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Query: UMLS:C0038454 (
stroke
)
147,016
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Experiments in monkeys have demonstrated that the chronic vasospasm and arterial injury reaction produced by subarachnoid blood injection can be prevented by treatment with the
phosphodiesterase
inhibitor phthalazinol. This protective effect, which is present even when the drug treatment is initiated after the subarachnoid blood injection, is presumed to occur because of the platelet inhibiting effect of phthalazinol.
Stroke
PMID:Prevention of experimental subarachnoid hemorrhage-induced intracranial arterial vasonecrosis with phosphodiesterase inhibitor phthalazinol (EG-626). 11 51
1. We have investigated the in vitro cardiac actions of flosequinan and of its major metabolite in man, BTS 53554. 2. Positive inotropic activity was seen with flosequinan in guinea-pig isolated ventricles, the threshold concentration for effect being less than 1 x 10(-5) M. BTS 53554 was approximately half as potent as the parent compound. 3. In guinea-pig working whole hearts flosequinan increased left ventricular dp/dtmax, indicating a positive inotropic action. This effect was accompanied by increases in heart rate, cardiac output and
stroke
volume. 4. The virtual complete inhibition of inotropic responses to flosequinan and BTS 53554 by carbachol suggests that these responses are adenosine 3':5'-cyclic monophosphate (cyclic AMP)-mediated. 5. Flosequinan was shown to increase calcium inward current in guinea-pig ventricle, an action consistent with a cyclic AMP involvement in the response. 6. The inotropic activity of flosequinan was not potentiated by the selective
phosphodiesterase
(
PDE
) III inhibitor SK&F 94120, a result which indicates that flosequinan does not increase cyclic AMP concentrations via stimulation of adenylate cyclase. 7. Flosequinan inotropic responses were potentiated by rolipram, a selective
PDE
IV inhibitor, a result consistent with flosequinan being itself a
PDE
III inhibitor. 8. Biochemical studies with purified enzymes confirmed that flosequinan and BTS 53554 are relatively selective inhibitors of
PDE
III. 9. A comparison of pharmacological and biochemical data for both flosequinan and BTS 53554 indicates that their
PDE
III inhibitory potency is sufficient to account for their inotropic activity.
...
PMID:Studies on the cardiac actions of flosequinan in vitro. 132 61
The effects of four inotropic agents with differing ancillary properties [a cardiac glycoside (digoxin), a combined alpha- and beta-adrenergic agonist (dobutamine), a beta-adrenergic agonist (prenalterol), and a
phosphodiesterase
inhibitor (amrinone)] alone and with subsequent addition of isosorbide dinitrate were compared in 48 consecutive acute myocardial infarction patients with radiographic and haemodynamic (pulmonary artery occluded pressure greater than 18 mm Hg) left ventricular failure. All agents with the exception of dobutamine reduced the elevated left heart filling pressure; only digoxin and dobutamine augmented the cardiac
stroke
volume index. All drugs except digoxin reduced the SVRI; an arteriolar constrictor response was evident 60 min after digoxin and a tachycardia resulted after combined alpha- and beta- and beta-adrenergic stimulations (dobutamine and prenalterol, respectively). The addition of isosorbide dinitrate reversed the inotrope-induced elevations of systemic arterial pressure and resulted in additional reductions in left heart filling pressure. These data suggest that, in the absence of substantial venodilator properties in an inotropic compound, reduction in elevated left heart filling pressure is not achieved with inotropic therapy alone in acute left ventricular failure and combining a venodilator may be haemodynamically advantageous.
...
PMID:Modulation of inotropic therapy by venodilation in acute heart failure: a randomised comparison of four inotropic agents, alone and combined with isosorbide dinitrate. 137 84
Selective inhibition of either the low Km cyclic AMP (cAMP) or low Km cyclic GMP (cGMP)
phosphodiesterase
(
PDE
) promotes vasorelaxation and, consequently, produces depressor effects. To evaluate the systemic and regional hemodynamic effects of selective inhibitors of these
PDE
isozymes, CI-930 (0.1-10 mg/kg), an inhibitor of low Km cAMP
PDE
, or zaprinast (3-30 mg/kg), an inhibitor of low Km cGMP
PDE
, was given i.v. to conscious, normotensive rats. The rats were chronically instrumented with vascular catheters and either an ultrasonic transit-time flow probe around the ascending aorta or miniaturized pulsed Doppler flow probes around the superior mesenteric and left renal arteries and the abdominal aorta. CI-930 and zaprinast, at cumulative doses of 3 and 30 mg/kg, respectively, produced comparable reductions in mean arterial pressure (-22 +/- 3 and -19 +/- 4 mm Hg, respectively) and total peripheral resistance (-0.41 +/- 0.07 and -0.42 +/- 0.06 mm Hg/ml/min, respectively) but affected other hemodynamic variables differently. CI-930 at 3 mg/kg increased the heart rate (HR), maximal aortic flow acceleration (dF/dt), and peak aortic flow and decreased the
stroke
volume (SV). Cardiac output (CO) was not affected by CI-930. Zaprinast at 30 mg/kg increased the CO, dF/dt, and peak aortic blood flow. The HR and SV were unaffected by zaprinast. Although both CI-930 and zaprinast increased the dF/dt and peak aortic flow, these parameters were affected more by CI-930 than by zaprinast. CI-930 decreased hindquarter, mesenteric, and renal vascular resistances in a dose-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Differential hemodynamic responses to selective inhibitors of cyclic nucleotide phosphodiesterases in conscious rats. 137 16
The efficacy of the
phosphodiesterase
inhibitor enoximone for reversal of severe postcardiotomy low cardiac output syndrome was investigated in 13 cases of cardiogenic shock refractory to conventional treatment consisting of beta-adrenergic agonists (n = 13) combined with vasodilators (n = 7), and intra-aortic balloon counterpulsation (n = 5). Following a bolus of 1 mg/kg enoximone, cardiac and
stroke
volume indices increased from 1.56 +/- 0.27 l/min/m2 and 16.3 +/- 3.3 ml/m2, respectively, to 2.72 +/- 0.67 and 27.8 +/- 7.1 (both p < 0.001). Mean arterial pressure fell, from 77 +/- 11 to 68 +/- 9 mmHg (p < 0.05), as did atrial filling pressures (LAP and RAP), LAP from 21.3 +/- 5.5 to 15.9 +/- 2.9 and RAP from 16.6 +/- 2.3 to 13.7 +/- 2.1 mmHg (both p < 0.01). The heart rate rose by only 5%. Enoximone therapy was maintained by a continuous infusion (5-7.5 micrograms/kg/min) for 40.6 +/- 8.6 hours (range 14-92). All hemodynamic parameters remained stable throughout treatment. Six patients died of sepsis and/or multiorgan failure but seven were discharged from hospital. Enoximone thus improved hemodynamic performance significantly in cardiogenic shock after open-heart surgery. It also has proved valuable in cardiac failure when conventional therapy was unsuccessful.
...
PMID:Efficacy of phosphodiesterase inhibitor enoximone in management of postcardiotomy cardiogenic shock. 143 45
If the failing left ventricle could be given an effective push, other approaches to the treatment of heart failure would not be needed. We have inotropes only for short-term parenteral use. We have no safe inotrope for chronic oral use. The effect of digitalis is only feeble and the
phosphodiesterase
inhibitors seem to increase mortality from sudden death. Diuretics are dramatic for acute pulmonary oedema and the mainstay for chronic fluid retention but do not improve the pump and by reducing blood volume stimulate the renin angiotensin system to vasoconstriction, further fluid retention and hypokalaemia. Nitrates drop pre-load without reducing blood volume but tolerance is a problem and
stroke
volume does not increase. Reduction of afterload helps the failing ventricle to empty, the pull and output increases. The angiotensin converting enzyme inhibitors (ACEI) are now the cornerstone of heart failure treatment, reducing mortality in severe heart failure (CONSENSUS) and superior to standard vasodilator therapy (V-HeFT-2) at improving the survival of patients with mild to moderate heart failure. ACEI can reduce the incidence of ventricular ectopy and probably do this through improving left ventricular function, from decreasing sympathetic tone, reducing myocardial oxygen demand or increasing serum potassium but ACEI did not diminish the incidence of sudden death in the SOLVD trial despite reducing mortality. Disappointingly little improvement in exercise tolerance and persistence of chronic fatigue in heart failure concentrated attention on the periphery.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:The push, the pull and the periphery. 144 45
Phosphodiesterase III inhibitors have been established in recent years in the therapy of congestive heart failure. Many disadvantages, such as extensive vasodilation and the lack of proven positive inotropic properties combined with thrombepenia and elevation of transaminases, have complicated the handling of the drug in clinical practice. Enoximone, an imidazole derivative, has been demonstrated to be more cardioselective and vasodilation has been found to be less pronounced than with amrinone. As a consequence, research was performed to enhance the cardioselectivity of
phosphodiesterase
III inhibitors by reduction of non-specific cross-reactivity with other phosphodiesterases, and R80122 (Janssen Pharmaceutics, Belgium) was introduced into clinical practice. R80122 ((E)-Ncyclohexal-N-methyl-2[[[phenyl (1,2,3,5-tetrahydro-2 oxoimidazo [2,1b]-quinazolin-7-yl)methylene] amino] oxy] acetamide) is a selective inhibitor of
phosphodiesterase
(
PDE
) IIIc, which is localized in the myocardium. Thus, its inhibition leads to a positive inotropic effect, whereas
phosphodiesterase
IIIRo is found in the vessel wall and causes vasodilation. This study was performed to investigate the hemodynamic profile of R80122 under clinical conditions. Additionally, the intestinal hemodynamics were recorded and changes in intestinal perfusion compared with changes in global hemodynamics. METHODS. The study was thoroughly discussed and approved by the local ethics committee; all patients gave written informed consent. The investigation was performed on ten male patients who were about to undergo elective coronary artery bypass surgery. History, physical examination and laboratory results were within the normal limits and revealed no evidence of liver disease. The usual medication was continued until the day before the operation. Premedication consisted of 2 mg flunitrazepam p.o. in the evening before the operation and 1.5 h before induction of anaesthesia. The determination of hepatic plasma flow was performed by the indocyanine green (ICG) infusion extraction technique using liver vein catheterization. After induction of anaesthesia (MP1), after application of a bolus dose of R80122 (0.3 mg/kg BW) (MP2) and at sternotomy (MP3), hemodynamic data (heart rate, arterial pressure, cardiac output) were recorded and blood samples for the determination of hepatic plasma flow by the concentration of ICG were collected. Anaesthesia was induced with a bolus dose of 0.2 mg/kg BW etomidate, 7 micrograms/kgBW fentanyl and 0.1 mg/kgBW pancuronium and maintained with a continuous infusion of 20 micrograms/min fentanyl, 300 micrograms/min midazolam and mechanical ventilation with O2/N2O at an FiO2 of 0.5. Statistical analysis was performed using the Wilcoxon-Mann-Whitney U test comparing the results after induction of anesthesia (MPI) with those after application of R80122 (MPII) and the results of MPII with those at sternotomy (MPIII). Statistical significance was assumed at P less than 0.05. RESULTS. After the induction of anaesthesia, the median heart rate (HR) was 56/min and did not change after administration of R80122. During sternotomy there was a significant increase in the HR from 64 to 78/min (P less than 0.05). Median arterial blood pressure (MAP) tended to decreased from 91 mm Hg after induction of 77 mm Hg after administration of R80122, although there was no statistical significance because of interindividual differences in the tendencies. At sternotomy, MAP remained unchanged. Cardiac output (CO) increased by 60% after administration of R80122 (P less than 0.01) and did not change during sternotomy. As a consequence of the changes in HR and CO,
stroke
volume (SV) increased by 22% after administration of R80122 (P less than 0.025) and decreased to control values during sternotomy.
...
PMID:[Effects of R80122. The influence of a new phosphodiesterase inhibitor on global and intestinal hemodynamics in coronary surgery patients]. 152 59
The hemodynamic effects of dobutamine, milrinone, and a combination of both drugs were compared intra-individually in 14 patients with severe heart failure (NYHA III: n = 9; NYHA IV: n = 5). Dobutamine (maximum dose: 9 micrograms/kg/min) and milrinone (0.5 micrograms/kg/min) each induced a comparable increase in
stroke
volume index (21 to 29 resp. 21 to 30 ml/m2; mean values; p less than 0.001) and reduction in pulmonary capillary wedge pressure (29 to 22 resp. 28 to 21 mm Hg; p less than 0.001), as well as in systemic (1846 to 1218 resp. 1858 to 1276 dyn s/cm5; p less than 0.001) and pulmonary vascular (301 to 195 resp. 293 to 216 dyn s/cm5; p less than 0.001) resistances. The heart rate rose significantly after dobutamine (92 to 107 min-1; p less than 0.05), but did not change after milrinone (94 to 95 min-1; ns). Neither drug had a significant effect on systemic arterial pressures. The combination of milrinone and dobutamine induced a further significant rise in
stroke
volume index (37 ml/m2; p less than 0.01) when compared to either drug alone. The combination also caused an additional fall in pulmonary capillary wedge pressure (14 mm Hg; p less than 0.01), as well as in systemic (799 dyn s/cm5; p less than 0.001) and pulmonary (133 dyn s/cm5; p less than 0.001) vascular resistances. When compared to dobutamine alone, the combined therapy did not significantly change the heart rate and systemic arterial pressures. The combined administration of a beta-adrenergic agonist and a
phosphodiesterase
inhibitor induces beneficial hemodynamic effects.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:[Additive effects of milrinone and dobutamine in severe heart failure]. 162 7
Forskolin, a diterpene derivative of the Indian plant Coleus forskhohlii, proved to be a marked positive inotropic and vasodilatory compound in animal experiments with a mechanism of action distinct from catecholamines, cardiac glycosides, and
phosphodiesterase
-inhibiting compounds. The cardiovascular effects of forskolin seem to be mediated by a direct stimulatory action at the catalytic unit of sarcolemmal adenylate cyclase. The aim of the present study was to clarify the cardiovascular profile of this compound in 12 patients with stage III (NYHA) congestive cardiomyopathy. The effects of forskolin were investigated by invasive techniques using the thermodilution catheter method and compared to the beta 1-receptor agonist dobutamine and the vasodilator sodium nitroprusside in an intraindividual comparison. Forskolin dose-dependently reduced cardiac pre- and afterload values, and led to a reduction in systolic, diastolic, and mean pulmonary artery pressure as well as pulmonary wedge pressure by greater than 50% concomitant with an increase in cardiac output. There was a slight increase in heart rate. Cardiac
stroke
volume and
stroke
volume index was increased by approximately 70%. The cardiovascular effects of dobutamine and nitroprusside were less pronounced; however, it seemed that a similar hemodynamic profile could be achieved by the combination of both dobutamine and sodium nitroprusside. In view of the rapid development of tolerance toward beta 1-receptor stimulation, forskolin, with its receptor-independent mechanism of action, may be advantageous for the treatment of severe heart failure, especially in patients with catecholamine-insensitive heart failure.
...
PMID:Cardiovascular effects of forskolin (HL 362) in patients with idiopathic congestive cardiomyopathy--a comparative study with dobutamine and sodium nitroprusside. 169 72
To contrast the effect of increasing blood calcium concentrations on the cardiovascular actions of intravenous beta-adrenergic agonists and
phosphodiesterase
inhibitors, 46 patients recovering from aortocoronary bypass surgery received either dobutamine or amrinone both in the presence and absence of a calcium infusion. Cardiac output, systemic arterial pressure, pulmonary arterial pressure, central venous pressure, pulmonary artery occlusion pressure, heart rate, and blood ionized calcium concentration were measured before and during infusions of dobutamine (2.5 and 5.0 micrograms/kg/min) and amrinone (0.75 mg/kg bolus + 10 micrograms/kg/min or 2.25 mg/kg bolus + 20 micrograms/kg/min). After the initial dobutamine infusion period, patients were randomly and blindly assigned to receive either a calcium or placebo infusion, and the dobutamine infusions were repeated. Because of the long duration of amrinone's actions, the amrinone maintenance infusion was continued while randomized, blinded infusion of either calcium or placebo was added. Dobutamine (5 micrograms/kg/min) increased cardiac output from 7.1 +/- 0.3 L/min to 9.1 +/- 0.4 L/min, and increased heart rate from 93 +/- 4 beats/min to 107 +/- 4 beats/min. Systemic vascular resistance decreased and
stroke
volume increased. Dobutamine had no significant effects on other hemodynamic values. Amrinone (2.25 mg/kg bolus + 20 micrograms/kg/min) increased cardiac output from 5.6 +/- 0.4 L/min to 6.9 +/- 0.5 L/min, and increased heart rate from 87 +/- 3 beats/min to 98 +/- 3 beats/min. Amrinone decreased mean arterial pressure, systemic vascular resistance, pulmonary artery occlusion pressure, central venous pressure, and pulmonary artery pressure. Calcium infusion increased arterial pressure (8 to 13 percent) but had no significant effects on any other hemodynamic parameters. Calcium reduced the increase in cardiac output produced by dobutamine by 30 percent, but it did not alter the cardiotonic actions of amrinone. Thus, calcium inhibits the cardiotonic actions of certain beta-adrenergic agonists, most likely by interfering with signal transduction through the beta-adrenergic receptor complex.
...
PMID:Calcium inhibits the cardiac stimulating properties of dobutamine but not of amrinone. 172 65
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