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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The endothelium plays an important role in the control of human vascular tone by releasing endothelium-derived nitric oxide. Therefore, endothelial dysfunction could be involved in the increased peripheral vasoconstriction of patients with chronic congestive heart failure (CHF). To investigate endothelial function in humans in vivo, agents such as acetylcholine are used to stimulate the release of endothelium-derived nitric oxide (EDRF). Conversely, N-mono-methyl-L-arginine (L-NMMA), a specific inhibitor of nitric oxide synthesis from L-arginine decreases forearm blood flow by inhibiting the basal release of nitric oxide. Consistent with experimental studies, the blood flow response to acetylcholine is blunted in patients with chronic heart failure as compared to healthy age-matched volunteers. In contrast, the decrease in blood flow induced by L-NMMA appears to be exaggerated in CHF. The blood flow response to nitroglycerin or sodium nitroprusside, endothelium-independent vasodilators, is usually preserved in patients with chronic, non-edematous heart failure, indicating a normal response of the vascular smooth muscle of resistance vessels to exogenous nitric oxide. In contrast, the dilator response of the radial artery diameter to nitroglycerin and flow-dependent dilation are impaired in patients with chronic heart failure, indicating that the abnormal flow-mediated relaxation of large arteries may be due to both endothelial and vascular smooth muscle alterations. Thus, impaired endothelium-dependent dilation of peripheral resistance vessels emerges in chronic heart failure, suggesting a reduced release of nitric oxide upon stimulation. Thus, endothelial dysfunction may be involved in the impaired vasodilator capacity in the peripheral circulation, e.g. during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Endothelial dysfunction in chronic heart failure. Experimental and clinical studies. 818 23

There is evidence that the endothelium plays an important role in the control of human vascular tone by releasing endothelium-derived nitric oxide and, therefore, a defective endothelial function could be involved in the increased peripheral vasoconstriction of patients with chronic congestive heart failure. To investigate endothelial function in humans in vivo, agents such as acetylcholine, a short-acting stimulator of the release of endothelium-derived nitric oxide, has been used. Conversely, N-mono-methyl-L-arginine, a specific inhibitor of nitric oxide synthesis from L-arginine, has recently been shown to decrease blood flow during infusion into the brachial artery of healthy volunteers (control subjects) by inhibiting the basal release of nitric oxide. Consistent with experimental studies, the blood flow response to acetylcholine is blunted in patients with chronic heart failure compared with healthy age-matched volunteers. In contrast, the decrease in blood flow induced by N-mono-methyl-L-arginine appears to be exaggerated in congestive heart failure. The blood flow response to nitroglycerin or sodium nitroprusside, endothelium-independent vasodilators, is usually preserved in patients with chronic, nonedematous heart failure, indicating a normal response of the vascular smooth muscle of resistance vessels to exogenous nitric oxide. In contrast, the dilator response of the radial artery diameter to nitroglycerin and flow-dependent dilation is impaired in patients with chronic heart failure, indicating that the abnormal flow-mediated relaxation of large arteries may be caused by both endothelial and structural abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Endothelial function in congestive heart failure. 836 50

Atrial natriuretic factor (ANF) promotes natriuresis and diuresis, increases vascular permeability and may induce peripheral vasodilatation. Endothelium-derived relaxing factor (EDRF), which is nitric oxide (NO), promotes local vasodilatation. ANF and EDRF-NO both cause vascular relaxation by generating cGMP via the activation of the particulate and soluble guanylate cyclases, respectively. This study examines the in vivo effect of exogenous ANF administration in normal Wistar rats, and of increased endogenous ANF in an experimental model of heart failure, on plasma and tissue cGMP concentrations. Low-dose ANF increased plasma and pulmonary cGMP concentrations, whereas 10-fold higher doses were necessary to increase aorta cGMP concentrations. Rats with a myocardial infarction had increased plasma ANF and cGMP and pulmonary cGMP concentrations, but aorta cGMP concentration remained similar to that of sham-operated rats. NG nitro L-arginine methyl ester (L-NAME) was administered chronically to sham-operated and myocardial infarction rats to block NO-synthase: soluble guanylate cyclase activity. L-NAME did not lower the increase in plasma ANF concentration or in urinary, plasma or pulmonary cGMP concentration. In contrast, L-NAME reduced the aorta cGMP concentration 6-fold, despite an increased level of circulating ANF. In summary, the pathophysiological range of plasma ANF concentrations greatly increases plasma and pulmonary cGMP concentrations (by activating particulate guanylate cyclase), but has little influence on the aorta cGMP concentration (which remains mainly dependent on NO-synthase: soluble guanylate cyclase activity).
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PMID:Atrial natriuretic factor influences in vivo plasma, lung and aortic wall cGMP concentrations differently. 839 39

The effect of L-arginine, 250 mg/kg over 10 min, on hemodynamics and venous function was studied in nine splenectomized dogs under light pentobarbital anesthesia before and after 17 +/- 1 days of rapid right ventricular pacing (RRVP) at 250 beats/min. Chronic RRVP induced mild congestive heart failure with increased mean circulatory filling (Pmcf), right atrial (Pra) and pulmonary capillary wedge pressures (Ppcw), and reduced cardiac output (CO). During the development of heart failure, total vascular compliance assessed from Pmcf-blood volume relationships during circulatory arrest was unchanged, but total vascular capacitance was markedly reduced, with an increase in stressed and reduction in unstressed blood volumes. At baseline but not after RRVP, L-arginine increased CO and reduced pulmonary vascular resistance. There were no significant changes in Pra, Ppcw, or total peripheral resistance. L-Arginine failed to alter total vascular compliance and capacitance or central blood volume in the baseline or failure state. These results do not support the hypothesis that increased Pmcf and reduced total vascular capacitance in the early stages of pacing-induced heart failure are caused by reduced substrate availability for or an endogenous competitive antagonist of NO synthase in venous endothelial cells.
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PMID:Acute effect of L-arginine on hemodynamics and vascular capacitance in the canine pacing model of heart failure. 858 82

Nitric oxide (NO) has been reported to mediate several effects in response to muscarinic cholinergic stimulation in cardiovascular tissues. Recently, an attenuation of guinea pig cardiac myocyte contraction by NO has been described. The aim of the present study was to determine whether the indirect negative inotropic effect of M-cholinoceptor stimulation in human myocardium is in part due to an effect of endogenous NO. Therefore, the effect of carbachol was studied under control conditions and during inhibition of NO-synthase by pretreatment with NG-monomethyl-L-arginine (NMMA). Functional experiments were performed in isolated, electrically driven (1 Hz, 37 degrees C) left ventricular papillary muscle strips of human myocardium. Since cytokines have been reported to be increased in the serum of patients with heart failure and could induce NO-synthase activity in failing myocardium, we compared samples from nonfailing and terminally failing (classified as NYHA IV) hearts. The indirect negative inotropic effect of carbachol (10 mumol/l) was studied in the presence of the beta-adrenoceptor agonist isoprenaline (0.03 mumol/l). After stimulation with isoprenaline, carbachol significantly (P < 0.05) reduced force of contraction. This effect was diminished in failing myocardium compared to nonfailing, probably due to the diminished inotropic response most likely due to the lower cAMP levels in response to beta-adrenoceptor stimulation in the former condition. Pretreatment with NMMA (100 mumol/l) altered the antiadrenergic effect of carbachol neither in nonfailing nor in failing preparations. Furthermore, inhibition of guanylyl cyclase, the target enzyme of NO, by preincubation with methylene blue (10 mumol/l) for 30 min had no effect on the carbachol-induced decrease in force of contraction.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Evidence against a role of nitric oxide in the indirect negative inotropic-effect of M-cholinoceptor stimulation in human ventricular myocardium. 858 47

We hypothesized that in cardiac muscles, angiotensin II partially inhibits the contractile response to beta-agonists. We studied the contractile response of isolated rat left ventricular papillary muscles to isoproterenol and the effect of angiotensin II on this response. We also investigated whether the effect of angiotensin II is mediated by bradykinin, prostaglandins, nitric oxide, and/or cGMP. Contractility of isolated papillary muscles was recorded with a force transducer, and rest tension, maximal developed tension (DT), maximal rate of rise in developed tension [T(+)], and maximal velocity of relaxation [T(-)] were measured (1) under basal conditions, (2) after pretreatment with various drugs, and (3) after cumulative doses of isoproterenol. Pretreatment groups included (1) vehicle (controls); (2) angiotensin II; (3) angiotensin II and N(omega)-nitro-L-arginine, an inhibitor of nitric oxide release; (4) L-arginine, the substrate for nitric oxide synthase; (5) L-arginine and N(omega)-nitro-L-arginine; (6) 8-bromo-cGMP, analogous to the second messenger of nitric oxide; (7) angiotensin II and icatibant (Hoe 140), a bradykinin B2 antagonist; and (8) angiotensin II and indomethacin, a cyclooxygenase inhibitor. There were no differences in contractile parameters before and after any of the pretreatments. Isoproterenol increased DT, T(+), and T(-), and these effects were attenuated by angiotensin II, L-arginine, and 8-bromo-cGMP. The effects of angiotensin II and L-arginine were blocked by inhibition of nitric oxide release with N(omega)-nitro-L-arginine. Neither the bradykinin B2 antagonist nor the cyclooxygenase inhibitor altered the effects of angiotensin II. We concluded that angiotensin II partially inhibits the contractile response of cardiac papillary muscles to isoproterenol This effect is likely mediated by nitric oxide release, perhaps acting via cGMP. Kinins and prostaglandins do not appear to participate in the inhibitory effect of angiotensin II. Attenuation of the contractile effect of isoproterenol by angiotensin II may help explain why cardiac function improves in heart failure after blockade of the renin-angiotensin system.
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PMID:Myocardial contractility is modulated by angiotensin II via nitric oxide. 861 28

Heart failure is a physiopathological condition, with an increasing incidence and prevalence, involving the action of a series of mechanisms known as 'compensators', which are phylogenetically ready to normalize minute volume and blood pressure. These mechanisms include the activation of a series of neurohormonal systems: the sympathetic nervous system, the aldosterone renin-angiotensin system, vasopressin arginine, endothelin, which are basically vasoconstrictors, with the counterpoint of other vasodilator systems, such as the endothelial relaxation factor, certain prostaglandins and the bradykinin-kallikrein system, which modulate global response. The authors review the physiopathology of each of these systems, as well as their significance in the diagnosis and prognostic evaluation of heart failure. We analyze the possible deleterious effects of neurohormonal activation, anatomically and at the cardiovascular function level, and try to determine if they are capable of explaining the evolution and progression of heart failure, in a truly vicious circle, up until the irreversible heart failure phase. We review the current importance of the inhibition of the aldosterone renin-angiotensin system in the prophylaxis and treatment of heart failure. Furthermore, we describe the present-day value of the inhibition of the sympathetic nervous system in some forms of heart failure. We also analyze the different pharmacological treatment for heart failure: diuretics, inotropic agents, vasodilators (in their different pharmacological types), paying particular attention to their action on neurohormonal systems and their implications in the prognosis and evolution of heart failure.
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PMID:[Neurohormonal factors in heart failure. I]. 865 Mar 99

1. The role of nitric oxide (NO) in congestive heart failure was investigated by studying the acute haemodynamic, hormonal and renal effects of N(G)-monomethyl-L-arginine (L-NMMA(, a nitric oxide inhibitor, given as incremental bolus doses in six sheep before (normal) and after induction of heart failure (HF) by rapid left ventricular pacing (LVoff+). 2. 6-NMMA caused significant initial dose-dependent rises in left ventricular systolic pressure, mean arterial pressure (MAP), peripheral resistance (PR) and left atrial pressure and declines in cardiac output in both normal and HF states (maximum response in 2-6 min). These responses were all but abolished when L-arginine was given concurrently with L-NMMA. The dose-response curve for the L-NMMA-induced rise in MAP was shifted to the right following LVP (P < 0.05), which is consistent with previous observations of blunted NO synthase activity in HF. A subsequent decline in MAP and PR to below prebolus levels was observed 30-60 min after L-NMMA administration in the paced state. No significant hormonal or renal effects were observed. 3. In conclusion, the present study confirms the important haemodynamic role played by endogenous NO in the normal state and demonstrates a blunted pressor response to NO inhibition in this model of heart failure.
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PMID:Nitric oxide inhibition in an ovine model of heart failure. 871 79

Heart failure is a physiopathological condition, with an increasing incidence and prevalence, involving the action of a series of mechanisms known as "compensators", which are phylogenetically ready to normalize minute volume and blood pressure. These mechanisms include the activation of a series of neurohormonal systems: the sympathetic nervous system, the aldosterone renin-angiotensin system, vasopressin arginine, endothelin, which are basically vasoconstrictors, with the counterpoint of other vasodilator systems, such as the endothelial relaxation factor, certain prostaglandins and the bradykinin-kallikrein system, which modulate global response. The authors review the physiopathology of each of these systems, as well as their significance in the diagnosis and prognostic evaluation of heart failure. We analyze the possible deleterious effects of neurohormonal activation, anatomically and at the cardiovascular function level, and try to determine if they are capable of explaining the evolution and progression of heart failure, in a truly vicious circle, up until the irreversible heart failure phase. We review the current importance of the inhibition of the aldosterone renin-angiotensin system in the prophylaxis and treatment of heart failure. Furthermore, we describe the present-day value of the inhibition of the sympathetic nervous system in some forms of heart failure. We also analyze the different pharmacological treatments for heart failure: diuretics, inotropic agents, vasodilators (in their different pharmacological types), paying particular attention to their action on neurohormonal systems and their implications in the prognosis and evolution of heart failure.
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PMID:[Neurohormonal factors in heart failure. II]. 874 85

Heart failure is a physiopathological condition, with an increasing incidence and prevalence, involving the action of a series of mechanisms known as "compensators", which are phylogenetically ready to normalize minute volume and blood pressure. These mechanisms include the activation of a series of neurohormonal systems: the sympathetic nervous system, the aldosterone renin-angiotensin system, vasopressin arginine, endothelin, which are basically vasoconstrictors, with the counterpoint of other vasodilator systems, such as the endothelial relaxation factor, certain prostaglandins and the bradykinin-kallikrein system, which modulate global response. The authors review the physiopathology of each of these system, as well as their significance in the diagnosis and prognostic evaluation of heart failure. We analyze the possible deleterious effects of neurohormonal activation, anatomically and at cardiovascular function level, and try to determine if they are capable of explaining the evolution and progression of heart failure, in a truly vicious circle, up until the irreversible heart failure phase. We review the current importance of the inhibition of the aldosterone renin-angiotensin system in the prophylaxis and treatment of heart failure. Furthermore, we describe the present-day value of the inhibition of the sympathetic nervous system in some forms of heart failure. We also analyze the different pharmacological treatments for heart failure: diuretics, inotropic agents, vasodilators (in their different pharmacological types), paying particular attention to their action on neurohormonal systems and their implications in the prognosis and evolution of heart failure.
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PMID:[Neurohormonal factors in heart failure (and III)]. 875 6


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