1

PCTH 400

Drugs that improve endothelial function.

Pascal N. Bernatchez, AssociateProfessor 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

2

Endothelial dysfunction causes hypertension and vice-versa

EC dysfunction

Which one comes first?

Atherosclerosis

Arteriosclerosis

Hypertension

Macrophage accumulation Formation of

necrotic coreFormation of

fibrous cap

R.Ross, N.Engl.J.Med., 1999

Atherosclerosis

3

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

4

Diuretics?

Endothelial dysfunction causes hypertension and vice-versa

EC dysfunction

Which one comes first?

Atherosclerosis

Arteriosclerosis

Hypertension

5

-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?

6

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?

8

Revatio

-Has anyone heard of Revatio? -Used to treat pulmonary hypertension

Revatio

Revatio

cGMP

Mechanism of action?

9

Revatio and Viagra

Revatio Viagra

Nitroglycerin

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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 system

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Angiotensin II

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

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Angiotensin II and Oxidative stress

AT1vsAT2

Angiotensin II and Oxidative stress

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Angiotensin II

ACEi Increase NO function indirectly (less AngII oxidative stress) and directly (Bradykinin)

AngII inhibitors and direct effect on endothelial function

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Angiotensin II

Angiotensin II and Oxidative stress

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Statins

-Inhibit HMGCoA Reductase -Extremely controversial (why?) -Upcoming Lecture

Vascular Medicine

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.

Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01013103.(Circulation. 2011;124:335-345.)

Key Words: statins ! tetrahydrobiopterin ! oxidative stress ! superoxide ! nitric oxide synthase

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,

Oxford, UK. E-mail keith.channon@cardiov.ox.ac.uk© 2011 American Heart Association, Inc.

Circulation is available at http://circ.ahajournals.org DOI: 10.1161/CIRCULATIONAHA.110.985150

335

‘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

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Polyphenols

62.2 ± 8.6 years; P, NS), number of diseased vessels(2.1 ± 0.95 versus 2.3 ± 0.95; P, NS), ejection fraction(53.3 ± 17 versus 52.4 ± 14.7%; P, NS), lipids andcardiovascular risk factors (Table 2) and type of medica-tion (Table 3). Baseline artery diameter, baseline FMD,and flow at rest and hyperemic response did not differsignificantly between the two groups (Table 4). After theingestion of the RGPE there was an increase in FMDthroughout the study which peaked at 60 min and wassignificantly higher at that stage from the baseline level(P < 0.001) (Table 4). In addition, the 60 min value ofFMD after the ingestion of the RGPE was higher than thecorresponding value at 60 min after the intake of water(P < 0.001) (Fig. 1). There was no change in brachialdiameter before cuff inflation throughout the study. Afterthe ingestion of water there were no significant changes inFMD or hyperemic response at 30, 60 or 120 min. Finally,nitroglycerin-mediated dilatation was similar in bothgroups (8.4 ± 3.6 versus 8.5 ± 3.2%; P NS).

DiscussionThe presented data show that polyphenols obtained fromred grapes improve FMD acutely in men with documen-ted CHD. This is the first study to confirm this favorableeffect by the consumption of a red grape extract withpolyphenols being the only active components.

Previous studies indirectly proposed the same effect ofpolyphenols on endothelium. It was shown that acuteingestion of de-alcoholized red wine increases FMD inhealthy subjects and it was hypothesized that the non-alcoholic components of red wine, most likely polyphe-nols, are responsible for this effect [16,18,19]. In anotherstudy [20] short-term ingestion of purple grape juice, richin flavonoids (polyphenol derivatives), improved FMDand reduced susceptibility of low-density lipoprotein tooxidation in CHD patients. In-vitro data suggest that theeffect of purple grape juice on endothelial function maybe mediated through the production of nitric oxide[11,21,22]. It has been proposed that the critical step forthe activation of nitric oxide synthase is the increase ofintracellular free calcium [23]. Recently, incubation of

Table 2 Lipids and cardiovascular risk factors in the studiedsubgroups

Variable RGPE group Placebo group P

Total cholesterol (mg/dl) 212.7 ± 28 214.6 ± 38 NSLDL cholesterol (mg/dl) 135.5 ± 30 136.7 ± 39 NSTriglycerides (mg/dl) 155.9 ± 48.9 162.4 ± 48.5 NSHDL cholesterol (mg/dl) 41 ± 7 40 ± 6 NSSystolic BP (mmHg) 128.4 ± 12 126.2 ± 16.8 NSDiastolic BP (mmHg) 81.6 ± 15 78.9 ± 11 NSDiabetes mellitus (%) 26.7 20 NSSmoking (%) 40 33.3 NSBody mass index (kg/m2) 28 ± 3.2 27.9 ± 4.2 NSFamily history for CHD (%) 33.3 26.7 NS

RGPE, red grapes polyphenol extract; LDL, low-density lipoprotein; HDL, high-density lipoprotein; BP, blood pressure; CHD, coronary heart disease.

Table 3 Medication in the studied subgroups

Drug RGPE group Placebo group P

Statins (%) 60 60 NSNitrates (%) 46.7 40 NSACE inhibitors (%) 46.7 46.7 NSBeta-blockers (%) 66.7 53.3 NSAT1-antagonists (%) 13.3 6.7 NSCalcium blockers (%) 20 13.3 NS

RGPE, red grapes polyphenol extract; ACE, angiotensin-converting enzyme; AT1,angiotension II type 1.

Table 4 Vessel diameter at rest, flow at rest, hyperemia and flow mediated dilatation at baseline and after the ingestion of the extract of redgrapes or placebo

Baseline 30 min 60 min 120 min

Ingestion of red grape extract (n = 15)Diameter size at rest (mm) 4.78 ± 0.5 4.67 ± 0.45 4.7 ± 0.44 4.71 ± 0.48Flow at rest (ml/min) 152.6 ± 51 135 ± 62 151 ± 68 139 ± 54Hyperemia (%) 190 ± 96 235 ± 105 225 ± 110 235 ± 141FMD (%) 2.6 ± 1.5 3.73 ± 2.1 4.52 ± 1.34* 4.1 ± 2.6

Ingestion of placebo (n = 15)Diameter size at rest (mm) 4.5 ± 0.28 4.6 ± 0.28 4.58 ± 0.3** 4.5 ± 0.37Flow at rest (ml/min) 107 ± 67 109 ± 57 114 ± 59 140 ± 78Hyperemia (%) 257 ± 78 278 ± 107 274 ± 123 248 ± 123FMD (%) 2.75 ± 1.85 2.62 ± 1.65 2.64 ± 1.8 2.73 ± 1.8

FMD, flow-mediated dilatation. *P < 0.001 versus baseline. **P < 0.001 versus corresponding FMD at 60 min after the ingestion of the extract of red grapes.

Fig. 1

Baseline0.0

1.0

2.0

3.0FM

D (%

) 4.0

5.0

6.0

30

∗

∗∗

60 120Time (min)

Extract from red grapesPlacebo

Flow-mediated dilatation (FMD) at baseline, 30, 60, and 120 min afterthe ingestion of the extract of red grapes or placebo. *P < 0.001 versusbaseline; **P < 0.001 versus corresponding FMD at 60 min after theingestion of the extract of red grapes.

598 European Journal of Cardiovascular Prevention and Rehabilitation 2005, Vol 12 No 6

Copyright © European Society of Cardiology. Unauthorized reproduction of this article is prohibited. at University of British Columbia Library on October 1, 2014cpr.sagepub.comDownloaded from

Lekakis et al, Eur J Card Prev Rhabil

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