obesity and normal weight. Results show that despite shifts in the contribution of cyclooxygenase and nitric oxide synthase, β-adrenergic-mediated vasodilation is relatively preserved in young, otherwise healthy adults with obesity. These data highlight the presence of subclinical changes in microvascular control mechanisms early in the obesity process and suggest duration of obesity and/or the addition of primary aging may be necessary for overt dysfunction.
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Affiliation(s)
- Jacqueline K. Limberg
- 1Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri,2Department of Kinesiology, University of Wisconsin, Madison, Wisconsin
| | | | - Katrina J. Carter
- 2Department of Kinesiology, University of Wisconsin, Madison, Wisconsin
| | - Garrett L. Peltonen
- 2Department of Kinesiology, University of Wisconsin, Madison, Wisconsin,3School of Nursing and Kinesiology, Western New Mexico University, Silver City, New Mexico
| | - John W. Harrell
- 2Department of Kinesiology, University of Wisconsin, Madison, Wisconsin,4711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio
| | - J. Mikhail Kellawan
- 2Department of Kinesiology, University of Wisconsin, Madison, Wisconsin,5Department of Health and Exercise Science, University of Oklahoma, Norman, Oklahoma
| | - Marlowe W. Eldridge
- 2Department of Kinesiology, University of Wisconsin, Madison, Wisconsin,6Department of Pediatrics, University of Wisconsin, Madison, Wisconsin
| | - Joshua J. Sebranek
- 7Department of Anesthesiology, University of Wisconsin, Madison, Wisconsin
| | - Benjamin J. Walker
- 7Department of Anesthesiology, University of Wisconsin, Madison, Wisconsin
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3
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Bock JM, Hughes WE, Ueda K, Feider AJ, Hanada S, Casey DP. Glycemic management is inversely related to skeletal muscle microvascular endothelial function in patients with type 2 diabetes. Physiol Rep 2021; 9:e14764. [PMID: 33660935 PMCID: PMC7931618 DOI: 10.14814/phy2.14764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 11/24/2022] Open
Abstract
Microvascular endothelial dysfunction precipitates cardiovascular disease mortality in patients with type 2 diabetes mellitus (T2DM). However, the relationship between glycemic management and microvascular endothelial function of these patients remains ill defined. We investigated the association between skeletal muscle microvascular endothelial function with glycemic management (HbA1c) and responses to an oral glucose challenge (OGTT) in 30 patients with T2DM (59 ± 9 years, 31.2 ± 5.1 kg/m2 , HbA1c = 7.3 ± 1.3%). On study day 1, microvascular endothelial function was quantified as the increase (Δ from rest) in forearm vascular conductance (FVC, ml/min/100 mmHg) during intra-arterial acetylcholine infusion at 4.0 and 8.0 μg/dl forearm volume/min (ACh4 and ACh8, respectively). [Glucose] and [insulin] were measured in a fasted state as well as following a 75 g OGTT on a second day with an additional fasting blood sample collected to measure HbA1c. FVC increased (Δ) 221 ± 118 and 251 ± 144 ml/min/100 mm Hg during ACh4 and ACh8 trials, respectively (p < 0.05 between doses). [Glucose] and [insulin] increased at the 1-h time point, relative to fasting levels, and remained elevated 2 h post-consumption (p < 0.05 for both variables and time points). [Glucose] nor [insulin], fasting or during the OGTT, were associated with ΔFVC during ACh4 or ACh8, respectively (p = 0.11-0.86), although HbA1c was inversely related (r = -0.47 and -0.46, respectively, p < 0.01 for both). Patients whose HbA1c met the ADA's therapeutic target of ≤7.0% had greater ΔFVC to ACh4 (272 ± 147 vs. 182 ± 74 ml/100 mm Hg/min) and ACh8 (324 ± 171 vs. 196 ± 90 ml/100 mm Hg/min, p < 0.05 for both trials) compared to those with >7.0%, respectively. Our data show glycemic management is related to acetylcholine-mediated vasodilation (e.g., microvascular endothelial function) in skeletal muscle of patients with T2DM.
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Affiliation(s)
- Joshua M Bock
- Department of Physical Therapy & Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - William E Hughes
- Department of Physical Therapy & Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Kenichi Ueda
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Andrew J Feider
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Satoshi Hanada
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Darren P Casey
- Department of Physical Therapy & Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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4
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Trinity JD, Kwon OS, Broxterman RM, Gifford JR, Kithas AC, Hydren JR, Jarrett CL, Shields KL, Bisconti AV, Park SH, Craig JC, Nelson AD, Morgan DE, Jessop JE, Bledsoe AD, Richardson RS. The role of the endothelium in the hyperemic response to passive leg movement: looking beyond nitric oxide. Am J Physiol Heart Circ Physiol 2020; 320:H668-H678. [PMID: 33306447 DOI: 10.1152/ajpheart.00784.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Passive leg movement (PLM) evokes a robust and predominantly nitric oxide (NO)-mediated increase in blood flow that declines with age and disease. Consequently, PLM is becoming increasingly accepted as a sensitive assessment of endothelium-mediated vascular function. However, a substantial PLM-induced hyperemic response is still evoked despite nitric oxide synthase (NOS) inhibition. Therefore, in nine young healthy men (25 ± 4 yr), this investigation aimed to determine whether the combination of two potent endothelium-dependent vasodilators, specifically prostaglandin (PG) and endothelium-derived hyperpolarizing factor (EDHF), account for the remaining hyperemic response to the two variants of PLM, PLM (60 movements) and single PLM (sPLM, 1 movement), when NOS is inhibited. The leg blood flow (LBF, Doppler ultrasound) response to PLM and sPLM following the intra-arterial infusion of NG-monomethyl-l-arginine (l-NMMA), to inhibit NOS, was compared to the combined inhibition of NOS, cyclooxygenase (COX), and cytochrome P-450 (CYP450) by l-NMMA, ketorolac tromethamine (KET), and fluconazole (FLUC), respectively. NOS inhibition attenuated the overall LBF [area under the curve (LBFAUC)] response to both PLM (control: 456 ± 194, l-NMMA: 168 ± 127 mL, P < 0.01) and sPLM (control: 185 ± 171, l-NMMA: 62 ± 31 mL, P = 0.03). The combined inhibition of NOS, COX, and CYP450 (i.e., l-NMMA+KET+FLUC) did not further attenuate the hyperemic responses to PLM (LBFAUC: 271 ± 97 mL, P > 0.05) or sPLM (LBFAUC: 72 ± 45 mL, P > 0.05). Therefore, PG and EDHF do not collectively contribute to the non-NOS-derived NO-mediated, endothelium-dependent hyperemic response to either PLM or sPLM in healthy young men. These findings add to the mounting evidence and understanding of the vasodilatory pathways assessed by the PLM and sPLM vascular function tests.NEW & NOTEWORTHY Passive leg movement (PLM) evokes a highly nitric oxide (NO)-mediated hyperemic response and may provide a novel evaluation of vascular function. The contributions of endothelium-dependent vasodilatory pathways, beyond NO and including prostaglandins and endothelium-derived hyperpolarizing factor, to the PLM-induced hyperemic response to PLM have not been evaluated. With intra-arterial drug infusion, the combined inhibition of nitric oxide synthase (NOS), cyclooxygenase, and cytochrome P-450 (CYP450) pathways did not further diminish the hyperemic response to PLM compared with NOS inhibition alone.
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Affiliation(s)
- Joel D Trinity
- Geriatric Research, Education, and Clinical Center, Department of Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Oh Sung Kwon
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Kinesiology, University of Connecticut, Storrs, Connecticut
| | - Ryan M Broxterman
- Geriatric Research, Education, and Clinical Center, Department of Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Jayson R Gifford
- Geriatric Research, Education, and Clinical Center, Department of Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Exercise Science, Brigham Young University, Provo, Utah
| | - Andrew C Kithas
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Jay R Hydren
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Catherine L Jarrett
- Geriatric Research, Education, and Clinical Center, Department of Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Katherine L Shields
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Angela V Bisconti
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Soung Hun Park
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Jesse C Craig
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Ashley D Nelson
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - David E Morgan
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Jacob E Jessop
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Amber D Bledsoe
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Russell S Richardson
- Geriatric Research, Education, and Clinical Center, Department of Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
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5
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Trinity JD, Broxterman RM, Richardson RS. Regulation of exercise blood flow: Role of free radicals. Free Radic Biol Med 2016; 98:90-102. [PMID: 26876648 PMCID: PMC4975999 DOI: 10.1016/j.freeradbiomed.2016.01.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 01/07/2016] [Accepted: 01/21/2016] [Indexed: 02/07/2023]
Abstract
During exercise, oxygen and nutrient rich blood must be delivered to the active skeletal muscle, heart, skin, and brain through the complex and highly regulated integration of central and peripheral hemodynamic factors. Indeed, even minor alterations in blood flow to these organs have profound consequences on exercise capacity by modifying the development of fatigue. Therefore, the fine-tuning of blood flow is critical for optimal physical performance. At the level of the peripheral circulation, blood flow is regulated by a balance between the mechanisms responsible for vasodilation and vasoconstriction. Once thought of as toxic by-products of in vivo chemistry, free radicals are now recognized as important signaling molecules that exert potent vasoactive responses that are dependent upon the underlying balance between oxidation-reduction reactions or redox balance. Under normal healthy conditions with low levels of oxidative stress, free radicals promote vasodilation, which is attenuated with exogenous antioxidant administration. Conversely, with advancing age and disease where background oxidative stress is elevated, an exercise-induced increase in free radicals can further shift the redox balance to a pro-oxidant state, impairing vasodilation and attenuating blood flow. Under these conditions, exogenous antioxidants improve vasodilatory capacity and augment blood flow by restoring an "optimal" redox balance. Interestingly, while the active skeletal muscle, heart, skin, and brain all have unique functions during exercise, the mechanisms by which free radicals contribute to the regulation of blood flow is remarkably preserved across each of these varied target organs.
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Affiliation(s)
- Joel D Trinity
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA; Department of Internal Medicine, Division of Geriatric, University of Utah, Salt Lake City, UT, USA.
| | - Ryan M Broxterman
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA; Department of Internal Medicine, Division of Geriatric, University of Utah, Salt Lake City, UT, USA
| | - Russell S Richardson
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA; Department of Internal Medicine, Division of Geriatric, University of Utah, Salt Lake City, UT, USA; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
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6
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Limberg JK, Johansson RE, Peltonen GL, Harrell JW, Kellawan JM, Eldridge MW, Sebranek JJ, Schrage WG. β-Adrenergic-mediated vasodilation in young men and women: cyclooxygenase restrains nitric oxide synthase. Am J Physiol Heart Circ Physiol 2016; 310:H756-64. [PMID: 26747505 DOI: 10.1152/ajpheart.00886.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/06/2016] [Indexed: 01/22/2023]
Abstract
We tested the hypothesis that women exhibit greater vasodilator responses to β-adrenoceptor stimulation compared with men. We further hypothesized women exhibit a greater contribution of nitric oxide synthase and cyclooxygenase to β-adrenergic-mediated vasodilation compared with men. Forearm blood flow (Doppler ultrasound) was measured in young men (n = 29, 26 ± 1 yr) and women (n = 33, 25 ± 1 yr) during intra-arterial infusion of isoproterenol (β-adrenergic agonist). In subset of subjects, isoproterenol responses were examined before and after local inhibition of nitric oxide synthase [N(G)-monomethyl-l-arginine (l-NMMA); 6 male/10 female] and/or cyclooxygenase (ketorolac; 5 male/5 female). Vascular conductance (blood flow ÷ mean arterial pressure) was calculated to assess vasodilation. Vascular conductance increased with isoproterenol infusion (P < 0.01), and this effect was not different between men and women (P = 0.41). l-NMMA infusion had no effect on isoproterenol-mediated dilation in men (P > 0.99) or women (P = 0.21). In contrast, ketorolac infusion markedly increased isoproterenol-mediated responses in both men (P < 0.01) and women (P = 0.04) and this rise was lost with subsequent l-NMMA infusion (men, P < 0.01; women, P < 0.05). β-Adrenergic vasodilation is not different between men and women and sex differences in the independent contribution of nitric oxide synthase and cyclooxygenase to β-mediated vasodilation are not present. However, these data are the first to demonstrate β-adrenoceptor activation of cyclooxygenase suppresses nitric oxide synthase signaling in human forearm microcirculation and may have important implications for neurovascular control in both health and disease.
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Affiliation(s)
| | | | | | - John W Harrell
- Department of Kinesiology, University of Wisconsin, Madison, Wisconsin
| | | | - Marlowe W Eldridge
- Department of Kinesiology, University of Wisconsin, Madison, Wisconsin; Department of Pediatrics, University of Wisconsin, Madison, Wisconsin; and
| | - Joshua J Sebranek
- Department of Anesthesiology, University of Wisconsin, Madison, Wisconsin
| | - William G Schrage
- Department of Kinesiology, University of Wisconsin, Madison, Wisconsin;
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7
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Harrell JW, Johansson RE, Evans TD, Sebranek JJ, Walker BJ, Eldridge MW, Serlin RC, Schrage WG. Preserved Microvascular Endothelial Function in Young, Obese Adults with Functional Loss of Nitric Oxide Signaling. Front Physiol 2015; 6:387. [PMID: 26733880 PMCID: PMC4686588 DOI: 10.3389/fphys.2015.00387] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 11/30/2015] [Indexed: 01/04/2023] Open
Abstract
Data indicate endothelium-dependent dilation (EDD) may be preserved in the skeletal muscle microcirculation of young, obese adults. Preserved EDD might be mediated by compensatory mechanisms, impeding insight into preclinical vascular dysfunction. We aimed to determine the functional roles of nitric oxide synthase (NOS) and cyclooxygenase (COX) toward EDD in younger obese adults. We first hypothesized EDD would be preserved in young, obese adults. Further, we hypothesized a reduced contribution of NOS in young, obese adults would be replaced by increased COX signaling. Microvascular EDD was assessed with Doppler ultrasound and brachial artery infusion of acetylcholine (ACh) in younger (27 ± 1 year) obese (n = 29) and lean (n = 46) humans. Individual and combined contributions of NOS and COX were examined with intra-arterial infusions of l-NMMA and ketorolac, respectively. Vasodilation was quantified as an increase in forearm vascular conductance (ΔFVC). Arterial endothelial cell biopsies were analyzed for protein expression of endothelial nitric oxide synthase (eNOS). ΔFVC to ACh was similar between groups. After l-NMMA, ΔFVC to ACh was greater in obese adults (p < 0.05). There were no group differences in ΔFVC to ACh with ketorolac. With combined NOS-COX inhibition, ΔFVC was greater in obese adults at the intermediate dose of ACh. Surprisingly, arterial endothelial cell eNOS and phosphorylated eNOS were similar between groups. Younger obese adults exhibit preserved EDD and eNOS expression despite functional dissociation of NOS-mediated vasodilation and similar COX signaling. Compensatory NOS- and COX-independent vasodilatory mechanisms conceal reduced NOS contributions in otherwise healthy obese adults early in life, which may contribute to vascular dysfunction.
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Affiliation(s)
- John W Harrell
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison Madison, WI, USA
| | - Rebecca E Johansson
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison Madison, WI, USA
| | - Trent D Evans
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison Madison, WI, USA
| | - Joshua J Sebranek
- Department of Anesthesiology, University of Wisconsin Hospital and Clinics, University of Wisconsin-Madison Madison, WI, USA
| | - Benjamin J Walker
- Department of Anesthesiology, University of Wisconsin Hospital and Clinics, University of Wisconsin-Madison Madison, WI, USA
| | - Marlowe W Eldridge
- The John Rankin Laboratory of Pulmonary Medicine, Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-MadisonMadison, WI, USA; Department of Pediatrics, University of Wisconsin Hospital and Clinics, University of Wisconsin-MadisonMadison, WI, USA
| | - Ronald C Serlin
- Department of Educational Psychology, University of Wisconsin-Madison Madison, WI, USA
| | - William G Schrage
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison Madison, WI, USA
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8
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Eisenach JH, Gullixson LR, Allen AR, Kost SL, Nicholson WT. Cyclo-oxygenase-2 inhibition and endothelium-dependent vasodilation in younger vs. older healthy adults. Br J Clin Pharmacol 2015; 78:815-23. [PMID: 24698105 DOI: 10.1111/bcp.12397] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 03/29/2014] [Indexed: 12/01/2022] Open
Abstract
AIM A major feature of endothelial dysfunction is reduced endothelium-dependent vasodilation, which in ageing may be due to decreased production of endothelial prostacyclin, or nitric oxide (NO), or both. METHOD We tested this hypothesis in 12 younger (age 18-38 years, six women) and 12 older healthy adults (age 55-73 years, six post-menopausal women). Endothelium-dependent vasodilation was assessed by the forearm vascular conductance (FVC) response to intra-arterial acetylcholine (ACh) (0.5, 1.0, 2.0, 4.0 μg dl(-1) forearm tissue min(-1) ) before and 90 min after inhibition of the enzyme cyclo-oxygenase-2 (COX-2) with oral celecoxib (400 mg), followed by the addition of endothelial NO synthase inhibition with intra-arterial N(G) -monomethyl-l arginine acetate (L-NMMA). RESULTS Ageing was associated with a significantly reduced FVC response to ACh (P = 0.009, age-by-dose interaction; highest dose FVC ± SEM in ageing: 11.2 ± 1.4 vs. younger: 17.7 ± 2.4 units, P = 0.02). Celecoxib did not reduce resting FVC or the responses to ACh in any group. L-NMMA significantly reduced resting FVC and the responses to ACh in all groups, and absolute FVC values following L-NMMA were similar between groups. CONCLUSION In healthy normotensive younger and older adults, there is minimal contribution of prostacyclin to ACh-mediated vasodilation, yet the NO component of vasodilation is reduced with ageing. In the clinical context, these findings suggest that acute administration of medications that inhibit prostacyclin (i.e. COX-2 inhibitors) evoke modest vascular consequences in healthy persons. Additional studies are necessary to test whether chronic use of COX-2 medications reduces endothelium dependent vasodilation in older persons with or without cardiovascular risk factors.
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Affiliation(s)
- John H Eisenach
- Departments of Anesthesiology, Physiology and Biomedical Engineering, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905
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9
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Arce-Esquivel AA, Bunker AK, Simmons GH, Yang HT, Laughlin MH, Terjung RL. Impaired Coronary Endothelial Vasorelaxation in a Preclinical Model of Peripheral Arterial Insufficiency. ACTA ACUST UNITED AC 2015; 1. [PMID: 26726316 PMCID: PMC4696773 DOI: 10.15436/2378-6914/15/010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The present study was designed to determine whether adult swine with peripheral artery insufficiency (PAI) would exhibit vascular dysfunction in vessels distinct from the affected distal limbs, the coronary conduit arteries. Moreover, we sought to evaluate the effect of exercise training on coronary vasomotor function in PAI. Eighteen female healthy young Yucatan miniature swine were randomly assigned to either occluded exercise trained (Occl-Ex, n=7), or occluded-sedentary (Occl-Sed, n=5), or non-occluded, non-exercised control (Non-Occl-Con, n=6) groups. Occl-Ex pigs were progressively trained by running on a treadmill (5days/week, 12 weeks). The left descending artery (LAD) and left circumflex (LCX) coronary arteries were harvested. Vasorelaxation to adenosine diphosphate (ADP), bradykinin (BK), and sodium nitro-prusside (SNP) were assessed in LAD’s; while constrictor responses to phenylephrine (PE), angiotensin II (Ang II), and endothelin-1 (ET-1) were assessed in LCX’s. Vasorelaxation to ADP was reduced in LADs from Occl-Sed and Occl-Ex pigs (P<0.001) as compared to Non-Occl-Con pigs; however, Occl-Ex pigs exhibited partial recovery (P<0.001) intermediate to the other two groups. BK induced relaxation was reduced in LADs from Occl-Ex and Occl-Sed pigs (P<0.001), compared to Non-Occl-Con, and exercise modestly increased responses to BK (P<0.05). In addition, SNP, PE, Ang II, and ET-1 responses were not significantly different among the groups. Our results indicate that ‘simple’ occlusion of the femoral arteries induces vascular dysfunction in conduit vessels distinct from the affected hindlimbs, as evident in blunted coronary vasorelaxation responses to ADP and BK. These findings imply that PAI, even in the absence of frank atherogenic vascular disease, contributes to vascular dysfunction in the coronary arteries that could exacerbate disease outcome in patients with peripheral artery disease. Further, regular daily physical activity partially recovered the deficit observed in the coronary arteries.
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Affiliation(s)
- A A Arce-Esquivel
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri ; Department of Health and Kinesiology, The University of Texas at Tyler, Tyler, Texas
| | | | - G H Simmons
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
| | - H T Yang
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
| | - M H Laughlin
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri ; Department of Medical Pharmacology and Physiology, College of Medicine, University of Missouri, Columbia, Missouri ; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - R L Terjung
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri ; Department of Medical Pharmacology and Physiology, College of Medicine, University of Missouri, Columbia, Missouri ; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
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10
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Dautzenberg M, Just A. Temporal characteristics of nitric oxide-, prostaglandin-, and EDHF-mediated components of endothelium-dependent vasodilation in the kidney. Am J Physiol Regul Integr Comp Physiol 2013; 305:R987-98. [DOI: 10.1152/ajpregu.00526.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endothelium-dependent vasodilation is mediated by nitric oxide (NO), prostaglandins (PG), and endothelium-derived hyperpolarizing factor (EDHF). We studied the contributions and temporal characteristics of these components in the renal vasodilator responses to acetylcholine (ACh) and bradykinin (BK) and in the buffering of vasoconstrictor responses to norepinephrine (NE) and angiotensin II (ANG II). Renal blood flow (RBF) and vascular conductance (RVC) were studied in anesthetized rats in response to renal arterial bolus injections before and after inhibition of NO-synthase ( NG-nitro-l-arginine methyl ester, l-NAME), cyclooxygenase (indomethacin, INDO), or both. ACh increased RVC peaking at maximal time ( tmax) = 29 s. l-NAME ( n = 8) diminished the integrated response and made it substantially faster ( tmax = 18 s). The point-by-point difference caused by l-NAME (= NO component) integrated to 74% of control and was much slower ( tmax = 38 s). INDO ( n = 9) reduced the response without affecting tmax (36 vs. 30 s). The difference (= PG) reached 21% of the control with tmax = 25 s. l-NAME+INDO ( n = 17) reduced the response to 18% and markedly accelerated tmax to 16s (= EDHF). Results were similar for BK with slightly more PG and less NO contribution than for ACh. Constrictor responses to NE and ANG II were augmented and decelerated by l-NAME and l-NAME+INDO. The calculated difference (= buffering by NO or NO+PG) was slower than the constriction. It is concluded that NO, PG, and EDHF contribute >50%, 20–40%, and <20% to the renal vasodilator effect of ACh and BK, respectively. EDHF acts substantially faster and less sustained ( tmax = 16 s) than NO and PG ( tmax = 30 s). Constrictor buffering by NO and PG is not constant over time, but renders the constriction less sustained.
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Affiliation(s)
- Marcel Dautzenberg
- Physiologisches Institut der Universität Freiburg, Germany; and
- Freiburg Institute for Advanced Studies (FRIAS), Universität Freiburg, Germany
| | - Armin Just
- Physiologisches Institut der Universität Freiburg, Germany; and
- Freiburg Institute for Advanced Studies (FRIAS), Universität Freiburg, Germany
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11
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Trinity JD, Wray DW, Witman MAH, Layec G, Barrett-O'Keefe Z, Ives SJ, Conklin JD, Reese V, Richardson RS. Contribution of nitric oxide to brachial artery vasodilation during progressive handgrip exercise in the elderly. Am J Physiol Regul Integr Comp Physiol 2013; 305:R893-9. [PMID: 23948773 DOI: 10.1152/ajpregu.00311.2013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
UNLABELLED The reduction in nitric oxide (NO)-mediated vascular function with age has largely been determined by flow-mediated dilation (FMD). However, in light of recent uncertainty surrounding the NO dependency of FMD and the recognition that brachial artery (BA) vasodilation during handgrip exercise is predominantly NO-mediated in the young, we sought to determine the contribution of NO to BA vasodilation in the elderly using the handgrip paradigm. BA vasodilation during progressive dynamic (1 Hz) handgrip exercise performed at 3, 6, 9, and 12 kg was assessed with and without NO synthase (NOS) inhibition [intra-arterial N(G)-monomethyl-l-arginine (l-NMMA)] in seven healthy older subjects (69 ± 2 yr). Handgrip exercise in the control condition evoked significant BA vasodilation at 6 (4.7 ± 1.4%), 9 (6.5 ± 2.2%), and 12 kg (9.5 ± 2.7%). NOS inhibition attenuated BA vasodilation, as the first measurable increase in BA diameter did not occur until 9 kg (4.0 ± 1.8%), and the change in BA diameter at 12 kg was reduced by ∼30% (5.1 ± 2.2%), with unaltered shear rate ( CONTROL 407 ± 57, l-NMMA: 427 ± 67 s(-1)). Although shifted downward, the slope of the relationship between BA diameter and shear rate during handgrip exercise was unchanged ( CONTROL 0.0013 ± 0.0004, l-NMMA: 0.0011 ± 0.007, P = 0.6) as a consequence of NOS inhibition. Thus, progressive handgrip exercise in the elderly evokes a robust BA vasodilation, the magnitude of which was only minimally attenuated following NOS inhibition. This modest contribution of NO to BA vasodilation in the elderly supports the use of the handgrip exercise paradigm to assess NO-dependent vasodilation across the life span.
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Affiliation(s)
- Joel D Trinity
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, Utah
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12
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Limberg JK, Harrell JW, Johansson RE, Eldridge MW, Proctor LT, Sebranek JJ, Schrage WG. Microvascular function in younger adults with obesity and metabolic syndrome: role of oxidative stress. Am J Physiol Heart Circ Physiol 2013; 305:H1230-7. [PMID: 23934859 DOI: 10.1152/ajpheart.00291.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Older adults with cardiovascular disease exhibit microvascular dysfunction and increased levels of reactive oxygen species (ROS). We hypothesized that microvascular impairments begin early in the disease process and can be improved by scavenging ROS. Forearm blood flow (Doppler ultrasound) was measured in 45 young (32 ± 2 yr old) adults (n = 15/group) classified as lean, obese, and metabolic syndrome (MetSyn). Vasodilation in response to endothelial (ACh) and vascular smooth muscle [nitroprusside (NTP) and epoprostenol (Epo)] agonists was tested before and after intra-arterial infusion of ascorbic acid to scavenge ROS. Vasodilation was assessed as a rise in relative vascular conductance (ml·min(-1)·dl(-1)·100 mmHg(-1)). ACh and NTP responses were preserved (P = 0.825 and P = 0.924, respectively), whereas Epo responses were lower in obese and MetSyn adults (P < 0.05) than in lean controls. Scavenging of ROS via infusion of ascorbic acid resulted in an increase in ACh-mediated (P < 0.001) and NTP-mediated (P < 0.001) relative vascular conductance across all groups, suggesting that oxidative stress influences vascular responsiveness in adults with and without overt cardiovascular disease risk. Ascorbic acid had no effect on Epo-mediated vasodilation (P = 0.267). These results suggest that obese and MetSyn adults exhibit preserved endothelium-dependent vasodilation with reduced dependence on prostacyclin and are consistent with an upregulation of compensatory vascular control mechanisms.
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Affiliation(s)
- Jacqueline K Limberg
- Department of Kinesiology, School of Education, University of Wisconsin, Madison, Wisconsin
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13
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Zhou Z, Hemradj V, de Beer VJ, Gao F, Hoekstra M, Merkus D, Duncker DJ. Cytochrome P-450 2C9 exerts a vasoconstrictor influence on coronary resistance vessels in swine at rest and during exercise. Am J Physiol Heart Circ Physiol 2012; 302:H1747-55. [PMID: 22307673 DOI: 10.1152/ajpheart.00648.2011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A significant endothelium-dependent vasodilation persists after inhibition of nitric oxide synthase (NOS) and cyclooxygenase (COX) in the coronary vasculature, which has been linked to the activation of cytochrome P-450 (CYP) epoxygenases expressed in endothelial cells and subsequent generation of vasodilator epoxyeicosatrienoic acids. Here, we investigated the contribution of CYP 2C9 metabolites to regulation of porcine coronary vasomotor tone in vivo and in vitro. Twenty-six swine were chronically instrumented. Inhibition of CYP 2C9 with sulfaphenazole (5 mg/kg iv) alone had no effect on bradykinin-induced endothelium-dependent coronary vasodilation in vivo but slightly attenuated bradykinin-induced vasodilation in the presence of combined NOS/COX blockade with N(ω)-nitro-L-arginine (20 mg/kg iv) and indomethacin (10 mg/kg iv). Sulfaphenazole had minimal effects on coronary resistance vessel tone at rest or during exercise. Surprisingly, in the presence of combined NOS/COX blockade, a significant coronary vasodilator response to sulfaphenzole became apparent, both at rest and during exercise. Subsequently, we investigated in isolated porcine coronary small arteries (∼250 μm) the possible involvement of reactive oxygen species (ROS) in the paradoxical vasoconstrictor influence of CYP 2C9 activity. The vasodilation by bradykinin in vitro in the presence of NOS/COX blockade was markedly potentiated by sulfaphenazole under control conditions but not in the presence of the ROS scavenger N-(2-mercaptoproprionyl)-glycine. In conclusion, CYP 2C9 can produce both vasoconstrictor and vasodilator metabolites. Production of these metabolites is enhanced by combined NOS/COX blockade and is critically dependent on the experimental conditions. Thus production of vasoconstrictors slightly outweighed the production of vasodilators at rest and during exercise. Pharmacological stimulation with bradykinin resulted in vasodilator CYP 2C9 metabolite production when administered in vivo, whereas vasoconstrictor CYP 2C9 metabolites, most likely ROS, were dominant when administered in vitro.
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Affiliation(s)
- Zhichao Zhou
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School Erasmus University Rotterdam, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
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14
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Eisenach JH, Gullixson LR, Kost SL, Joyner MJ, Turner ST, Nicholson WT. Sex differences in salt sensitivity to nitric oxide dependent vasodilation in healthy young adults. J Appl Physiol (1985) 2011; 112:1049-53. [PMID: 22194324 DOI: 10.1152/japplphysiol.01197.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Dietary sodium and blood pressure regulation differs between normotensive men and women, an effect which may involve endothelial production of nitric oxide (NO). Therefore, we tested the hypothesis that differences in the NO component of endothelium-dependent vasodilation between low and high dietary sodium intake depend on sex. For 5 days prior to study, healthy adults consumed a controlled low-sodium diet (10 mmol/day, n = 30, mean age ± SE: 30 ± 1 yr, 16 men) or high-sodium diet (400 mmol/day, n = 36, age 23 ± 1 yr, 13 men). Forearm blood flow (FBF, plethysmography) responses to brachial artery administration of acetylcholine (ACh, 4 μg·100 ml tissue(-1)·min(-1)) were measured before and after endothelial NO synthase inhibition with N(G)-monomethyl-l-arginine (l-NMMA, 50 mg bolus + 1 mg/min infusion). The NO component of endothelium-dependent dilation was calculated as the response to ACh before and after l-NMMA accounting for changes in baseline FBF: [(FBF ACh - FBF baseline) - (FBF ACh(L-NMMA) - FBF baseline(L-NMMA))]. This value was 5.7 ± 1.3 and 2.5 ± 0.8 ml·100 ml forearm tissue(-1)·min(-1) for the low- and high-sodium diets, respectively (main effect of sodium, P = 0.019). The sodium effect was larger for the men, with values of 7.9 ± 2.0 and 2.2 ± 1.4 for men vs. 3.1 ± 1.3 and 2.7 ± 1.0 ml·100 ml forearm tissue(-1)·min(-1) for the women (P = 0.034, sex-by-sodium interaction). We conclude that the NO component of endothelium-dependent vasodilation is altered by dietary sodium intake based on sex, suggesting that endothelial NO production is sensitive to dietary sodium in healthy young men but not women.
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Affiliation(s)
- John H Eisenach
- Department of Anesthesiology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA.
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15
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Delaney LE, Arce-Esquivel AA, Kuroki K, Laughlin MH. Exercise training improves vasoreactivity in the knee artery. Int J Sports Med 2011; 33:114-22. [PMID: 22095322 DOI: 10.1055/s-0031-1291186] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Physical activity has been shown to enhance endothelial function of central and peripheral vascular beds. The primary purpose of the present study was to test the hypothesis that a short-term exercise training program would result in enhanced endothelium-dependent vasorelaxation of a major artery supplying blood flow to the knee joint, the middle genicular artery. Female Yucatan miniature swine were randomly assigned into exercise trained (n=7) or sedentary (n=7) groups. Exercise trained pigs underwent a daily exercise training program on treadmills for 7 days. In vitro assessment of vasorelaxation was determined in a dose response manner by administrating increasing doses of 3 different dilators; adenosine diphosphate, bradykinin, and sodium nitroprusside. The role of nitric oxide synthase and cyclooxygenase pathways in vasomotor responses was evaluated with specific inhibitors using nitro-L-arginine methyl ester and indomethacin incubation, respectively. The results of this investigation indicate that adenosine and bradykinin-induced endothelium-dependent vasorelaxation were significantly enhanced in middle genicular artery from exercise trained pigs (p<0.05). Endothelium-independent vasorelaxation was not altered with exercise training as determined by the response to sodium nitroprusside. The findings of the present investigation indicate that short-term exercise training enhances endothelial function of middle genicular artery through adaptations in the nitric oxide synthase and by non-nitric oxide synthase, non-cyclooxygenase pathways.
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Affiliation(s)
- L E Delaney
- Department of Biomedical Sciences, University of Missouri, Columbia 65203, United States
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16
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Casey DP, Joyner MJ. Prostaglandins do not contribute to the nitric oxide-mediated compensatory vasodilation in hypoperfused exercising muscle. Am J Physiol Heart Circ Physiol 2011; 301:H261-8. [PMID: 21536852 DOI: 10.1152/ajpheart.00222.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested the hypothesis that 1) prostaglandins (PGs) contribute to compensatory vasodilation in contracting human forearm subjected to acute hypoperfusion, and 2) the combined inhibition of PGs and nitric oxide would attenuate the compensatory vasodilation more than PG inhibition alone. In separate protocols, subjects performed forearm exercise (20% of maximum) during hypoperfusion evoked by intra-arterial balloon inflation. Each trial included baseline, exercise before inflation, exercise with inflation, and exercise after deflation. Forearm blood flow (FBF; ultrasound) and local (brachial artery) and systemic arterial pressure [mean arterial pressure (MAP); Finometer] were measured. In protocol 1 (n = 8), exercise was repeated during cyclooxygenase (COX) inhibition (Ketorolac) alone and during Ketorolac-NOS inhibition [N(G)-monomethyl-l-arginine (l-NMMA)]. In protocol 2 (n = 8), exercise was repeated during l-NMMA alone and during l-NMMA-Ketorolac. Forearm vascular conductance (FVC; ml·min(-1)·100 mmHg(-1)) was calculated from FBF (ml/min) and local MAP (mmHg). The percent recovery in FVC during inflation was calculated as (steady-state inflation + exercise value - nadir)/[steady-state exercise (control) value - nadir] × 100. In protocol 1, COX inhibition alone did not reduce the %FVC recovery compared with the control (no drug) trial (92 ± 11 vs. 100 ± 10%, P = 0.83). However, combined COX-nitric oxide synthase (NOS) inhibition caused a substantial reduction in %FVC recovery (54 ± 8%, P < 0.05 vs. Ketorolac alone). In protocol 2, the percent recovery in FVC was attenuated with NOS inhibition alone (69 ± 9 vs. 107 ± 10%, P < 0.01) but not attenuated further during combined NOS-COX inhibition (62 ± 10%, P = 0.74 vs. l-NMMA alone). Our data indicate that PGs are not obligatory to the compensatory dilation observed during forearm exercise with hypoperfusion.
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Affiliation(s)
- Darren P Casey
- Dept. of Anesthesiology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA.
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17
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Álvares TS, Meirelles CM, Bhambhani YN, Paschoalin VM, Gomes PS. L-Arginine as a Potential Ergogenic Aid in Healthy Subjects. Sports Med 2011; 41:233-48. [DOI: 10.2165/11538590-000000000-00000] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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18
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Padilla J, Simmons GH, Fadel PJ, Laughlin MH, Joyner MJ, Casey DP. Impact of aging on conduit artery retrograde and oscillatory shear at rest and during exercise: role of nitric oxide. Hypertension 2011; 57:484-9. [PMID: 21263118 DOI: 10.1161/hypertensionaha.110.165365] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Aging has been recently associated with increased retrograde and oscillatory shear in peripheral conduit arteries, a hemodynamic environment that favors a proatherogenic endothelial cell phenotype. We evaluated whether nitric oxide (NO) bioavailability in resistance vessels contributes to age-related differences in shear rate patterns in upstream conduit arteries at rest and during rhythmic muscle contraction. Younger (n=11, age 26 ± 2 years) and older (n=11, age 61 ± 2 years) healthy subjects received intra-arterial saline (control) and the NO synthase inhibitor N(G)-Monomethyl-L-arginine. Brachial artery diameter and velocities were measured via Doppler ultrasound at rest and during a 5-minute bout of rhythmic forearm exercise. At rest, older subjects exhibited greater brachial artery retrograde and oscillatory shear (-13.2 ± 3.0 s(-1) and 0.11 ± .0.02 arbitrary units, respectively) compared with young subjects (-4.8 ± 2.3 s(-1) and 0.04 ± 0.02 arbitrary units, respectively; both P<0.05). NO synthase inhibition in the forearm circulation of young, but not of older, subjects increased retrograde and oscillatory shear (both P<0.05), such that differences between young and old at rest were abolished (both P>0.05). From rest to steady-state exercise, older subjects decreased retrograde and oscillatory shear (both P<0.05) to the extent that no exercise-related differences were found between groups (both P>0.05). Inhibition of NO synthase in the forearm circulation did not affect retrograde and oscillatory shear during exercise in either group (all P>0.05). These data demonstrate for the first time that reduced NO bioavailability in the resistance vessels contributes, in part, to age-related discrepancies in resting shear patterns, thus identifying a potential mechanism for increased risk of atherosclerotic disease in conduit arteries.
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Affiliation(s)
- Jaume Padilla
- Department of Biomedical Sciences, University of Missouri, Columbia, MO 65211, USA.
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19
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Wray DW, Witman MAH, Ives SJ, McDaniel J, Fjeldstad AS, Trinity JD, Conklin JD, Supiano MA, Richardson RS. Progressive handgrip exercise: evidence of nitric oxide-dependent vasodilation and blood flow regulation in humans. Am J Physiol Heart Circ Physiol 2011; 300:H1101-7. [PMID: 21217074 DOI: 10.1152/ajpheart.01115.2010] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In the peripheral circulation, nitric oxide (NO) is released in response to shear stress across vascular endothelial cells. We sought to assess the degree to which NO contributes to exercise-induced vasodilation in the brachial artery (BA) and to determine the potential of this approach to noninvasively evaluate NO bioavailability. In eight young (25 ± 1 yr) healthy volunteers, we used ultrasound Doppler to examine BA vasodilation in response to handgrip exercise (4, 8, 12, 16, 20, and 24 kg) with and without endothelial NO synthase blockade [intra-arterial N(G)-monomethyl-L-arginine (L-NMMA), 0.48 mg · dl(-1) · min(-1)]. Higher exercise intensities evoked significant BA vasodilation (4-12%) that was positively correlated with the hyperemic stimulus (r = 0.98 ± 0.003, slope = 0.005 ± 0.001). During NO blockade, BA vasodilation at the highest exercise intensity was reduced by ∼70% despite similar exercise-induced increases in shear rate (control, +224 ± 30 s(-1); L-NMMA, +259 ± 46 s(-1)). The relationship and slope of BA vasodilation with increasing shear rate was likewise reduced (r = 0.48 ± 0.1, slope = 0.0007 ± 0.0005). We conclude that endothelial NO synthase inhibition with L-NMMA abolishes the relationship between shear stress and BA vasodilation during handgrip exercise, providing clear evidence of NO-dependent vasodilation in this experimental model. These results support this paradigm as a novel and valid approach for a noninvasive assessment of NO-dependent vasodilation in humans.
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Affiliation(s)
- D Walter Wray
- Division of Geriatrics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah 84148, USA.
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20
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Schrage WG, Wilkins BW, Johnson CP, Eisenach JH, Limberg JK, Dietz NM, Curry TB, Joyner MJ. Roles of nitric oxide synthase and cyclooxygenase in leg vasodilation and oxygen consumption during prolonged low-intensity exercise in untrained humans. J Appl Physiol (1985) 2010; 109:768-77. [PMID: 20558755 DOI: 10.1152/japplphysiol.00326.2010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The vasodilator signals regulating muscle blood flow during exercise are unclear. We tested the hypothesis that in young adults leg muscle vasodilation during steady-state exercise would be reduced independently by sequential pharmacological inhibition of nitric oxide synthase (NOS) and cyclooxygenase (COX) with NG-nitro-L-arginine methyl ester (L-NAME) and ketorolac, respectively. We tested a second hypothesis that NOS and COX inhibition would increase leg oxygen consumption (VO2) based on the reported inhibition of mitochondrial respiration by nitric oxide. In 13 young adults, we measured heart rate (ECG), blood pressure (femoral venous and arterial catheters), blood gases, and venous oxygen saturation (indwelling femoral venous oximeter) during prolonged (25 min) steady-state dynamic knee extension exercise (60 kick/min, 19 W). Leg blood flow (LBF) was determined by Doppler ultrasound of the femoral artery. Whole body VO2 was measured, and leg VO2 was calculated from blood gases and LBF. Resting intra-arterial infusions of acetylcholine (ACh) and nitroprusside (NTP) tested inhibitor efficacy. Leg vascular conductance (LVC) to ACh was reduced up to 53±4% by L-NAME+ketorolac infusion, and the LVC responses to NTP were unaltered. Exercise increased LVC from 4±1 to 33.1±2 ml.min(-1).mmHg(-1) and tended to decrease after L-NAME infusion (31±2 ml.min(-1).mmHg(-1), P=0.09). With subsequent administration of ketorolac LVC decreased to 29.6±2 ml.min(-1).mmHg(-1) (P=0.02; n=9). While exercise continued, LVC returned to control values (33±2 ml.min(-1).mmHg(-1)) within 3 min, suggesting involvement of additional vasodilator mechanisms. In four additional subjects, LVC tended to decrease with L-NAME infusion alone (P=0.08) but did not demonstrate the transient recovery. Whole body and leg VO2 increased with exercise but were not altered by L-NAME or L-NAME+ketorolac. These data indicate a modest role for NOS- and COX-mediated vasodilation in the leg of exercising humans during prolonged steady-state exercise, which can be restored acutely. Furthermore, NOS and COX do not appear to influence muscle VO2 in untrained healthy young adults.
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Plasma ATP concentration and venous oxygen content in the forearm during dynamic handgrip exercise. BMC PHYSIOLOGY 2009; 9:24. [PMID: 20003530 PMCID: PMC2801472 DOI: 10.1186/1472-6793-9-24] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Accepted: 12/15/2009] [Indexed: 11/30/2022]
Abstract
Background It has been proposed that adenosine triphosphate (ATP) released from red blood cells (RBCs) may contribute to the tight coupling between blood flow and oxygen demand in contracting skeletal muscle. To determine whether ATP may contribute to the vasodilatory response to exercise in the forearm, we measured arterialised and venous plasma ATP concentration and venous oxygen content in 10 healthy young males at rest, and at 30 and 180 seconds during dynamic handgrip exercise at 45% of maximum voluntary contraction (MVC). Results Venous plasma ATP concentration was elevated above rest after 30 seconds of exercise (P < 0.05), and remained at this higher level 180 seconds into exercise (P < 0.05 versus rest). The increase in ATP was mirrored by a decrease in venous oxygen content. While there was no significant relationship between ATP concentration and venous oxygen content at 30 seconds of exercise, they were moderately and inversely correlated at 180 seconds of exercise (r = -0.651, P = 0.021). Arterial ATP concentration remained unchanged throughout exercise, resulting in an increase in the venous-arterial ATP difference. Conclusions Collectively these results indicate that ATP in the plasma originated from the muscle microcirculation, and are consistent with the notion that deoxygenation of the blood perfusing the muscle acts as a stimulus for ATP release. That ATP concentration was elevated just 30 seconds after the onset of exercise also suggests that ATP may be a contributing factor to the blood flow response in the transition from rest to steady state exercise.
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22
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Lenasi H. The role of nitric oxide- and prostacyclin-independent vasodilatation in the human cutaneous microcirculation: effect of cytochrome P450 2C9 inhibition. Clin Physiol Funct Imaging 2009; 29:263-70. [DOI: 10.1111/j.1475-097x.2009.00862.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Nicholson WT, Vaa B, Hesse C, Eisenach JH, Joyner MJ. Aging is associated with reduced prostacyclin-mediated dilation in the human forearm. Hypertension 2009; 53:973-8. [PMID: 19414649 DOI: 10.1161/hypertensionaha.108.121483] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aging is associated with reduced endothelial function. There is indirect evidence for reduced prostacyclin (PGI(2))-mediated vasodilation with aging, but it is unknown whether this is because of reduced dilation to PGI(2) or altered production. In addition, the contribution of endothelial NO to PGI(2)-mediated dilation is unknown. Using plethysmography to determine forearm blood flow, we studied the effect of PGI(2) in 10 older (61 to 73 years) and 10 younger (19 to 45 years) subjects using 3 escalating intra-arterial doses of PGI(2) (epoprostenol). PGI(2) was also administered after NO synthase inhibition with N(G)-monomethyl-l-arginine acetate. The percent of change in forearm vascular conductance (mean+/-SEM) from baseline after PGI(2) was significantly lower (P=0.002) in the aging individuals (52+/-11%, 164+/-23%, and 221+/-27% versus 115+/-20%, 249+/-19%, and 370+/-35%). In addition, the group-by-dose interaction was also significant (P=0.018). After NO synthase inhibition, the dose-response curve to PGI(2) was blunted in the young subjects but unchanged in the older subjects; the difference between the groups was no longer significant. Our data suggest that the reduced dilator effects of PGI(2) in older individuals are attributable to a reduction in the contribution of endothelial-derived NO versus alterations in the direct effects of PGI(2) on vascular smooth muscle.
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Affiliation(s)
- Wayne T Nicholson
- Department of Anesthesiology, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA.
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Settergren M, Böhm F, Malmström RE, Channon KM, Pernow J. L-arginine and tetrahydrobiopterin protects against ischemia/reperfusion-induced endothelial dysfunction in patients with type 2 diabetes mellitus and coronary artery disease. Atherosclerosis 2009; 204:73-8. [PMID: 18849028 DOI: 10.1016/j.atherosclerosis.2008.08.034] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Revised: 08/29/2008] [Accepted: 08/29/2008] [Indexed: 11/20/2022]
Abstract
Diminished levels of L-arginine and endothelial nitric oxide synthase (eNOS) uncoupling through deficiency of tetrahydrobiopterin (BH(4)) may contribute to endothelial dysfunction. We investigated the effect of L-arginine and BH(4) administration on ischemia-reperfusion (I/R)-induced endothelial dysfunction in patients with type 2 diabetes and coronary artery disease (CAD). Forearm blood flow was measured by venous occlusion plethysmography in 12 patients with type 2 diabetes or impaired glucose tolerance and CAD. Forearm ischemia was induced for 20 min, followed by 60 min of reperfusion. The patients received a 15 min intra-brachial infusion of L-arginine (20 mg/min) and BH(4) (500 microg/min) or 0.9% saline starting at 15 min of ischemia on two separate study occasions. Compared with pre-ischemia the endothelium-dependent vasodilatation (EDV) induced by acetylcholine was significantly reduced at 15 and 30 min of reperfusion when saline was infused (P<0.001), but not following L-arginine and BH(4) infusion. EDV was also significantly less reduced at 15 and 30 min of reperfusion following L-arginine and BH(4) infusion, compared to saline infusion (P<0.02). Endothelium-independent vasodilatation (EIDV) induced by nitroprusside was unaffected by I/R. Venous total biopterin levels in the infused arm increased from 37+/-7 at baseline to 6644+/-1240 nmol/l during infusion of L-arginine and BH(4) (P<0.0001), whereas there was no difference in biopterin levels during saline infusion. In conclusion L-arginine and BH(4) supplementation reduces I/R-induced endothelial dysfunction, a finding which may represent a novel treatment strategy to limit I/R injury in patients with type 2 diabetes and CAD.
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Affiliation(s)
- M Settergren
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
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25
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The vascular effects of rotigaptide in vivo in man. Biochem Pharmacol 2008; 76:1194-200. [DOI: 10.1016/j.bcp.2008.08.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 08/12/2008] [Accepted: 08/18/2008] [Indexed: 11/22/2022]
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Dietze GJ, Henriksen EJ. Angiotensin-converting enzyme in skeletal muscle: sentinel of blood pressure control and glucose homeostasis. J Renin Angiotensin Aldosterone Syst 2008; 9:75-88. [PMID: 18584583 DOI: 10.3317/jraas.2008.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Recent evidence suggests a coordinated regulation by the local renin-angiotensin system (RAS) and tissue kallikrein-kinin system (TKKS) of blood flow and substrate supply in oxidative red myofibres of skeletal muscle tissue during endurance exercise. The performance of these myofibres is dependent on the increased oxidation of substrates facilitated by augmenting nutritive blood flow and glucose uptake. Humoral factors released by the contracting fibres, such as adenosine and kinins, are suggested to be responsible for this metabolic adjustment. The considerable drain of blood volume and the enormous consumption of glucose during endurance exercise require a control mechanism for the maintenance of blood pressure (BP) and glucose homeostasis. This is achieved by the sympathetic nervous system and its subordinate RAS, which is located in the nutritive vessels and parenchyma of the red myofibres. The angiotensin-converting enzyme (ACE) is the primary enzyme responsible for kinin degradation during exercise, underscoring the important interrelationship between the RAS and the TKKS in the critical role of kinins in the multifactorial regulation of muscle bioenergetics and glucose and BP homeostasis. Importantly, overactivity of the ACE, as occurs in individuals displaying risk factors such as overweight, causes exaggerated BP response and reduced glucose disposal. If they persist over years, compensatory responses to this ACE overactivity, such as hypersecretion of insulin and compliance of the vessel walls, will inevitably be exhausted, leading ultimately to the manifestation of type 2 diabetes and hypertension. This concept also provides a unifying explanation for the beneficial effects of ACE-inhibitors and Angiotensin II receptor antagonists in the treatment of hypertension and insulin resistance.
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Affiliation(s)
- Guenther J Dietze
- Hypertension and Diabetes Research Unit, Max Grundig Clinic, Buehl, Germany
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Newcomer SC, Taylor JC, McAllister RM, Laughlin MH. Effects of chronic nitric oxide synthase inhibition on endothelium-dependent and -independent relaxation in arteries that perfuse skeletal muscle of swine. ACTA ACUST UNITED AC 2008; 15:17-31. [PMID: 18568942 DOI: 10.1080/10623320802092211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The purpose of this investigation was to test the hypothesis that chronic N(G)-nitro-l-arginine methyl ester (l-NAME) treatment produces differential effects on conduit artery and resistance arteriole relaxation responses to endothelium-dependent and -independent vasodilators in arteries that perfuse skeletal muscle of swine. To test this hypothesis, conduit skeletal muscle arteries and second-order skeletal muscle (2A) arterioles were harvested from 14 Yucatan swine that were chronically administered l-NAME and from 16 controls. In vitro assessments of vasorelaxation to increasing doses of acetylcholine (ACH), bradykinin (BK), and sodium nitroprusside (SNP) were performed in both conduit and 2A arterioles. l-NAME treatment produced a significant reduction in both BK and ACH relaxation responses in the conduit arteries. In contrast, the relaxation response and/or sensitivity to SNP were significantly greater in the intact, but not denuded, conduit arterial rings from chronically l-NAME-treated swine. There were no significant effects of chronic l-NAME treatment on vasodilation of skeletal muscle arterioles. These findings suggest (1) that unlike arterioles, skeletal muscle conduit arteries do not functionally compensate for a lack of NO through the upregulation of alternative vasodilator pathways; (2) that the greater relaxation response in conduit arteries of chronically l-NAME-treated swine to SNP can be explained by alterations to the endothelium.
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Affiliation(s)
- S C Newcomer
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, USA
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Lenasi H, Strucl M. The effect of nitric oxide synthase and cyclooxygenase inhibition on cutaneous microvascular reactivity. Eur J Appl Physiol 2008; 103:719-26. [PMID: 18516617 DOI: 10.1007/s00421-008-0769-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2008] [Indexed: 10/22/2022]
Abstract
The role of nitric oxide (NO)- and prostacyclin (PGI(2))-independent mechanism, potentially attributable to endothelium-derived hyperpolarizing factor (EDHF), has not been extensively studied in human skin microcirculation. The aim of our study was to elucidate the contribution of the NO- and PGI(2)-independent mechanism to microvascular reactivity of cutaneous microcirculation. Skin perfusion was measured on the volar aspect of the forearm in 12 healthy male subjects (mean age 25.0 +/- 1.5), using laser Doppler (LD) fluxmetry. Combined endothelial nitric oxide synthase (eNOS) and cyclooxygenase (COX) inhibition was achieved by an intradermal injection (10 microl) of the eNOS inhibitor, L(omega)-monomethyl L-arginine (L-NMMA, 10 mM) and the COX inhibitor, diclofenac (10 mM); saline was injected as a control. LD flux was assessed at rest and after an iontophoretical application of acetylcholine (ACh, 1%), an endothelial agonist and sodium nitroprusside (SNP, 1%), an endothelium-independent agonist, respectively. Combined eNOS and COX inhibition had no effect on the baseline LDF (12.5 +/- 2.3 PU (perfusion units) in control vs. 10.9 +/- 1.8 PU in the treated site). On the other hand, the ACh-stimulated increase in LDF was significantly attenuated after eNOS and COX inhibition (390.5 +/- 43.5%), compared to the control (643.7 +/- 80.3% increase, t-test, P < 0.05). Nevertheless, at least 60% of ACh-mediated vasodilatation was preserved after combined eNOS and COX inhibition. eNOS and COX inhibition had no impact on the SNP-stimulated increase in LDF (768.8 +/- 70.5% in control vs. 733.5 +/- 54.6% in the treated site). These findings indicate that NO- and PGI(2)-independent mechanism plays an important role in the regulation of blood flow in the human skin microcirculation.
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Affiliation(s)
- Helena Lenasi
- Institute of Physiology, School of Medicine, University of Ljubljana, Zaloska 4, Ljubljana, Slovenia.
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Differential effects of glucose on agonist-induced relaxations in human mesenteric and subcutaneous arteries. Br J Pharmacol 2007; 153:480-7. [PMID: 18037911 DOI: 10.1038/sj.bjp.0707592] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND AND PURPOSE Acute periods of hyperglycaemia are strongly associated with vascular disorder, yet the specific effects of high glucose on human blood vessel function are not fully understood. In this study we (1) characterized the endothelial-dependent relaxation of two similarly sized but anatomically distinct human arteries to two different agonists and (2) determined how these responses are modified by acute exposure to high glucose. EXPERIMENTAL APPROACH Ring segments of human mesenteric and subcutaneous arteries were mounted in a wire myograph. Relaxations to acetylcholine and bradykinin were determined in a control (5 mM) and high glucose (20 mM) environment over a 2 and 6 h incubation period. KEY RESULTS Bradykinin-induced relaxation in both sets of vessels was mediated entirely by EDHF whilst that generated by acetylcholine, though principally generated by EDHF, also had contribution from prostacyclin and possibly nitric oxide in mesenteric and subcutaneous vessels, respectively. A 2-h incubation of high glucose impaired bradykinin-induced relaxation of subcutaneous vessels whilst, in contrast, the relaxation generated by bradykinin in mesenteric vessels was enhanced at the same time point. High glucose significantly augmented the relaxation generated by acetylcholine in mesenteric and subcutaneous vessels at a 2 and 6 h incubation point, respectively. CONCLUSIONS AND IMPLICATIONS Short periods of high glucose exert a variable influence on endothelial function in human isolated blood vessels that is dependent on factors of time, agonist-used and vessel studied. This has implications for how we view the effects of acute hyperglycaemia found in patients with diabetes mellitus as well as other conditions.
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Fitzgerald SM, Bashari H, Cox JA, Parkington HC, Evans RG. Contributions of endothelium-derived relaxing factors to control of hindlimb blood flow in the mouse in vivo. Am J Physiol Heart Circ Physiol 2007; 293:H1072-82. [PMID: 17468338 DOI: 10.1152/ajpheart.00072.2007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We determined the contributions of various endothelium-derived relaxing factors to control of basal vascular tone and endothelium-dependent vasodilation in the mouse hindlimb in vivo. Under anesthesia, catheters were placed in a carotid artery, jugular vein, and femoral artery (for local hindlimb circulation injections). Hindlimb blood flow (HBF) was measured by transit-time ultrasound flowmetry. N(omega)-nitro-L-arginine methyl ester (L-NAME, 50 mg/kg plus 10 mg x kg(-1) x h(-1)), to block nitric oxide (NO) production, altered basal hemodynamics, increasing mean arterial pressure (30 +/- 3%) and reducing HBF (-30 +/- 12%). Basal hemodynamics were not significantly altered by indomethacin (10 mg x kg(-1) x h(-1)), charybdotoxin (ChTx, 3 x 10(-8) mol/l), apamin (2.5 x 10(-7) mol/l), or ChTx plus apamin (to block endothelium-derived hyperpolarizing factor; EDHF). Hyperemic responses to local injection of acetylcholine (2.4 microg/kg) were reproducible in vehicle-treated mice and were not significantly attenuated by L-NAME alone, indomethacin alone, L-NAME plus indomethacin with or without co-infusion of diethlyamine NONOate to restore resting NO levels, ChTx alone, or apamin alone. Hyperemic responses evoked by acetylcholine were reduced by 29 +/- 11% after combined treatment with apamin plus charybdotoxin, and the remainder was virtually abolished by additional treatment with L-NAME but not indomethacin. None of the treatments altered the hyperemic response to sodium nitroprusside (5 microg/kg). We conclude that endothelium-dependent vasodilation in the mouse hindlimb in vivo is mediated by both NO and EDHF. EDHF can fully compensate for the loss of NO, but this cannot be explained by tonic inhibition of EDHF by NO. Control of basal vasodilator tone in the mouse hindlimb is dominated by NO.
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Affiliation(s)
- Sharyn M Fitzgerald
- Department of Physiology, Monash University, Melbourne, Victoria 3800, Australia
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Medow MS, Taneja I, Stewart JM. Cyclooxygenase and nitric oxide synthase dependence of cutaneous reactive hyperemia in humans. Am J Physiol Heart Circ Physiol 2007; 293:H425-32. [PMID: 17369458 PMCID: PMC4511470 DOI: 10.1152/ajpheart.01217.2006] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We tested the hypothesis that cyclooxygenases (COXs) or COX products inhibit nitric oxide (NO) synthesis and thereby mask potential effects of NO on reactive hyperemia in the cutaneous circulation. We performed laser-Doppler flowmetry (LDF) with intradermal microdialysis in 12 healthy volunteers aged 19-25 yr. LDF was expressed as the percent cutaneous vascular conduction (%CVC) or as the maximum %CVC (%CVC(max)) where CVC is LDF/mean arterial pressure. We tested the effects of the nonisoform-specific NO synthase inhibitor nitro-L-arginine (NLA, 10 mM), the nonspecific COX inhibitor ketorolac (Keto, 10 mM), combined NLA + Keto, and NLA + sodium nitroprusside (SNP, 28 mM) on baseline and reactive hyperemia flow parameters. We also examined the effects of isoproterenol, a beta-adrenergic agonist that causes prostaglandin-independent vasodilation to correct for the increase in baseline flow caused by Keto. When delivered directly into the intradermal space, Keto greatly augments all aspects of the laser-Doppler flow response to reactive hyperemia: peak reactive hyperemic flow increased from 41 +/- 5 to 77 +/- 7%CVC(max), time to peak flow increased from 17 +/- 3 to 56 +/- 24 s, the area under the reactive hyperemic curve increased from 1,417 +/- 326 to 3,376 +/- 876%CVC(max).s, and the time constant for the decay of peak flow increased from 100 +/- 23 to 821 +/- 311 s. NLA greatly attenuates the Keto response despite exerting no effects on baseline LDF or on reactive hyperemia when given alone. Low-dose NLA + SNP duplicates the Keto response. Isoproterenol increased baseline and peak reactive flow. These results suggest that COX inhibition unmasks NO dependence of reactive hyperemia in human cutaneous circulation.
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Affiliation(s)
- Marvin S Medow
- Department of Pediatrics, The Center for Pediatric Hypotension, New York Medical College, 19 Bradhurst Avenue, Hawthorne, NY 10532, USA
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32
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Morton JS, Jackson VM, Daly CJ, McGrath JC. Endothelium Dependent Relaxation in Rabbit Genital Resistance Arteries is Predominantly Mediated by Endothelial-Derived Hyperpolarizing Factor in Females and Nitric Oxide in Males. J Urol 2007; 177:786-91. [PMID: 17222682 DOI: 10.1016/j.juro.2006.09.072] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Indexed: 11/29/2022]
Abstract
PURPOSE In nongenital arteries a sex difference has been postulated in the dominant endothelium-derived relaxant factor(s), eg nitric oxide, prostacyclin or endothelial-derived hyperpolarizing factor. Knowledge of endothelium-derived relaxant factor mechanisms in genital tissues could influence the development of novel treatments for sexual dysfunction. We compared nitric oxide and endothelial-derived hyperpolarizing factor contributions to acetylcholine induced relaxation in the genital arteries of the 2 sexes. MATERIALS AND METHODS Male dorsal and cavernous penile arteries, and female extravaginal and intravaginal arteries from New Zealand White rabbits were studied. Acetylcholine concentration-vasodilator response curves were constructed in the presence of the nitric oxide synthase inhibitor Nomega-nitro-L-arginine methyl ester, K(+) channel blockers (apamin and charybdotoxin) or a combination. Indomethacin was present throughout to exclude prostacyclins. RESULTS Extravaginal artery relaxation was predominantly endothelial-derived hyperpolarizing factor induced. Apamin plus charybdotoxin decreased maximal relaxations from a mean +/- SEM of 77% +/- 4% to 23% +/- 3% in 6 preparations (p <0.01). However, nitric oxide and endothelial-derived hyperpolarizing factor contributed to overall function. Dorsal artery relaxation was largely nitric oxide induced. Nomega-nitro-L-arginine methyl ester decreased maximal relaxations from 90% +/- 3% to 41% +/- 9% (p <0.001) with no endothelial-derived hyperpolarizing factor involvement (p >0.05). In cavernous and intravaginal arteries nitric oxide and endothelial-derived hyperpolarizing factor contributed to acetylcholine induced relaxation, while nitric oxide predominated. Blocking nitric oxide synthase or K(+) channels indicated that myogenic tone and constitutive activity of endothelium-derived relaxant factors were present. Vasodilator nerve mediated responses were influenced by each with the former more effective. CONCLUSIONS Vaginal inflow arteries showed a dominance of endothelial-derived hyperpolarizing factor, contrasting with nitric oxide in penile arteries. Penile arteries followed the trend that endothelial-derived hyperpolarizing factor involvement increased with decreasing vessel caliber, while the reverse was demonstrated in female arteries.
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Abstract
The arterial vessels within the arms and legs are exposed to different hydrostatic pressures and blood-flow demands during the course of daily life. There is compelling indirect evidence that arterial reactivity differs in the arms and legs of humans; greater blood-flow responses to physiological vasodilator stimuli are generally reported in the arms of healthy younger subjects, whereas greater sympathetically mediated vasoconstrictor responsiveness is generally observed in the legs. Limb blood-flow responses to local arterial infusions of vasoactive agents reveal a similar pattern of heterogeneity in human arms versus legs. The advantages and assumptions of these pharmacological approaches for evaluating limb arterial reactivity are discussed, and methodological issues pertaining to the normalization and interpretation of vascular responses in the human arm and leg are critically examined. The article concludes with recent data from our laboratory indicating that limb-specific variation in arterial function may be age-, sex-, and physical activity dependent.
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Affiliation(s)
- David N Proctor
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802-6900, USA.
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Holowatz LA, Thompson CS, Minson CT, Kenney WL. Mechanisms of acetylcholine-mediated vasodilatation in young and aged human skin. J Physiol 2005; 563:965-73. [PMID: 15661816 PMCID: PMC1665610 DOI: 10.1113/jphysiol.2004.080952] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Thermoregulatory cutaneous vasodilatation (VD) is attenuated in aged skin. While acetylcholine (ACh) plays a role in thermally mediated VD, the precise mechanisms through which ACh-mediated VD acts and whether those downstream mechanisms change with ageing are unclear. We tested the hypotheses that both nitric oxide (NO)- and prostanoid-mediated pathways contribute to exogenous ACh-mediated VD, and that both are attenuated with advanced age. Twelve young (Y: 23 +/- 1 years) and 10 older (O: 69 +/- 1 years) subjects underwent infusions of 137.5 mum ACh at four intradermal microdialysis sites: control (C, Ringer solution), NO synthase inhibited (NOS-I, 10 mm l-NAME), cyclooxygenase inhibited (COX-I, 10 mm ketorolac) and NOS-I + COX-I. Red blood cell flux was monitored using laser-Doppler flowmetry, and cutaneous vascular conductance (CVC) was calculated (laser-Doppler flux/mean arterial pressure) and normalized to maximal CVC (%CVC(max)) (28 mm sodium nitroprusside + local heating to 43 degrees C). Baseline %CVC(max) was increased in the O at COX-I sites (COX-I 16 +/- 1, NOS-I + COX-I 16 +/- 2 versus C 10 +/- 1%CVC(max); P < 0.001) but not in the young, suggesting an age-related shift toward COX vasoconstrictors contributing to basal cutaneous vasomotor tone. There was no difference in peak %CVC(max) during ACh infusion between age groups, and the response was unchanged by NOS-I (O: NOS-I 35 +/- 5 versus C 38 +/- 5%CVC(max); P = 0.84) (Y: NOS-I 41 +/- 4 versus C 39 +/- 4%CVC(max); P = 0.67). COX-I and NOS-I + COX-I attenuated the peak CVC response to ACh in both groups (COX-I O: 29 +/- 3, Y: 22 +/- 2%CVC(max) versus C; P < 0.001 both groups; NOS-I + COX-I O: 32 +/- 3 versus Y: 29 +/- 2%CVC(max); versus C; P < 0.001 both groups). ACh mediates cutaneous VD through prostanoid and non-NO-, non-prostanoid-dependent pathways. Further, older subjects have a diminished prostanoid contribution to ACh-mediated VD.
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Affiliation(s)
- Lacy A Holowatz
- The Pennsylvania State University, Noll Laboratory, University Park, PA 16802, USA.
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