PCTH 400 Drugs that improve endothelial function. Pascal N. Bernatchez, Assistant Professor iCAPTURE Research Centre Dept. Anesthesiology, Pharmacology & Therapeutics University of British Columbia LAST LECTURE Providence Heart + Lung Institute at St. Paul’s Hospital University of British Columbia High blood pressure Blood pressure control Atherosclerosis Endothelial Injury Thrombus CABG PTCA Stent Drug eluting stents Classic Vascular pharmacology -chronic -systemic Local Vascular pharmacology -acute -targeted Patient burden Restenosis In-sent restenosis Lipid lowering drugs Platelet/SMC pharmacology Endothelial dysfunction causes hypertension and vice-versa EC dysfunction Which one comes first? Atherosclerosis Arteriosclerosis Hypertension Macrophage accumulation Formation of necrotic core Formation of fibrous cap R.Ross, N.Engl.J.Med., 1999 Atherosclerosis
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PCTH 400 3 of 7 endothelial function...-All have been shown to reverse endothelial dysfunction in coronary of patients -Poor clinical outcomes -Polyphenols: -French paradox, Mediterranean
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PCTH 400
Drugs that improve endothelial function.
Pascal N. Bernatchez, Assistant Professor iCAPTURE Research Centre
Dept. Anesthesiology, Pharmacology & Therapeutics University of British Columbia
LAST LECTURE
Providence Heart + Lung Institute at St. Paul’s Hospital
University of British Columbia
High blood pressure
Blood pressure control
Atherosclerosis Endothelial Injury
Thrombus
CABG
PTCA
Stent
Drug eluting stents
Classic Vascular pharmacology -chronic -systemic
Local Vascular pharmacology -acute -targeted
Patient burden
Restenosis
In-sent restenosis
Lipid lowering drugs Platelet/SMC pharmacology
Endothelial dysfunction causes hypertension and vice-versa
EC dysfunction
Which one comes first?
Atherosclerosis
Arteriosclerosis
Hypertension
Macrophage accumulation Formation of
necrotic core Formation of
fibrous cap
R.Ross, N.Engl.J.Med., 1999
Atherosclerosis
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Arteriosclerosis
-Hardening of arteries -Consequence of atherosclerosis + calcification -Hypertension -Endothelial dysfunction -MI -Aortic aneurysm -Stroke
Endothelium
Endothelium SMC
Nitric Oxide
Prostacyclin
EDHF
Superoxide
-Improve the bioavailability/release/ mimic of endothelial mediators -Decrease oxidative stress -Increase/potentiate the downstream effect
Diuretics?
Endothelial dysfunction causes hypertension and vice-versa
EC dysfunction
Which one comes first?
Atherosclerosis
Arteriosclerosis
Hypertension
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-First β-blocker to get FDA approval for heart failure -Improves LV function, used in hypertension and heart failure -Anti-oxidant activities: Long term months (no acute activities). Several metabolites of carvedilol (which have been found in human plasma) exhibit a much greater antioxidant activity than carvedilol itself (up to 50 times more activity)
Carvedilol
Effects of Carvedilol Versus Metoprolol on Endothelial Function and Oxidative Stress in Patients With Type 2 Diabetes Mellitus*, AmJHypertension
Pharmacology of NO
What is the most profitable drug of all time?
Viagra
-Sildenafil (UK-92,480) was synthesized by Pfizer in England. It was initially studied for use in hypertension (high blood pressure) and angina pectoris (ischaemic cardiovascular disease). -Year?
Structure of Viagra
Viagra
cGMP
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Mechanism of action
-Mechanism: 1- parasympathetic nervous system causes NO release in the corpus cavernosum and leads to increased inflow of blood and erection. 2- selective inhibitor of cGMP specific phosphodiesterase type 5 which is responsible for degradation of cGMP in the corpus cavernosum.
Revatio
Has anyone heard of Revatio?
Revatio
-Has anyone heard of Revatio? -Used to treat pulmonary hypertension
Revatio
Revatio
cGMP
Mechanism of action?
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Revatio and Viagra
Revatio Viagra
Nitroglycerin
Nitroglycerin
Angina (mostly stable or unstable?) Severe hypertension Myocardial infarction Do not use with viagra or revatio Workers? Murrell - 1879 He had unwittingly touched the moist cork stopper of a vial of nitroglycerin to his tongue while seeing outpatients.This caused a severe, pounding headache, tachycardia and a dramatic increase in the force of his heart beat.
W. B. Fye: William Murrell 427
Fir;. 1 William Murrell(1853-1912). Photograph provided by the National Library of Medicine, Bethesda, Maryland.
useful in treating patients with angina? His interest in organic nitrates can be traced to the observations of the Scottish physi- cian and pharmacologist T. Lauder Brunton? A pioneer of car- diovascular pharmacology, Brunton was the first to propose vasodilator as a treatment for angina. He advocated amyl ni- trate for the treatment of complaint in 1867.’ Earlier experi- ments had led medical scientists to classify this substance as a vasodilator that acted on the vasomotor nerves.
Brunton knew that some patients with angina seemed to im- prove with phlebotomy, and he thought that amyl nitrite might accomplish the same result without causing anemia. Soon af- ter Brunton published his findings in the Lancet, other physi- cians confirmed his observations and my1 nitrate became a standard remedy for angina. Although Brunton studied nitro- glycerin before Murrell experimented with it, he did not ad- minister it to humans because it gave him such a severe head- ache he thought patients would not tolerate
Murrell was not deterred. He thought nitroglycerin might be useful, in angina because the two drugs seemed to have the same effect on the circulation. Murrell’s theory was supported
by his early experience with the drug. He began administering nitroglycerin to patients with angina in the summer of 1878. His first patient was a 64-year-old heavy smoker with symp- toms consistent with angina. After ingesting a 1 % solutions of nitroglycerin three times a day for a week, the patient reported that the anginal attacks occurred less frequently and were less severe. Murrell did not depend solely on his patient’s subjec- tive impressions. He used the sphygmograph, an instrument recently invented for graphically recording the pulse, to docu- ment the drug’s effects on the heart rate and pulse wave form.
The special role of nitroglycerin in the treatment of angina pectoris was acknowledged rapidly. British physician William Green claimed in 1 882, “I am not overstating [nitroglycerin’s] merits when I say it deserves to rank only second to digitalis in the treatment of disease of the heart.”9 The liquid nitroglycerin preparation Murrell prescribed was inconvenient, however. Within a year the drug was available in tablet form in a variety of strengths. Anticipating the logical concern about the explo- sive potential of nitroglycerin, British chemist William Martindale explained that it was stable and “perfectly inexplo- sive-it cannot be detonated.”’O
In addition to his classic work on nitroglycerin, which was reprinted in book form in 1882, Murrell published mono- graphs on several other subjects including the treatment of bronchitis, the medical value of massage, and toxicology. He diedin 1912.
References
1. Fye WB: Nitroglycerin: A homeopathic remedy. Circulation 73,
2. Smith E, Hart FLl: William Murrell, physician and practical thera- pist. Br Med 53,632433 ( 1 971)
3. Murrell W: Nitro-glycerine as a remedy for angina pectoris. Lancet
4. Fye WB: Vasodilator therapy for angina pectoris: The intersection of homeopathy and scientific medicine. J Hist Med Allied Sci 45,
5. Murrell W Nitm-glycerine. ( 1 879) 8 I 6. Fye WB: T. Lauder Brunton and amyl nitrite: A Victorian vastdila-
tor. Circulation 74,222-229 ( 1986) 7. Brunton TL: On the use of nitrite of amyl in anginapectoris. Lancet
8. Brunton TL, Tait ES: Preliminary notes on the physiological action of nitroglycerin [ 18761. In Collected Papers on Circuhtion and Respiration. Fir.st Series. Macmillan & Co., London (1907) 22CL339
9. Green WG: Notes on the use of nitro-glycerine in the treatment of heart disease. Ther Guz 6,304-306 ( 1882) 304
10. Martindale W Nitroglycerin in pharmacy. Practitioner 24,35-39 (1880)37
21-29 (1986)
I , 8CL8l,113-ll5,151-152,225-227 (1879)
3 17-340 (1990)
2,97-98 (1 867)
Angiotensin II
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Angiotensin II
-AngII has a direct negative effect on endothelial function: -Decreases eNOS levels
-AngII has an indirect negative effect on endothelial function:
-Oxidative stress -AngII has a direct effect on blood pressure:
-SMC Constriction -AngII has a indirect effect on blood pressure:
-oxidative stress
Angiotensin II and Oxidative stress
AT1vsAT2
Angiotensin II and Oxidative stress
Angiotensin II
ACEi Increase NO function indirectly and directly
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AngII inhibitors and direct effect on endothelial function
Rapid, Direct Effects of Statin Treatment on Arterial RedoxState and Nitric Oxide Bioavailability in Human
Atherosclerosis via Tetrahydrobiopterin-MediatedEndothelial Nitric Oxide Synthase Coupling
Charalambos Antoniades, MD, PhD; Constantinos Bakogiannis, MD; Paul Leeson, PhD;Tomasz J. Guzik, PhD; Mei-Hua Zhang, PhD; Dimitris Tousoulis, MD, PhD;
Alexios S. Antonopoulos, MD; Michael Demosthenous, MD; Kyriakoula Marinou, MD, PhD; Ashley Hale;Andreas Paschalis, MD; Costas Psarros, BSc; Costas Triantafyllou, MD; Jennifer Bendall, PhD;
Barbara Casadei, MD, DPhil; Christodoulos Stefanadis, MD, PhD; Keith M. Channon, MD, FRCP
Background—Treatment with statins improves clinical outcome, but the exact mechanisms of pleiotropic statin effects onvascular function in human atherosclerosis remain unclear. We examined the direct effects of atorvastatin ontetrahydrobiopterin-mediated endothelial nitric oxide (NO) synthase coupling in patients with coronary artery disease.
Methods and Results—We first examined the association of statin treatment with vascular NO bioavailability and arterialsuperoxide (O2
·!) in 492 patients undergoing coronary artery bypass graft surgery. Then, 42 statin-naı̈ve patientsundergoing elective coronary artery bypass graft surgery were randomized to atorvastatin 40 mg/d or placebo for 3 daysbefore surgery to examine the impact of atorvastatin on endothelial function and O2
·! generation in internal mammaryarteries. Finally, segments of internal mammary arteries from 26 patients were used in ex vivo experiments to evaluatethe statin-dependent mechanisms regulating the vascular redox state. Statin treatment was associated with improvedvascular NO bioavailability and reduced O2
·! generation in internal mammary arteries. Oral atorvastatin increasedvascular tetrahydrobiopterin bioavailability and reduced basal and N-nitro-L-arginine methyl ester–inhibitable O2
·! ininternal mammary arteries independently of low-density lipoprotein lowering. In ex vivo experiments, atorvastatinrapidly improved vascular tetrahydrobiopterin bioavailability by upregulating GTP-cyclohydrolase I gene expressionand activity, resulting in improved endothelial NO synthase coupling and reduced vascular O2
·!. These effects werereversed by mevalonate, indicating a direct effect of vascular hydroxymethylglutaryl-coenzyme A reductase inhibition.
Conclusions—This study demonstrates for the first time in humans the direct effects of statin treatment on the vascular wall,supporting the notion that this effect is independent of low-density lipoprotein lowering. Atorvastatin directly improves vascular NObioavailability and reduces vascular O2
·! through tetrahydrobiopterin-mediated endothelial NO synthase coupling. These findingsprovide new insights into the mechanisms mediating the beneficial vascular effects of statins in humans.
Statins are now considered a fundamental component ofthe treatment of patients with atherosclerotic vascular
disease.1 Reducing low-density lipoprotein (LDL) cholesterolby statins reduces cardiovascular risk in both primary1 andsecondary2 prevention and is associated with improvementsin other markers of vascular disease risk, including inflam-mation and endothelial function.3,4
Clinical Perspective on p 345
In addition to LDL lowering, statins have been demonstratedto exert a number of pleiotropic effects.5–7 Reduction of LDL bystatin therapy appears to confer a greater reduction of cardio-vascular risk than LDL lowering by other modalities,8 andclinical trials demonstrate that statin treatment improves
Received August 20, 2010; accepted May 2011.From the Department of Cardiovascular Medicine, University of Oxford, NIHR Biomedical Research Centre, John Radcliffe Hospital, Oxford, UK
(C.A., P.L., M.-H.Z., A.H., J.B., B.C., K.M.C.); First Department of Cardiology, University of Athens, Hippokration Hospital, Athens, Greece (C.A.,C.B., D.T., A.S.A., M.D., K.M., A.P., C.P., C.S.); Department of Medicine, Jagiellonian University, Krakow, Poland (T.J.G., A.P.); and Department ofCardiac Surgery, Hippokration Hospital, Athens, Greece (C.T., A.P.).
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/CIRCULATIONAHA.110.985150/DC1.Correspondence to Keith M. Channon, MD, FRCP, Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital OX3 9DU,
Circulation is available at http://circ.ahajournals.org DOI: 10.1161/CIRCULATIONAHA.110.985150
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‘This study demonstrates for the first time in humans the direct effects of statin treatment on the vascular wall, supporting the notion that this effect is independent of low-density lipoprotein lowering. Atorvastatin directly improves vascular NO bioavailability and reduces vascular O(2)(·-)’ July 2011
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Food supplement
-Vitamin C: Increase eNOS activity and decrease NADPH oxidase activity. Increases eNOS cofactor activity -Vitamin E: Best anti-oxidant, but elusive activity -All have been shown to reverse endothelial dysfunction in coronary of patients -Poor clinical outcomes -Polyphenols: -French paradox, Mediterranean diet 1992
-50% lower CVD than North America -apples, blackberries, blueberries, cantaloupe, cherries, cranberries, grapes, pears, plums, raspberries, strawberries, vegetables, red wine, chocolate, green tea, olive oil -resveratrol
Polyphenols
-2 glasses a day (men) -1 glass a day (women) -Reduce oxidative stress -Reduces LDL oxidation -Increases HDL -Resveratrol supplements
LAST LECTURE
Providence Heart + Lung Institute at St. Paul’s Hospital