Recurrent administration of the nitric oxide donor, isosorbide dinitrate, induces a persistent cephalic cutaneous hypersensitivity: A model for migraine progression.

Background A subgroup of migraineurs experience an increase in attack frequency leading to chronic migraine. Methods We assessed in rats the roles of dose and repeat administration of systemic isosorbide dinitrate (ISDN), a nitric oxide donor, on the occurrence and development of cephalic/face and extracephalic/hindpaw mechanical allodynia as a surrogate of migraine pain, and the effect of acute systemic sumatriptan and olcegepant and chronic systemic propranolol on these behavioral changes. Results A single high (H-ISDN) but not low (L-ISDN) dose of ISDN induces a reversible cephalic and extracephalic mechanical allodynia. However, with repeat administration, L-ISDN produces reversible cephalic but never extracephalic allodynia, whereas H-ISDN induces cephalic and extracephalic allodynia that are both potentiated. H-ISDN-induced cephalic allodynia thus gains persistency. Sumatriptan and olcegepant block single H-ISDN-induced behavioral changes, but only olcegepant reduces these acute changes when potentiated by repeat administration. Neither sumatriptan nor olcegepant prevent chronic cephalic hypersensitivity. Conversely, propranolol blocks repeat H-ISDN-induced chronic, but not acute, behavioral changes. Conclusions Repeated ISDN administration appears to be a naturalistic rat model for migraine progression, suitable for screening acute and preventive migraine therapies. It suggests frequent and severe migraine attacks associated with allodynia may be a risk factor for disease progression.

The Endothelin Receptor Antagonist Macitentan Improves Isosorbide-5-Mononitrate (ISMN) and Isosorbide Dinitrate (ISDN) Induced Endothelial Dysfunction, Oxidative Stress, and Vascular Inflammation.

OBJECTIVE: Organic nitrates such as isosorbide-5-mononitrate (ISMN) and isosorbide dinitrate (ISDN) are used for the treatment of patients with chronic symptomatic stable coronary artery disease and chronic congestive heart failure. Limiting side effects of these nitrovasodilators include nitrate tolerance and/or endothelial dysfunction mediated by oxidative stress. Here, we tested the therapeutic effects of the dual endothelin (ET) receptor antagonist macitentan in ISMN- and ISDN-treated animals. METHODS AND RESULTS: Organic nitrates (ISMN, ISDN, and nitroglycerin (GTN)) augmented the oxidative burst and interleukin-6 release in cultured macrophages, whereas macitentan decreased the oxidative burst in isolated human leukocytes. Male C57BL/6j mice were treated with ISMN (75 mg/kg/d) or ISDN (25 mg/kg/d) via s.c. infusion for 7 days and some mice in addition with 30 mg/kg/d of macitentan (gavage, once daily). ISMN and ISDN in vivo therapy caused endothelial dysfunction but no nitrate (or cross-)tolerance to the organic nitrates, respectively. ISMN/ISDN increased blood nitrosative stress, vascular/cardiac oxidative stress via NOX-2 (fluorescence and chemiluminescence methods), ET1 expression, ET receptor signaling, and markers of inflammation (protein and mRNA level). ET receptor signaling blockade by macitentan normalized endothelial function, vascular/cardiac oxidative stress, and inflammatory phenotype in both nitrate therapy groups. CONCLUSION: ISMN/ISDN treatment caused activation of the NOX-2/ET receptor signaling axis leading to increased vascular oxidative stress and inflammation as well as endothelial dysfunction. Our study demonstrates for the first time that blockade of ET receptor signaling by the dual endothelin receptor blocker macitentan improves adverse side effects of the organic nitrates ISMN and ISDN.

The nitric oxide donor, isosorbide dinitrate, induces a cephalic cutaneous hypersensitivity, associated with sensitization of the medullary dorsal horn.

Nitric oxide donors are known to produce headache in healthy as well as migraine subjects, and to induce extracephalic cutaneous hypersensitivity in rodents. However, little is known on the effect of nitric oxide donors on cephalic cutaneous sensitivity. Combining behavioral, immunohistochemical, and in vivo electrophysiological approaches, this study investigated the effect of systemic administration of the nitric oxide donor, isosorbide dinitrate (ISDN), on cephalic and extracephalic cutaneous sensitivity and on neuronal activation within the medullary dorsal horn (MDH) in the rat. Systemic administration of ISDN increased selectively the first phase and interphase of the facial formalin test, but had no effect on the hindpaw formalin one. Monitoring neuronal activity within the MDH with phospho-ERK1/2 immunoreactivity revealed that ISDN alone did not activate MDH neurons, but significantly increased the number of formalin-evoked phospho-ERK1/2-immunoreactive cells in the ipsilateral, but not contralateral, MDH. Using in vivo electrophysiological unit recordings, we show that ISDN administration never affected the spontaneous activity of trigeminal wide dynamic range neurons, but, facilitated C-fiber-evoked responses in half the neurons tested. This research demonstrates that a nitric oxide donor, isosorbide dinitrate, induces selectively cephalic hyperalgesia that arises as a consequence of central sensitization in pain pathways that subserve meningeal nociception. This model better mimics the clinical condition and offers another possibility of studying the role of nitric oxide donor in the physiopathology of headache.

Towards a pragmatic human migraine model for drug testing: 2. Isosorbide-5-mononitrate in healthy individuals.

Background A model for the testing of novel anti-migraine drugs should preferably use healthy volunteers for ease of recruiting. Isosorbide-5-mononitrate (5-ISMN) provokes headache in healthy volunteers with some migraine features such as pulsating pain quality and aggravation by physical activity. Therefore, this headache might respond to sumatriptan, a requirement for validation of any model. The hypothesis of the present study was that sumatriptan is effective in 5-ISMN-induced headache in healthy individuals. Methods In a double-blind, randomised, crossover design, 30 healthy volunteers of both sexes received 5-ISMN 60 mg on two separate days, each day followed by oral self-administered placebo or sumatriptan 50 mg. Headache response and accompanying symptoms were registered in a questionnaire by the participants themselves. Results 5-ISMN induced a reproducible headache in all 30 participants. The headache had several migraine-like features in all participants and 20 individuals developed a migraine-like attack. Median peak headache score was 5 on both experimental days ( p = 1.00). There was no reduction, but instead an increase in headache intensity 2 hours after sumatriptan ( p = 0.003). Difference in area under the headache score curve (AUC) 0-4 hours between sumatriptan and placebo was not significant ( p = 0.30). Conclusion 5-ISMN is a very powerful inducer of migraine-like headache in healthy individuals but the headache does not respond to sumatriptan. The model is not useful for future drug testing.

Chronic therapy with isosorbide-5-mononitrate causes endothelial dysfunction, oxidative stress, and a marked increase in vascular endothelin-1 expression.

AIMS: Isosorbide-5-mononitrate (ISMN) is one of the most frequently used compounds in the treatment of coronary artery disease predominantly in the USA. However, ISMN was reported to induce endothelial dysfunction, which was corrected by vitamin C pointing to a crucial role of reactive oxygen species (ROS) in causing this phenomenon. We sought to elucidate the mechanism how ISMN causes endothelial dysfunction and oxidative stress in vascular tissue. METHODS AND RESULTS: Male Wistar rats (n= 69 in total) were treated with ISMN (75 mg/kg/day) or placebo for 7 days. Endothelin (ET) expression was determined by immunohistochemistry in aortic sections. Isosorbide-5-mononitrate infusion caused significant endothelial dysfunction but no tolerance to ISMN itself, whereas ROS formation and nicotinamide adenine dinucleotidephosphate (NADPH) oxidase activity in the aorta, heart, and whole blood were increased. Isosorbide-5-mononitrate up-regulated the expression of NADPH subunits and caused uncoupling of the endothelial nitric oxide synthase (eNOS) likely due to a down-regulation of the tetrahydrobiopterin-synthesizing enzyme GTP-cyclohydrolase-1 and to S-glutathionylation of eNOS. The adverse effects of ISMN were improved in gp91phox knockout mice and normalized by bosentan in vivo/ex vivo treatment and suppressed by apocynin. In addition, a strong increase in the expression of ET within the endothelial cell layer and the adventitia was observed. CONCLUSION: Chronic treatment with ISMN causes endothelial dysfunction and oxidative stress, predominantly by an ET-dependent activation of the vascular and phagocytic NADPH oxidase activity and NOS uncoupling. These findings may explain at least in part results from a retrospective analysis indicating increased mortality in post-infarct patients in response to long-term treatment with mononitrates.

Comparison of vasorelaxant effect and tolerance profile of a novel isosorbide-5-mononitrate derivative with its stereoisomer and parent drug on rat mesenteric artery.

BACKGROUND/AIMS: 5-Ketoximeisosorbide-2-mononitrate (50-IS-2-MN) was synthesized and its pharmacological and toxicological characteristics were examined and compared with its parent drug, isosorbide-5-mononitrate (IS-5-MN, CAS 16051-77-7), and its diastereoisomer 2-ketoximeisosorbide-5-mononitrate. METHODS: Vasorelaxation was studied on phenylephrine-precontracted rat superior mesenteric artery rings in organ bath procedure. In some rings, the endothelium was mechanically removed. In vitro tolerance was induced by treating the precontracted rings with maximal concentrations of the parent drug and the ketoximes, and after washing out, the procedure was repeated for two times. Furthermore, rats were treated with a single oral dose (1000 mg/kg) of 50-IS-2-MN and 20-IS-5-MN. RESULTS: After a phenylephrine-induced contraction, 50-IS-2-MN (10(-8)-10(-4) mol/l) caused a concentration-dependent relaxation of the rat superior mesenteric artery that was strongly potentiated after the removal of the vascular endothelium. In preparations with or without endothelium, 50-IS-2-MN was a more potent relaxant than either the parent compound or its isomer. The mechanism of the relaxant effect of 50-IS-2-MN involves the activated soluble guanylyl cyclase-cyclic GMP pathway. Hydralazine (10(-5) mol/l), a strong antioxidant, ameliorated tolerance to IS-5-MN, but did not affect the absence of tolerance to either ketoxime. The minimum lethal dose in rat for 5O-IS-2-MN and 20-IS-5-MN was greater than 1000 mg/kg. CONCLUSION: These results suggest that the modification of the configuration at the ester carbon of IS-5-MN contributes to more potent and tolerance-devoid activity on the rat superior mesenteric artery.

Curative isosorbide-5-mononitrate treatment, in opposition to the beneficial preventive one, aggravates the prothrombotic and proconstrictor state in cyclosporine-induced hypertensive rats.

1. The aim of the present study was to evaluate the effect of preventive and curative isosorbide-5-mononitrate (Is-5-Mn) treatment on the development of hypertension, cGMP content, thromboxane (TX) A(2)/prostaglandin (PG) I2 balance, the peripheral serotonergic system, platelet activation, lipid peroxidation and plasma lipids in cyclosporine A (CsA)-induced hypertensive rats. 2. Control, CsA (5 mg/kg per day) and Is-5-Mn (150 mg/kg per day, b.i.d.) rat groups were treated orally over a period of 7 weeks. The preventive Is-5-Mn group (Is-5-Mn + CsA) was first treated for 2 weeks with Is-5-Mn, followed by 7 weeks with both drugs; the curative Is-5-Mn group (CsA + Is-5-Mn) was treated for a period of 7 weeks with CsA and with both drugs for an additional 5 weeks. The control group received oral vehicle. 3. Whereas in the group undergoing preventive treatment the CsA-induced increase in blood pressure (BP), compared with the control group, was avoided, in the group undergoing curative treatment, the increase in BP was even higher. The decreased arterial cGMP content in the CsA group was prevented and reverted when Is-Mn was administered either preventatively or curatively with CsA. Platelet TXA2 production, although unaffected in the Is-5-Mn + CsA group, was significantly higher in the CsA + Is-5-Mn group compared with the group receiving CsA alone. Furthermore, plasma TXA2 was reduced following preventive Is-5-Mn treatment, but was worsened in the group undergoing curative therapy. Aortic PGI2 synthesis was identical in all groups. Consequently, the TXA2/PGI2 ratio was only altered in the CsA + Is-5-Mn group, demonstrating a markedly higher value. In both groups treated simultaneously with CsA and Is-5-Mn, a higher platelet 5-hydroxytryptamine (5-HT) content was obtained compared with CsA treatment alone, but only preventive treatment with Is-5-Mn resulted in a significant reduction in plasma 5-HT. Changes in ADP and collagen-induced platelet aggregation paralleled those of plasma 5-HT and TXA2: the hyperaggregation profile of the CsA group, although partially prevented, was not reverted by simultaneous treatment with Is-5-Mn and CsA. Lipid peroxidation and lipid profile values also worsened in the CsA + Is-5-Mn group compared with the group administered CsA alone. 4. In conclusion, the beneficial effects of concomitant Is-5-Mn and CsA treatment were demonstrated when Is-5-Mn was administered preventatively because not only was arterial hypertension prevented, but platelet aggregation and plasma TXA2 and 5-HT levels were also reduced. In contrast, following curative treatment, the BP, platelet/vascular vasoconstrictor balance, lipid peroxidation and plasma lipids were aggravated, recommending a judicious evaluation of the impact of nitrate therapy throughout the period of its administration.

Comparison of proarrhythmogenic effects of two potassium channel openers, levcromakalim (BRL 38227) and nicorandil (RP 46417): a high-resolution mapping study on rabbit heart.

This study was designed (a) to test and (b) to compare proarrhythmic effects of levcromakalim and nicorandil; and (c) determine the mechanism of arrhythmia initiation by using high-resolution ventricular epicardial mapping on 44 Langendorff-perfused rabbit hearts. Eighteen hearts were kept intact and received incremental doses (1-500 microM) of levcromakalim, nicorandil, and isosorbide dinitrate. In 26 hearts, a thin layer of epicardium was obtained after endocardial cryotechnique (frozen hearts). In intact hearts, isosorbide dinitrate did not produce any arrhythmia. In contrast, levcromakalim induced spontaneous ventricular fibrillation (VF) in all hearts at 50 microM, whereas only one VF occurred at 500 microM nicorandil. These three drugs produced a dose-dependent bradycardia in intact hearts. In frozen hearts, arrhythmias were induced by 5 microM levcromakalim and 50 microM nicorandil. Isosorbide dinitrate had no proarrhythmogenic effect. Epicardial mapping showed that most of induced ventricular tachycardias were based on reentry around an arc of functional conduction block. Ventricular conduction velocities did not change, but levcromakalim and nicorandil shortened ventricular effective refractory period. We conclude that (a) levcromakalim and nicorandil, used in toxic concentrations, have direct proarrhythmic effects; (b) nicorandil proarrhythmogenic effects are 10 times less marked than those of levcromakalim (arrhythmia is solely the result of the potassium channel opener property of nicorandil); and (c) most of ventricular tachycardias induced are based on reentry.

Nitric oxide-generating vasodilators and 8-bromo-cyclic guanosine monophosphate inhibit mitogenesis and proliferation of cultured rat vascular smooth muscle cells.

Endothelium-derived relaxing factor has been recently identified as nitric oxide. The purpose of this study was to determine if vasodilator drugs that generate nitric oxide inhibit vascular smooth muscle mitogenesis and proliferation in culture. Three chemically dissimilar vasodilators, sodium nitroprusside, S-nitroso-N-acetylpenicillamine and isosorbide dinitrate, dose-dependently inhibited serum-induced thymidine incorporation by rat aortic smooth muscle cells. Moreover, 8-bromo-cGMP mimicked the antimitogenic effect of the nitric oxide-generating drugs. The antimitogenic effect of S-nitroso-N-acetylpenicillamine was inhibited by hemoglobin and potentiated by superoxide dismutase, supporting the view that nitric oxide was the ultimate effector. Sodium nitroprusside and S-nitroso-N-acetylpenicillamine significantly decreased the proliferation of vascular smooth muscle cells. Moreover, the inhibition of mitogenesis and proliferation was shown to be independent of cell damage, as documented by several criteria of cell viability. These results suggest that endogenous nitric oxide may function as a modulator of vascular smooth muscle cell mitogenesis and proliferation, by a cGMP-mediated mechanism.

New isosorbide 5-mononitrate derivative with hypotensive activity.

Synthesis and pharmacological properties of the 5-fluoro-nicotinic ester with isosorbide-5-mononitrate 3 are reported. The new compound shows an in vitro activity on rabbit aortic helical strips five times higher than isosorbide-5-mononitrate. The hypotensive activity in guinea-pigs of 3 is markedly superior to that of 5-ISMN. In the rat 3 shows a bioavailability and an acute toxicity inferior to those of 5-ISMN after oral administration.

Oral isosorbide-5-mononitrate: pharmacokinetics and clinical efficacy.

Isosorbide-5-mononitrate is a longer acting active metabolite than the parent drug, isosorbide dinitrate (ISDN), with a half-life of around 4 hours. In coronary heart disease, myocardial infarction and in heart failure it causes a typical nitrate action on the central hemodynamics, but due to a complete systemic availability with high and predictable systemic drug levels, a drug action with a lower interindividual variability than with ISDN is to be expected. There is a close correlation between serum level and effect. The antianginal exercise tolerance increasing and unwanted effects as well as the development of tolerance to the drug action are comparable with those of ISDN. This naturally long-acting metabolite in ISDN works usually with a standard dosage of 20 mg twice daily.

Cardiorespiratory effects of isosorbide dinitrate and nifedipine in combination with nadolol: a double-blind comparative study of beneficial and adverse antianginal drug interactions.

Combinations of 2 or 3 drugs are often used to treat angina pectoris, but their combined cardiorespiratory effects have not been investigated. Using a randomized, double-blind, placebo-controlled protocol, the effects of nadolol alone and nadolol in combination with isosorbide dinitrate and nifedipine were compared, in low and high doses, on antianginal efficacy, respiratory functions and arterial blood oxygen saturation (SaO2) in 19 patients with stable angina pectoris. A complete assessment including a bicycle exercise test with the measurement of the sum of ST-segment depression in all leads (sigma ST) was carried out every 2 weeks. The frequency of anginal attacks and nitroglycerin consumption was reduced significantly (p less than 0.001) by nadolol alone and in combination with the other drugs. Nadolol caused a slight reduction in the forced expiratory volume in 1 second, which was improved by isosorbide dinitrate and nifedipine. The sigma ST profile (basal, at peak exercise and 2 and 5 minutes after exercise) was decreased by nadolol alone and in combination with the other drugs, although the greatest reduction was achieved with large doses of nifedipine and nadolol. The rest and postexercise SaO2 decreased after nadolol alone and in combination with isosorbide dinitrate, but recovered to pretrial values after nifedipine and nadolol. With all drug combination, sigma ST depression was greater when the postexercise SaO2 was less than 92%, and decreased (p less than 0.05) in the same patients when their postexercise SaO2 was greater than 92%.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in the nitrite ion formation and the toxicological findings between isosorbide dinitrate and isosorbide-5-mononitrate.

In the metabolism of isosorbide dinitrate (ISDN), fast denitration with the formation of nitrite ions and a mononitrate plays an important role. In contrast, the denitration of isosorbide-5-mononitrate (IS-5-MN) to isosorbide is very slow. Accordingly po administration of high doses of ISDN (92.5 and 236 mg/kg) in conscious dogs led to maximum nitrite concentrations in the blood of 0.9 and 3.3 mg/liter, respectively. In contrast, with equimolar doses of IS-5-MN (75 and 191 mg/kg) we were able to detect nitrite ions reliably only at the higher dose and this gave a maximum blood concentration of 0.4 mg/liter. The rise in nitrite ion concentration is followed by the formation of methemoglobin. As is known from the literature, there is a rise in the activity of alkaline phosphatase in the serum of rabbits in addition to methemoglobin formation following repeated administration of sodium nitrite. So we have specifically investigated whether this is also the case following ISDN and IS-5-MN administration. On po administration of 236 mg/kg ISDN/day to dogs, there was a continuous rise in alkaline phosphatase from about the 20th day onward which we did not observe after the equimolar dose of IS-5-MN (191 mg/kg). NaNO2, 35 mg/kg po, led to a comparable maximal rise in methemoglobin to that obtained with 236 mg/kg ISDN. Repeated po administration of 35 mg/kg NaNO2/day also caused a rise in alkaline phosphatase. It is concluded that the formation of nitrite ions from ISDN is the reason for the rise in methemoglobin and alkaline phosphatase. The lower formation of nitrite ions from IS-5-MN can also be of clinical importance, at least in certain cases.

Chromosome aberrations induced by clinical medicines.

Inducibility of chromosome aberrations of cultured mammalian cells was examined on 11 clinical medicines which are used for a long term mainly in the field of internal medicine. P-aminosalicilic acid, isonicotinic acidhydrazid, streptomycin A, hydralazine hydrochloride methimazole and theophylline induced definite increase of chromosome aberrations. Among them P-aminosalicilic acid was a little weak in its effect. The effects of rifamycin SV, aminophylline and isosorbide dinitrate were judged as suspicious, because only a slight increase of the aberrations were caused. Reserpine and propylthiouracil induced little chromosome aberrations. Effective concentrations of these medicines in our chromosome test were compared with their maximum blood concentrations in clinical use in human quoted from the published papers. Their ratios by isonicotinic acid hydrazid, streptomycin A, methimazole, theophylline and issorbide dinitrate were very high and those by others were relatively low. Because p-aminosalicilic acid, rifamycin SV, hydralazine hydrochloride and aminophylline were positive or suspicious in our chromosome test, further pursue for the safety evaluation seems necessary.