[Metabolic effects of static physical load under the conditions of pharmakologicheskoĭ mobilization of physical endurance]

The model of static physical loading (SPL) was used to study the biochemical effects of graded static tension and potentiality for pharmacological mobilization of physical endurance with participation of male volunteers. A close pathogenetic linkage between the established metabolic effects of the model and their adaptive adequacy to the stressing factor show that there is every reason to arrange the observed shifts in a SPL syndrome. The SPL syndrome is primarily manifested by exaggerated tone of the adrenoactive structures, inhibition of insulin production by the pancreas, activation of the neuropeptide anti-stress mechanisms, predominant utilization of the lipid substrate in energy production, intensification of protein catabolism, and increase in myocyte membrane permeability due to energy deficit. The investigation demonstrated that improvement of static physical endurance can be attained with a mobilizing stimulator (sidnocarb) and a combination of sidnocarb with a nonmediatory preparation (bemytil). This pharmacological combination levels side-effects of exorbitant activation of the adrenal system. On the contrary, a metabolic vitamin-microelements complex ("cocktail C") perceivably enhances SPL endurance (sidnocarb dose was lowered in three times), possesses the stress-protective effect, the ability to moderate the intensity of free (uninvolved in phosphorylation) oxidation and to optimize energy-plastic processes with predominant utilization of the lipid substrate.

[Role of endothelin and nitric oxide in early gut ischemia]

OBJECTIVE

Inadequate perfusion in splanchnic organs and especially in the gut during acute burn period has been reported in many conventionally "successfully" resuscitated patients, but the mechanisms still remain unclear and its early preventive measures need to be further studied. The aim of this study is to evaluate the role of endothelin and nitric oxide in gut ischemia.

METHODS

Eighteen male pigs were randomly assigned to one of the three groups: group C, a sham burn group that was subjected to all surgical procedures except burn; group B, sustained 30% TBSA cutaneous thermal burn; Group N, NO donor (C87-3754) was given intravenously (0.0125 mg.kg-1.min-1) at the beginning of resuscitation.

RESULTS

In group B, PVF decreased rapidly after burn, and did not recover in the observation period (72 h), ET levels in portal blood and intestinal tissue elevated contrary to the changes in NO. In group N, PVF was higher than in group B.

CONCLUSION

1. Changes in ET and NO may influence the protal blood flow. 2. NO donor was proved to be beneficial in improving GI tissue perfusion by releasing NO.

The role of nitric oxide in modulating ischaemia-induced arrhythmias in rats

The effect of a nitric oxide (NO) donor and the influence of endogenous NO in modulating ischaemia-induced arrhythmias was assessed in anaesthetised rats. The nitric oxide donor C87-3754 (1 mg/kg) caused a significant reduction in arterial blood pressure before coronary artery ligation but did not influence the incidence or severity of ventricular arrhythmias during a 30-min period of myocardial ischaemia [60 and 58% incidence of ventricular fibrillation (VF) in control and treated rats, respectively]. When the hearts were preconditioned by a short (3 min) coronary artery occlusion before the 30-min period of ischaemia, there was a marked reduction in both the number of ventricular ectopic beats (260 +/- 65 vs. 812 +/- 256 beats/min in controls; p < 0.05) and the incidence of ventricular fibrillation (9 vs. 67% in controls; p < 0.05). Neither NG-nitro-L-arginine methyl ester (L-NAME; 10-100 mg/kg) nor methylene blue (1-50 mg/kg) attenuated this marked antiarrhythmic effect of preconditioning. L-NAME caused a significant increase in blood pressure with all doses used, whereas methylene blue did not increase blood pressure. Both L-NAME and methylene blue attenuated ventricular arrhythmias in non-preconditioned hearts. L-NAME reduced the number of ventricular ectopic beats (from 812 +/- 256 to 318 +/- 81 beats/min at 10 mg/kg; p < 0.05), whereas methylene blue decreased the incidence of VF from 67 to 20% at a dose of 50 mg/kg (p < 0.05). These findings suggest that neither endogenous nor exogenously administered NO reduces ischaemic arrhythmias in anaesthetised rats. Furthermore, the antiarrhythmic effect of preconditioning in this species appears to be independent of NO. The antiarrhythmic effects seen with both methylene blue and L-NAME may be the result of actions other than inhibition of the production or actions of NO.

Effects of S-ethylisothiourea, a potent inhibitor of nitric oxide synthase, alone or in combination with a nitric oxide donor in splanchnic artery occlusion shock

1. The aim of this study was to compare the effects of an intravenous infusion of a potent and non selective nitric oxide synthase inhibitor S-ethylisothiourea (Ethyl-TU) with that of a nitric oxide (NO) donor on the pathological sequelae associated with splanchnic artery occlusion (SAO) shock. In addition the effects of the combination of these two treatments were also investigated. 2. SAO shock was induced in anaesthetized rats by clamping splanchnic arteries for 45 min. Sham operated animals were used as controls. Survival time, white blood cell (WBC) count, mean arterial blood pressure, myeloperoxidase activity (MPO; studied as a quantitative means to evaluate neutrophil accumulation) and the responsiveness of aortic rings to acetylcholine (ACh, 10 nM-10 microM) and to phenylephrine (PE, 1 nM-10 microM) were studied. 3. SAO shocked rats had a decreased survival rate (0% survival 2 h after the release of occlusion) and survival time (76 +/- 10 min), increased MPO activity in the ileum (3.39 +/- 0.8 u x 10(-3) g-1 tissue), a marked leukopenia and a profound hypotension. In addition aortic rings from shocked rats showed a marked hyporeactivity to PE and reduced responsiveness to ACh. Endothelium denuded aortic rings had also a marked hyporeactivity to PE. 4. In vivo administration of Ethyl-TU (0.1 mg kg-1 h-1, beginning 1 min after the onset of reperfusion) significantly increased survival time and rate, improved mean arterial blood pressure, restored the responsiveness to PE, but did not change MPO activity, leukopenia or the impairment in the responsiveness of aortic rings to ACh. Addition of Ethyl-TU (2 microM) to endothelium denuded aortic rings in vitro, restored the marked hyporeactivity to PE. Administration of the NO donor C87-3754 (0.75 mg kg-1 h-1, beginning 1 min after the onset of reperfusion) slightly increased survival time and reduced MPO activity and leukopenia, but did not change survival rate and mean arterial blood pressure. In addition C87-3754 restored the responsiveness of aortic rings to ACh to control values, but did not modify the hyporeactivity to PE. The combination of these two interventions produced a higher degree of protection than either Ethyl-TU or C87-3754 alone. In fact, co-administration of Ethyl-TU plus C87-3754 completely prevented mortality, reduced MPO activity, attenuated leukopenia and the profound hypotension and restored the impaired responsiveness of aortic rings to PE and ACh. 5. Our study suggests that treatment with a nitric oxide synthase inhibitor combined with an NO donor may be a new therapeutic approach to the treatment of splanchnic artery occlusion shock.

Short-term hemodynamic, anti-ischemic, and antianginal effects of pirsidomine, a new sydnonimine

Pirsidomine is a new sydnonimine compound in clinical development. As a prodrug, it is transformed into a nitric oxide-releasing metabolite in vivo. In animal tests there were no signs of tolerance with repeated administration. The short-term effects of 10, 20, and 40 mg of the drug on pulmonary hemodynamics and ischemic parameters were examined at rest and during exercise in a double-blind, randomized, placebo-controlled study. The study included 48 patients with documented coronary artery disease and exercise-induced ST-segment depression. Compared with the baseline test, there was a reduction of diastolic pulmonary artery pressure with pirsidomine at rest (placebo: -0.4 +/- 0.5 mm Hg; 10 mg: - 1.5 +/- 2.4 mm Hg; 20 mg: - 1.4 +/- 1.1 mm Hg; 40 mg: - 2.3 +/- 1.3 mm Hg [p < 0.05 ]) and at the highest comparable workload (placebo: -2.8 +/- 1.9 mm Hg; 10 mg: -7.3 +/- 6.8 mm Hg; 20 mg: -8.4 +/- 7.9 mm Hg [p <0.05]; 40 mg: -13.8 +/- 7.1 mm Hg [p <0.05]). ST-segment depression decreased at the highest comparable workload (placebo: -0.33 +/- 0.49 mm; 10 mg: -1.33 +/- 1.37 mm [p <0.05]; 20 mg: -1.33 +/- 0.83 mm [p <0.05]; 40 mg: -1.96 +/- 0.86 mm [p <0.05]) and total exercise time increased (placebo: 15 +/- 48 s; 10 mg: 98 +/- 126 s; 20 mg: 165 +/- 251 s [p <0.05]; 40 mg: 155 +/- 174 s [p <0.05]). Of 40 patients who complained of angina pectoris symptoms in the baseline test, 15 became free of angina pectoris with pirsidomine. Compared with placebo, blood pressure, heart rate during exercise, and cardiac output during exercise showed no significant change. Plasma concentration response relations of the metabolite revealed concentrations that caused a half-maximum effect of 6 ng/ml, 13 ng/ml, 20 ng/ml, and 28 ng/ml in reduction of ST-segment depression, reduction of diastolic pulmonary artery pressure, relief of angina pectoris symptoms, and an increase in exercise duration, respectively. Thus, pirsidomine is an effective anti-ischemic and antianginal agent. A significant preload reduction was obtained with plasma metabolite concentrations lower than those necessary to achieve a satisfactory antianginal effect.

Antiischemic effects of pirsidomine, a new nitric oxide donor

The antiischemic effect of pirsidomine (CAS 936 (3-(cis-2,6-dimethylpiperidino)-N-(4-methoxybenzoyl))-sydnon imine), a new nitric oxide donor, was investigated in a model of myocardial infarction in the dog. Dogs were anaesthetised, thoracotomized, and the left descending coronary artery was occluded for 6 h. Pirsidomine was given intraduodenally (i.d.) at the dose of 1.0 mg/kg to 11 dogs 30 min prior to coronary occlusion. Eleven dogs received the solvent i.d. and served as controls. Pirsidomine administration completely prevented the increase in left ventricular end-diastolic pressure and pulmonary artery pressure induced by the coronary occlusion and resulted in a marked decrease in systolic and diastolic blood pressure, cardiac output, left ventricular contractility, left ventricular work and left ventricular oxygen consumption. Additionally, pirsidomine completely prevented the occlusion-induced increase in flow in the non-occluded circumflex coronary artery. Regional blood flow measurements (with radioactive microspheres) revealed that pirsidomine induced a significant reduction in blood flow in the non-ischemic areas (both epi- and endocardial) but in the course of the ischemia, significantly increased flow in the ischemic epicardial areas. Infarct-size (triphenyltetrazolium chloride technique) in control dogs was 45% of the area at risk, but only 26% (P < 0.05) in pirsidomine-treated dogs. Thus, pirsidomine had a marked antiischemic effect in this model. This was probably due to the hemodynamic unloading of the heart as well as to redistribution of blood from the non-ischemic to the ischemic areas of the myocardium.

[The effect of fenazepam and sidnocarb in the phantom pain syndrome]

The phantom-pain syndrome model was used to examine the effects of phenazepam, sydnocarb and their combination in chronic oral administration. Phenazepam was shown to have no effects on the development of the phantom-pain syndrome. Sydnocarb arrested the progression of the pain syndrome, reduced its symptoms, alleviated inflammatory manifestations and extremity edema. The agent increased animals' excitability. When their combination was used, the clinical signs of the pain syndrome developed in the same way as with sydnocarb alone. At the same time phenazepam decreased the animals' aggression and excitability caused by sydnocarb. It is suggested that enhancing the efficiency of inhibitory GABAergic processes may result in lower clinical signs of the phantom-pain syndrome in case of involvement of brain catecholaminergic systems whose activation increases the inhibitory functions of its related GABA. The sympathomimetic action of sydnocarb induces an elevation of norepinephrine concentrations in the nerve endings and postsynaptic receptors, resulting in trophic improvement and restoration of tissue viability.

[Anti-ulcer effect of the drug OF-743 in an acid model of ulcer formation by the Okabe method]

The application of acetic acid (100%) on gastric serosa produces hemorrhagic lesions, erosions and ulcers in the gastric mucosa of rats. Intraperitoneal injections of OF-743, a derivative of sydnonimine during 3 days after the acid application have revealed lesser expressed mucosal lesions: only hemorrhagic lesions and rather small erosions. The lesions degree in rats subjected to the action of OF-743 was 2.7 as compared with 4.4 in control rats without OF-743. Our findings indicate that OF-743 shows not only protective antiulcer action, as it was discovered earlier, but has also curative antiulcer effect.

Some new aryl-sydnones: effects on murine tumours

The effects of new aryl-sydnones: 3-[4-X-3-nitrophenyl]-1,2,3-oxadiazolium-5-olates, where X = Cl (SYD-1); pyrrolidino (SYD-2); piperidino (SYD-3) and morpholino (SYD-4) on the survival of mice bearing Sarcoma 180, Ehrlich carcinoma, B10MCII (Fibrous histiocytoma) and L1210 leukemia ascitic tumours, on the proliferation of cultured tumour cells and on the synthesis of DNA in L1210 leukemia were determined. SYD-1 and SYD-2 in vivo significantly enhanced the survival of S180, Ehrilich and B10MCII tumour-bearing mice. Furthermore, SYD-2 showed significant activity against L1210. SYD-3 and SYD-4 did not show antitumour activity. SYD-1, in vitro was the most cytotoxic against all the above tumour cells. All of the drugs tested inhibited thymidine uptake by L1210 cells, SYD-4 being the least active.

Cardioprotection and attenuation of endothelial dysfunction by organic nitric oxide donors in myocardial ischemia-reperfusion

The effects of two nitric oxide (NO) donors were evaluated in a 6-h model of feline myocardial ischemia-reperfusion. After 80 min of a 90-min ischemic period, SIN-1 or C87-3754 or their respective controls (i.e., 0.9% NaCl or C88-3934, a control compound which does not release NO) were given i.v. as a bolus (0.1 mg/kg) and infused at 1 mg/kg/h for the entire 4.5-h reperfusion period. Administration of the active NO donors significantly decreased the necrotic area/area-at-risk ratio from 29 +/- 3% in the vehicle group to 9 +/- 2 and 11 +/- 5% in the SIN-1 and C87-3754 groups, respectively (P less than .001). The inactive NO donor C88-3934 failed to reduce infarct size (31 +/- 3%). Neither NO donor reduced the accumulation of neutrophils in the necrotic area when compared to their respective control groups, but both agents significantly attenuated coronary endothelial dysfunction as shown by a vasorelaxation to acetylcholine of 62 +/- 2 and 64 +/- 3% in the SIN-1- and C87-3754-treated arteries, as compared to only a 27 +/- 3 and 34 +/- 4% vasorelaxation in the vehicle and inactive NO donor groups, respectively (P less than .001). Our studies show that SIN-1 and C87-3754 exert beneficial effects in a 6-h model of myocardial ischemia-reperfusion. Both NO donors decreased myocardial necrosis and decreased the reperfusion-induced endothelial dysfunction without significantly altering the pressure-rate index (i.e., an index of myocardial oxygen demand).

[Antiulcerogenic (therapeutic and preventive) properties of a phenylalkyl syndonimine psychostimulant]

Intragastric administration of 96% ethanol, 1 ml/100 g of body mass, induced ulcerous impairments of rat gastric mucosal membrane, which were marked within 8 min after ethanol administration and reached the maximal size within 3 hrs. Psychostimulants of the phenylalkyl sydnonimime series OF 743, administered after the ethanol treatment, decreased distinctly the ethanol-induced impairments of gastric mucosal membrane and this effect was higher in simultaneous inoculation of the drug and ethanol. The data obtained suggest that preparation OF 743 exhibited both protective and curative antiulcerogenic efficiency.

[Functional changes of the cardiovascular system and their pharmacological correction during suited immersion]

In the course of 126 man/exposures of 3 hours to 3 days in duration, in which 39 test subjects took part, circulation responses to the upright and supine body position during suited immersion as well as orthostatic and exercise tolerance after immersion were investigated. During 24 man/exposures for 2 days the subjects were administered per os placebo or one of the four neurotrophic drugs: sydnocarb, sydnogluton, sydstrigluton, estrigluton. Clinical observations, instrumented data and methodical features of the immersion model used give evidence that the suited immersion has advantages over currently used procedures simulating the effects of hypogravity. The drugs allowed cardiovascular correction that increased aerobic capacity of the body and enhanced cardiovascular orthostatic and exercise tolerance.

[The immunization of white rats with a covalent conjugate of sidnofen and serum albumin suppresses chronic ethanol consumption]

The influence of white rats of alcohol abuse formation of immunization by covalent conjugates of serum albumin with psychostimulant sydnophen was investigated. Immunization by conjugates where the molar sydnophen: protein ratio was 18:1-33: 1 results in significant depression of 15% ethanol consumption (in the condition of free choice between water and ethanol solution).

[Pharmacologic correction of the effect of cold on man]

The effect of pharmacological stimulants and prescriptions on the thermal status of man and their possible use to extend the exposure to the cold environment were investigated. The effectiveness of the following drugs and prescriptions was assessed: sydnocarb, phenamine, indopan; glutamic acid + lagochilus + ephedrine; sydnocarb + glutamic acid (sydnogluton); ephedrine + glutamic acid + strychnine. The test subjects were kept in air (in a thermal chamber) at -20 degrees C or in water at 0 to 2.5 degrees C (resting or swimming). The most effective treatment was provided by sydnocarb (effective doses were 10 mg X 2 or 30 mg X 5 in air or water, respectively) and sydnogluton (sydnocarb 30 mg + glutamic acid 0.25 g X 5 in cold water). When compared to placebo, sydnocarb (or sydnogluton) assured better thermal parameters of the body in cold water and longer (by 2-6 hrs) exposure which increased to 20 hrs.

Molsidomine prevents post-ischaemic ventricular fibrillation in dogs

Forty anaesthetized dogs were subjected to left circumflex coronary artery ligation followed by reperfusion. Molsidomine was randomly administered to 20 dogs (50 micrograms kg-1 as an i.v. bolus - 15 min prior to coronary occlusion - followed by an infusion of 0.05 micrograms kg-1 min-1. Standard electrocardiographic leads 2 and 3 were continuously recorded to measure ST segment and delta R% changes and to document both the number of ventricular premature beats and the onset of ventricular fibrillation; aortic pressure and cardiac output were measured; thromboxane B2 plasma levels, platelet aggregation produced by ADP, and molsidomine plasma levels were determined before and at 10, 30 and 75 min after the start of the drug protocol. Molsidomine protected the treated animals from early (10 min) post-ischaemic ventricular fibrillation (0 of 20 vs 6 of 20, P = 0.0202), reduced the incidence of overall post-occlusion ventricular fibrillation (3 of 20 vs 10 of 20, P = 0.0407) and improved the total survival rate (P = 0.0067). In molsidomine treated dogs: mean aortic pressure and the rate-pressure product were lowered 10 min after the start of the drug; immediate post-occlusion (3 min) ST segment changes (0.82 +/- 0.52 vs 1.52 +/- 0.78 mV, P less than 0.025) and delta R% changes (37 +/- 50 vs 90 +/- 84%, P less than 0.025) were less marked; the number of ventricular premature beats was lowered and finally, a progressive decline of platelet aggregation produced by ADP was achieved after 75 min of drug infusion. These results were obtained in the presence of mean plasma levels of molsidomine ranging from 20 to 28 ng ml-1. The time-action curve of the antifibrillatory effect of molsidomine parallels those at the level of post-ischaemic electrocardiographic changes.

Combined digoxin-molsidomine therapy in congestive heart failure following acute myocardial infarction

The acute hemodynamic effects of combining administration of digoxin (DIG)(0.01 mg/kg intravenously) with molsidomine (MLS)(4 mg sublingually) were compared with those of DIG and MLS considered alone in 12 patients with congestive heart failure following acute myocardial infarction. The patients were classified into two subgroups, A (cardiac index [CI] less than or equal to 2.2 L/min/m2 and B (CI greater than 2.2 L/min/m2), to verify differences between the responses to the three drug regimens. MLS significantly reduced systolic blood pressure from 121.2 +/- 12.3 (mean +/- SD) to 111.7 +/- 10.9 mm Hg (p less than 0.01) after 60 min, mean right atrial pressure (RAP) from 6.2 +/- 3.6 to 2.4 +/- 2.1 mm Hg (p less than 0.0001), mean pulmonary arterial pressure (PAP), left ventricular filling pressure (LVFP) from 20.6 +/- 2.1 to 12.2 +/- 2.8 mm Hg (p less than 0.0001), and pulmonary vascular resistance (PVR). Left ventricular stroke work index (LVSWI) significantly increased after 60 min. DIG induced a significant reduction in heart rate, RAP, PAP, and LVFP from 20.1 +/- 2 to 14.3 +/- 2.7 mm Hg (p less than 0.0001) after 90 min. Stroke volume index (SVI) increased from 24.7 +/- 4.2 to 27.7 +/- 3.1 ml/beat/m2 (p less than 0.001) and LVSWI from 25.9 +/- 7.2 to 31.9 +/- 5.4 g X m/m2 (p less than 0.0001). The combination of DIG and MLS produced a reduction in RAP, PAP, and LVFP greater than that achieved with either agent alone, with a further shift of the ventricular function curve to the left, thereby leading to an improvement in cardiac performance.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of the acute administration of molsidomine in refractory congestive heart failure. A double-blind randomized non-invasive study]

The effect of vasodilator Molsidomine (M) vs placebo on left ventricular dimensions and function measured by echocardiography was evaluated in a randomized study on 23 patients (pts) with refractory congestive heart failure (R CF) (NYHA class III-IV). The pts were randomized in two groups: group A (12 pts) received M, group B received an identical appearing placebo. Adequate echocardiograms were obtained before and one hour after 2 tablets of M (4 mg) or P; left ventricular end-diastolic and end-systolic diameters (LVEDD and LVESD), mean rate of circumferential shortening and left ventricular fractional shortening were calculated on the echocardiograms obtained. At the same time mean arterial pressure (MAP) and heart rate were measured. In group A, the single-dose test induced a significant reduction in LVEDD (74.1 +/- 7.2 to 72.1 +/- 7.1 mm; p less than 0.01), in LVESD (64.4 +/- 8.4 to 61.6 +/- 7.4 mm; p less than 0.01) and in MAP (96.5 +/- 8.3 to 85.4 +/- 7.2 mmHg; p less than 0.05). No significant changes were noted in the other parameters. Moreover, changes of parameters evaluated in group A between pts with idiopathic cardiomyopathy and pts with ischemic heart disease showed no statistical differences. Thus, acute Molsidomine therapy is effective in reducing left ventricular diameters and MAP in pts with RCF without changes of echocardiographic contractility indexes.

[Hemodynamic effects of molsidomine in patients with cardiac insufficiency at high altitudes]

Central hemodynamic effects of 0.05 mg/kg molsidomine were examined in 60 patients with decompensated mitral disease dwelling at low and medium altitudes. M-echocardiography was used to assess hemodynamic shifts. The assessments were made during the diagnostic probing of a pulmonary artery in 23 cases. Hemodynamic efficacy of molsidomine was more pronounced up in the mountains. Rationale are given for expanding indications for peripheral vasodilators (molsidomine) in highlanders with congestive heart failure.

Haemodynamic effects of molsidomine in patients with severe chronic coronary disease

The haemodynamic effects of a single dose of intravenous molsidomine were assessed in 12 patients with severe coronary disease. The investigation was carried out at rest during angina induced by pacing and after molsidomine during pacing at the rate at which angina had been produced. During angina, left ventricular systolic and end-diastolic pressure rose, left ventricular stroke work fell and coronary flow and myocardial oxygen consumption increased by 58.3% above the control levels. After the administration of molsidomine, atrial stimulation was not followed by angina and there were no significant changes in systolic blood pressure. Left ventricular end-diastolic pressure fell sharply and coronary flow and myocardial oxygen consumption were only 38% and 33% higher, respectively, than the control levels. The beneficial effects of molsidomine in ischaemic heart disease, therefore, are the result of peripheral vasodilation which, by reducing the preload and afterload, lowers the oxygen requirements of the myocardium and thus increase the threshold for angina. A direct action on the coronary network can not be excluded but if such an action does exist it must be very small in the light of the marked systemic effect.

[Various aspects of drug therapy of chronic forms of ischemic heart disease]

Experience in the treatment of over 500 chronic coronary patients with various anti-anginal drugs or their combinations is summarized. Controlled (double blind) and open studies and acute pharmacologic tests demonstrated comparative efficacy of depot-nitrates, beta-blockers, oxyfedrine, cordaron, lidoflazinum, molsidamine (corvaton). The effects on exercise tolerance (bicycle ergometry) with isolated and combined use of the drugs are described. Indications for surgery are discussed.

[Relation between therapeutic efficacy of antianginal preparations in patients with ischemic heart disease and their effect on the rheologic properties of blood]

The effects of a variety of currently-used anti-anginal drugs on major hemorheologic parameters (blood viscosity in the 0.692-2348 s-1 variation rates range, plasma viscosity, erythrocyte and platelet function) and also the hemostatic system were examined in 100 chronic coronary patients during specific treatment courses. The nitrates, beta-blockers (alone or in combinations), cordaron and molsidomin were shown to produce positive effects on blood rheology. A relationship was demonstrated between physical stress tolerance and blood viscosity pattern in propranolol-treated coronary patients. It is suggested that positive hemorheologic effects of anti-anginal drugs may be an important constituent of their therapeutic action and, as such, provide an additional marker of their efficiency in coronary heart disease.

[Intravenous administration of molsidomin in the acute period of myocardial infarct]

A study of central hemodynamic parameters, ECG charting and the activity of serum CPK and its MB fraction in 58 patients with acute myocardial infarction demonstrated that intravenous administration of 20 mg Corvaton, at the rate of 3 micrograms/kg/min, was effective for both controlling an acute left-ventricular failure, and limiting the infarcted area. A three-day treatment normalized systemic and central hemodynamic parameters in cases of medium-size infarction, and considerably reduced manifestations of acute left-ventricular failure in patients with a large area of necrosis.

Effectiveness of molsidomine in the long-term treatment of exertional angina pectoris and chronic congestive heart failure

Molsidomine, similar to nitrates, improves myocardial blood flow in hypoperfused, poststenotic myocardial regions, reduces left ventricular pressure and volumes, and leads to improvement in impaired regional wall motion. In patients with chronic, stable anginal pectoris who underwent long-term treatment with 2 mg of molsidomine three times daily there were reductions in ST segment depression of 45% and 9% at 1 and 3 hours after administration, respectively, and slight but statistically significant reductions in the rates of anginal attacks and nitrate consumption of 16% and 18%. Administration of 3 mg three times daily did not render more significant effects. Doubling the frequency of administration--that is, 2 mg six times daily--led to reductions in the rates of anginal attacks and nitrate consumption of 38% and 36%, respectively, and 4 mg led to a more marked reduction in ST segment depression of 57%. With administration of 8 mg of sustained-release molsidomine, a prolonged antiischemic effect was documented with reductions in ST segment depression of 74% at 1 hour and 31% at 8 hours after medication. In patients with congestive heart failure, 1 hour after administration of 4 mg of molsidomine there were significant reductions in systolic and diastolic pulmonary artery pressures of 25% and 30%, respectively. After 7 days of continuous treatment with 4 mg of molsidomine four times daily, comparable reductions in pulmonary artery pressure were observed. Thus molsidomine, in adequate dosages, elicits an unequivocal anti-ischemic and antianginal effect as well as a salutary reduction in left ventricular filling pressure.

Hemodynamic effects of molsidomine in patients with acute myocardial infarction

The hemodynamic effects of molsidomine were studied in 48 patients with acute myocardial infarction and compared with hemodynamic properties in a control group of 24 patients. The most pronounced decrease in pulmonary artery diastolic pressure occurs between 30 and 60 minutes after oral administration of 8 to 12 mg (n = 16). There is no major difference in action between the oral and intravenous application of 8 to 12 mg (n = 22). Its effect lasts about 3 to 4 hours and may exceed up to 8 hours in patients with left heart failure (n = 10). The mean arterial pressure is affected only with high doses (12 mg). Cardiac output decreases slightly only in patients without left heart failure. An additional intraindividual comparison of nitroglycerin (1.6 mg sublingually) and molsidomine (12 mg intravenously) (n = 11) revealed no significant difference in hemodynamic effectiveness. Molsidomine, like nitroglycerin, acts primarily to reduce cardiac preload. An additional moderate action on afterload with a slight decline in arterial pressure may be noticed at high doses.

Exercise tolerance in coronary patients: randomized trial of two-week treatment with molsidomine versus placebo

Using a randomized, double-blind, crossover protocol, we compared the effects of oral molsidomine (Corvaton, 6 mg/day) and placebo, administered alternately for two 14-day periods, on the exercise tolerance of 25 outpatients with coronary heart disease. Resting heart rate and oxygen consumption increased by 6.8% (p less than 0.005) and 12.6% (p less than 0.01), while peripheral systolic blood pressure was reduced by 5.1% (p less than 0.05). At submaximal workloads, systolic and diastolic blood pressures were reduced by 5.6% (p less than 0.001) and 6.1% (p less than 0.001), the pressure-rate product was reduced by 8.5% (p less than 0.05), and ST segment depression was reduced by 40.0% (p less than 0.005). At maximal exercise level, mechanical power increased by 32.4% (p less than 0.001) and oxygen consumption by 15.5% (p less than 0.005), while ST segment depression was reduced by 30.6% (p less than 0.001). No alteration was found in postexercise lung function tests. It is concluded that molsidomine reduces myocardial ischemia at both submaximal and maximal work levels and increases exercise tolerance significantly. These effects could be related to reduced myocardial oxygen requirements, reflected in a lower pressure-rate product at submaximal exercise and perhaps enhanced by a lower preload, which, moreover, would favor coronary flow in subendocardial layers. The drug has no adverse bronchopulmonary effects.

Clinical and hemodynamic effects of the new dilator drug molsidomine

The effects of a single 2 mg oral dose of molsidomine were assessed with treadmill multistage exercise testing in six men with stable angina. A double-blind, placebo-controlled protocol was used, with exercise to the point when anginal pain forced the patient to stop. Exercise was undertaken before and at 1/2, 1 1/2, 4, and 6 hours after drug administration. Molsidomine improved exercise performance, with the best antianginal effect at 1 1/2 hours after administration, when the mean times to limiting angina were approximately 6 3/4 minutes with placebo and 11 1/2 minutes with molsidomine (p less than 0.05). The corresponding energy expenditures were 33.8 and 77.6 mets, an increase of 130% with the active drug. Intra-arterial blood pressure recording verified that molsidomine had a vasodilator hemodynamic profile, and the immediate postexercise rate-pressure product 1 1/2 hours after molsidomine treatment was 232 mm Hg/min X 10(-2), compared with 183 mm Hg/min X 10(-2) after administration of placebo (NS). Side effects of molsidomine were limited to headache in two patients.

Effects of molsidomine on left ventricular dimensions and cardiac function in patients with chronic heart failure

The effects of molsidomine were studied in seven patients with refractory congestive heart failure by means of two-dimensional echocardiography. Four milligrams of molsidomine or placebo was sublingually administered in a double-blind crossover manner. End-diastolic dimension, end-systolic dimension, and mean velocity of circumferential fiber shortening were measured just below the mitral valve before drug or placebo administration and 1 hour later. No significant changes were observed with placebo. Heart rate and mean arterial pressure were not significantly modified with Molsidomine (80 to 83 bpm and 100 to 97 mm Hg, respectively). The reduction in end-diastolic dimension (67 to 61 mm; 9%; P less than 0.01) was slightly greater than the decline in end-systolic dimension (59 to 54 mm; 8%; p less than 0.01). The mean velocity of circumferential fiber shortening increased from 0.4 to 0.5 sec-1 but did not achieve statistical significance. Thus sublingual administration of molsidomine in patients with chronic heart failure reduces end-diastolic more than end-systolic dimension without effect on blood pressure, suggesting a predominant action on cardiac preload.

Active and passive changes in coronary diameter after vasodilation with SIN-1, the active metabolite of molsidomine

The vasodilating effects of intracoronary injections of 0.4 mg of SIN-1, the active metabolite of molsidomine, on epicardial coronary arteries and coronary stenoses were evaluated in 14 patients with coronary artery disease in a double-blind, randomized fashion vs placebo. Nine additional patients with well defined coronary stenoses received 0.4 mg of SIN-1 as well. Diameter changes of nonstenotic coronary arteries in proximal, medial, and distal coronary segments as well as changes of the residual luminal diameters within coronary stenoses were determined before (K), immediately after (M1), and 10 minutes after (M2) intracoronary administration of SIN-1. Aortic pressures and heart rate were monitored continuously. After administration of SIN-1, the diameters of nonstenotic coronary arteries increased in proximal segments by 9.4% (M1) and 11.7% (M2), in medial segments by 17.9% (M1) and 17.6% (M2), and in distal segments by 25.6% (M1) and 28.8% (M2). Within coronary stenoses the residual luminal diameters showed mean increases of 31.5% (M1) and 48.3% (M2). Placebo administration did not alter coronary diameters significantly. Aortic pressure and heart rate did not change after administration of SIN-1 or placebo. SIN-1 effectively dilates nonstenotic and stenotic coronary segments, as do nitrates and calcium channel blockers. By intracoronary injections, the direct effects on coronary vessels can be evaluated without interference with systemic effects. The increase in the residual luminal diameters within dynamic coronary stenoses after administration of SIN-1 is probably an important antianginal mechanism also for molsidomine.

Double-blind, randomized, placebo-controlled study of molsidomine in patients with stable effort angina receiving beta-blocker therapy with atenolol

A randomized, double-blind, placebo-controlled trial was performed in 12 patients with chronic and stable effort angina to study the antianginal and anti-ischemic actions of a single dose of molsidomine in addition to long-term therapy with a long-acting beta-adrenergic blocker (100 mg of atenolol daily). Efficacy was assessed by means of objective endpoints obtained by computer-assisted exercise testing. The mean exercise time to produce angina improved significantly from 330 +/- 38 seconds (mean +/- SEM) in patients after administration of atenolol and placebo to 420 +/- 36 seconds after administration of atenolol and molsidomine. Similar significant improvements were seen in ST segment changes at an identical exercise duration, in maximal heart rate, and in maximal exercise duration. The increased anginal threshold and the reduced ischemic changes were not explained by changes in the rate-pressure product at submaximal levels. Thus molsidomine showed antianginal and anti-ischemic efficacy in the treatment of stable effort angina additional to the effect of long-term therapy with beta-adrenergic blockers.

Hemodynamic and coronary effects of molsidomine at basal state, during atrial pacing, and during cold pressor test in patients with stable angina pectoris

Heart rate (HR), cardiac output (CO), coronary sinus blood flow (CSF), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), mean arterial (MAP), and coronary arteriovenous difference for oxygen (AVDcO2) were measured in patients with stable angina pectoris without cardiac failure before and 40 to 60 minutes after administration of 2 or 3 mg of molsidomine. In 20 patients these measurements were made in basal state during spontaneous rhythm. In eight of these patients (including three receiving beta blockers) the measurements were made during atrial pacing. In eight other patients, all receiving long-term beta-blocker therapy, the measurements were made during cold pressor test. At the basal state in spontaneous rhythm, a gradual reduction in the LVSP to 70% or less of its initial value was observed in four patients receiving 3 mg of molsidomine (two of whom received beta-blocker treatment). The LVSP was immediately restored by vascular filling. In the 16 other patients molsidomine decreased LVSP, LVEDP, MAP, CO, and double product (DP = LVSP X HR). The AVDcO2 was unchanged. CSF and myocardial oxygen uptake index (MVO2 = CSF X AVDcO2) were decreased. During atrial pacing, hemodynamic and coronary effects were similar to those seen in the basal state. During the cold pressor test, the increases in LVSP, MAP, and LVEDP were significantly reduced by molsidomine. The variations in CSF and coronary resistance (MAP/CSF) were also significantly different after administration of molsidomine, with better metabolic regulation of the coronary circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of molsidomine on hemodynamics and blood gases in acute myocardial infarction with left heart failure

We studied the effects of molsidomine on hemodynamic properties and blood gas levels in eight patients with acute myocardial infarction and left heart failure. One hour after an 8 mg intravenous bolus injection, pulmonary wedge pressure and right atrial pressure decreased, respectively, from 30 +/- 9 to 23 +/- 12 mm Hg (p less than 0.01) and from 10.4 +/- 3.6 to 7.8 +/- 4.0 mm Hg (p less than 0.05) without significant changes in heart rate, cardiac index, or systemic blood pressure. There was a mild decrease in arterial oxygen tension (from 61 +/- 15 to 56 +/- 6 mm Hg), but it was not significant. The drug induced no adverse effects. Intravenous bolus injection of molsidomine rapidly relieves pulmonary congestion in patients with acute myocardial infarction.

Long-term clinical and hemodynamic results of molsidomine treatment in patients with refractory heart failure

In this report we describe the clinical and hemodynamic response of refractory cardiac failure to molsidomine. In the first part of the study the hemodynamic effects of a single oral dose of 2 or 4 mg of molsidomine were compared with placebo control in 23 patients. In the second phase the dose 8 to 24 mg/24 hours was used in nine patients with functional class III or IV symptoms over an average period of 28 months (range 7 to 42 months); a hemodynamic control study was performed. These data demonstrate that molsidomine has a hemodynamic effect on pulmonary artery pressure for 5 to 6 hours, that the peak effect is reached between 1 and 1 1/2 hours after oral intake, and that the clinical and hemodynamic benefits of molsidomine may be maintained in the long term in patients with particularly severe cardiac failure. The conditions of seven patients were clinically improved with treatment; significant reductions in mean right atrial, pulmonary artery, and pulmonary capillary pressures were observed.

The influence of molsidomine on the hemodynamics of patients with chronic heart failure at rest and during exercise

The effect of molsidomine on hemodynamic properties was studied in 10 patients with chronic congestive heart failure in New York Heart Association functional classes III and IV. Ten patients with the same degree of heart failure served as control subjects. All patients were receiving standard therapy with digitalis and diuretics. Administration of a single dose of 4 mg of molsidomine orally in the initial phase resulted in significant decreases of pulmonary artery pressure, pulmonary capillary pressure, and right atrial pressure at rest and during exercise (p less than 0.01 and p less than 0.01, respectively). After long-term oral treatment with 4 mg of molsidomine three times daily over a period of 3 weeks, single dose administration of 4 mg of molsidomine orally again caused significant decreases of pulmonary artery, pulmonary capillary, and right atrial pressure at rest and during exercise (range p less than 0.01 to p less than 0.02). Cardiac output, heart rate, systemic arterial pressure, pulmonary artery resistance, and systemic arterial resistance were essentially unchanged.