NO is the “hero” molecule of the last few decades. It is a ubiquitous and omnipotent radical with both hemodynamic and antiproliferative effects within the cardiovascular system. NO is an important counterregulatory factor for vasoconstrictors and growth promoting substances. Endothelial dysfunction with decreased NO production is related to many cardiovascular disorders, such as coronary artery disease, heart failure and hypertension. Despite the important role of NO within the circulation, there is only limited evidence in the form of large clinical trials that NO delivery can reduce cardiovascular morbidity and mortality. Thus, NO donors are not in the first line therapy in ischemic heart disease, heart failure or arterial hypertension and NO delivery is recommended only in particular clinical situations, when a well established treatment is contraindicated or has an insufficient effect. It is concluded that the insufficient NO production is the principal disorder in endothelial dysfunction, which is related to cardiovascular pathology with deteriorated prognosis, but the impact of therapeutically increased NO bioactivity on the morbidity and mortality is inferior to well established treatment with ACE-inhibitors, AT1 receptor blockers, beta-blockers, statins and certain antihypertensive drugs. There is little doubt that NO is king in the circulation, but kings seldom decide the battles., Fedor Šimko., and Obsahuje bibliografii
To investigate lisinopril effect on the contribution of nitric oxide (NO) and KCa channels to acetylcholine (ACh)-induced relaxation in isolated mesenteric arteries of spontaneously hypertensive rats (SHRs). Third branch mesenteric arteries isolated from lisinopril treated SHR rats (20 mg/kg/day for ten weeks, SHR-T) or untreated (SHR-UT) or normotensi ve WKY rats were mounted on tension myograph and ACh concentration-response curves were obtained. Westernblotting of eNOS and K Ca channels was performed. ACh-induced relaxations were similar in all groups while L-NMMA and indomethacin caused significant rightward shift only in SHR-T group. Apamin and TRAM-34 (SKCa and IKCa channels blockers, respectively) significantly attenuated ACh-induced maximal relaxation by similar magnitude in vessels from all three groups. In the presence of L-NMMA, indomethacin, apamin and TRAM-34 further attenuated ACh-induced relaxation only in SHR-T. Furthermore, lisinopril treatment increased expression of eNOS, SKCa and BKCa proteins. Lisinopril treatment increased expression of eNOS, SKCa , BKCa channel proteins and increased the contribution of NO to ACh-mediated relaxation. This increased role of NO was apparent only when EDHF component was blocked by inhibiting SKCa and IKCa channels. Such may suggest that in mesenteric arteries, non-EDHF component functions act as a reserve system to provide compensatory vasodilatation if (and when) hyperpolarization that is mediated by SKCa and IKCa channels is reduced, S. Albarwani, S. Al-Siyabi, I. Al-Husseini, A. Al-Ismail, I. Al-Lawati, I. Al-Bahrani, M. O. Tanira., and Obsahuje bibliografii
We aimed to explore the effects of melatonin and n-3 polyunsaturated fatty acids (PUFA) supplementation on plasma and aortic nitric oxide (NO) levels in isoproterenol (Iso) affected spontaneously hypertensive (SHR) and Wistar rats. Untreated control rats were compared with Iso injected (118 mg/kg, s.c.) rats, and Iso injected plus supplemented with melatonin (10 mg/kg, p.o.) or PUFA (1.68 g/kg, p.o.) for two months. Plasma and aortic basal, L-NAME inhibited, adrenaline and acetylcholine stimulated NO were determined using Griess method. Plasma NO levels were lower in SHR versus Wistar rats. Iso decreased NO in Wistar while not in SHR. PUFA but not melatonin intake of Iso treated SHR increased plasma NO along with a decrease in systolic blood pressure. Basal aortic NO level was higher in SHR than Wistar rats and not altered by Iso. Intake of melatonin increased but PUFA decreased basal NO levels in Wistar+Iso and did not affect in SHR+Iso rats. Acetylcholine and adrenaline induced aortic NO release was significantly increased in Wistar+Iso but not SHR+Iso group. Melatonin intake increased Ach induced aortic NO in Wistar+Iso and SHR+Iso groups, whereas there was no effect of PUFA intake. Findings suggest that PUFA modulates plasma and melatonin aortic NO levels of isoproterenol affected rats in a strain-dependent manner., K. K. Chaudagar, C. Viczenczova, B. Szeiffova Bacova, T. Egan Benova, M. Barancik, N. Tribulova., and Obsahuje bibliografii
Using histochemical analysis (NADPH-diaphorase, Fluoro-Jade B dye and bis-benzimide 33342 Hoechst) we studied the influence of intraperitoneal administration of nicotine (NIC), kainic acid (KA) and combination of both these substances on hippocampal neurons and their changes. In experiments, 35-day-old male rats of the Wistar strain were used. Animals were pretreated with 1 mg /kg of nicotine 30 min prior to the kainic acid application (10 mg/kg). After two days, the animals were transcardially perfused with 4 % paraformaldehyde under deep thiopental anesthesia. Cryostat sections were stained to identify NADPH-diaphorase positive neurons that were then quantified in the CA1 and CA3 areas of the hippocampus, in the dorsal and ventral blades of the dentate gyrus and in the hilus of the dentate gyrus. Fluoro-Jade B positive cells were examined in the same areas in order to elucidate a possible neurodegeneration. In animals exposed only to nicotine the number of NADPH-diaphorase positive neurons in the CA3 area of the hippocampus and in the hilus of the dentate gyrus was higher than in controls. In contrast, KA administration lowered the number of NADPH-diaphorase positive cells in all studied hippocampal areas and in both blades of the dentate gyrus. Massive cell degeneration was observed in CA1 and CA3 areas of the hippocampus and in the hilus of the dentate gyrus after kainic acid administration. Animals exposed to kainic acid and pretreated with nicotine exhibited degeneration to a lesser extent and the number of NADPH-diaphorase positive cells was higher compared to rats, which were exposed to kainic acid only., V. Riljak, M. Milotová, K. Jandová, J. Pokorný, M. Langmeier., and Obsahuje bibliografii a bibliografické odkazy
Nitric oxide (NO) is an important endogenous mediator with significant role in the respiratory system. Many endogenous and exogenous factors influence the synthesis of NO and its level is significantly changed during the inflammation. Analysis of nasal nitric oxide (nNO) is not validated so far as the diagnostic method. There is a lack of reference values with possible identification of factors modulating the nNO levels. In healthy adult volunteers (n=141) we studied nasal NO values by NIOX MINO® (Aerocrine, Sweden) according to the recommendations of the ATS & ERS. Gender, age, height, body weight, waist-to-hip ratio, FEV1/FVC, PEF and numbers of le ukocytes, eosinophils, basophils and monocytes were studied as potential variables influencing the levels of nNO. The complexity of the results allowed us to create a homogenous group for nasal NO monitoring and these data can be used further as the reference data for given variables. Because of significant correlation between nNO and exhaled NO, our results support the "one airway - one disease" concept. Reference values of nasal NO and emphasis of the individual parameters of tested young healthy population may serve as a starting point in the non-invasive monitoring of the upper airway inflammation., M. Antosova, D. Mokra, I. Tonhajzerova, P. Mikolka, P. Kosutova, M. Mestanik, L. Pepucha, J. Plevkova, T. Buday, V. Calkovsky, A. Bencova., and Obsahuje bibliografii
Nitric oxide (NO) is implicated in a wide variety of biological roles. NO is generated from three nitric oxide synthase (NOS) isoforms: neuronal (nNOS), inducible (iNOS), and endothelial (eNOS) all of which are found in the lung. While there are no isoform-specific inhibitors of NOS, the recent development and characterization of mice deficient in each of the NOS isoforms has allowed for more comprehensive study of the importance of NO in the lung circulation. Studies in the mouse have identified the role of NO from eNOS in modulating pulmonary vascular tone and in attenuating the development of chronic hypoxic pulmonary hypertension., K. A. Fagan, I. McMurtry, D. M. Rodman., and Obsahuje bibliografii
There are two principal mechanisms of acetylcholine (ACh) release from the resting motor nerve terminal: quantal and non-quantal (NQR); the former being only a small fraction of the total, at least at rest. In the present article we summarize basic research about the NQR that is undoubtedly an important trophic factor during endplate development and in adult neuromuscular contacts. NQR helps to eliminate the polyneural innervation of developing muscle fibers, ensures higher excitability of the adult subsynaptic membrane by surplus polarization and protects the RMP from depolarization by regulating the NO cascade and chloride transport. It shortens the endplate potentials by promoting postsynaptic receptor desensitization when AChE is inhibited during anti-AChE poisoning. In adult synapses, it can also activate the electrogenic Na+/K+-pump, change the degree of synchronization of quanta released by the nerve stimulation and affects the contractility of skeletal muscles., F. Vyskočil, A. I. Malomouzh, E. E. Nikolsky., and Obsahuje seznam literatury
This study sought to evaluate whether consumption of polyphenol extract from Cognac (CPC) modulates platelet activation and cardiovascular reactivity in rats. Male Wistar rats were treated daily for 4 weeks by intra-gastric gavage receiving CPC at 80 mg/kg/day or vehicle (5 % glucose). Platelet adhesion and aggregation in response to different activators were assessed. Cardiac and vascular reactivity in response to various agonists as well as NO measurement by electron paramagnetic resonance technique were investigated in isolated heart and thoracic aorta. Oral administration of CPC decreased platelet aggregation induced by ADP but not by collagen. CPC did not affect adhesion to collagen. The chronotropic but not the inotropic response to isoprenaline was reduced without alteration of NO production in hearts from CPC-treated rats. CPC treatment did not affect ex vivo relaxation to acetylcholine nor NO content of rat aorta. CPC did not significantly alter the response to phenylephrine in aorta despite the participation of endothelial vasoconstrictor products. In summary, chronic treatment with CPC has no impact on ex vivo vascular and cardiac reactivity; however, it reduced heart work and platelet aggregation. These data suggest the existence of compounds in Cognac that may decrease the risk of coronary thrombosis and protect against some cardiac diseases., N. Carusio, R. Wangensteen, A. Filippelli, R. Andriantsitohaina., and Obsahuje bibliiografii a bibliografické odkazy
This review concerns the role of nitric oxide (NO) in the pathogenesis of different models of experimental hypertension (NO-deficient, genetic, salt-dependent), which are characterized by a wide range of etiology. Although the contribution of NO may vary between different models of hypertension, a unifying characteristic of these models is the presence of oxidative stress that participates in the maintenance of elevated arterial pressure and seems to be a common denominator underlying endothelial dysfunction in various forms of experimental hypertension. Besides the imbalance between the endothelial production of vasorelaxing and vasoconstricting compounds as well as the relative insufficiency of vasodilator systems to compensate augmented vasoconstrictor systems, there were found numerous structural and functional abnormalities in blood vessels and heart of hypertensive animals. The administration of antihypertensive drugs, antioxidants and NO donors is capable to attenuate blood pressure elevation and to improve morphological and functional changes of cardiovascular system in some but not all hypertensive models. The failure to correct spontaneous hypertension by NO donor administration reflects the fact that sympathetic overactivity plays a key role in this form of hypertension, while NO production in spontaneously hypertensive rats might be enhanced to compensate increased blood pressure. A special attention should be paid to the modulation of sympathetic nervous activity in central and peripheral nervous system. These results extend our knowledge on the control of the balance between NO and reactive oxygen species production and are likely to be a basis for the development of new approaches to the therapy of diseases associated with NO deficiency., J. Török., and Obsahuje bibliografii a bibliografické odkazy