[The effect of co-dergocrine mesylate on erythrocyte deformability of hyperosmolar blood in vitro]. / Beeinflussung der Erythrozyten-Verformbarkeit hyperosmolaren Blutes in vitro durch Co-Dergocrinmesilat.

Addition of low doses of co-dergocrine mesilate (CAS 8067-24-1), a drug containing a mixture of hydrated ergot alkaloids to hyperosmolar blood in vitro leads to a dose-dependent increase in erythrocyte filterability through a 8 mu filter system. The concentrations of co-dergocrine mesilate used in the present experiments ranged from 0.04675-6.0 mg/100 ml blood. Blood samples were incubated for 90 min at 37 degrees C, measuring temperature was 37 degrees C. It could be shown that the drug-induced increase in erythrocyte filterability was not dependent on the presence of leucocytes. At higher osmolarity values, when the erythrocytes were more rigid, higher concentrations of codergocrine mesilate were needed in order to obtain a comparable improvement in red cell deformability.

Exercise-induced variations in muscle tissue oxygen pressure in claudicants: effects of buflomedil.

The amount of oxygen actually supplied to the ischemic muscle tissue of patients with intermittent claudication was quantified before and after a standardized pedal ergometric test. Muscle tissue pO2 was measured with micro-platin needle electrodes directly in the lower limb muscles at rest and 3, 10, 20 and 60 min after a 4-min work load. Time-dependent variations in the behavior of pO2 values as well as changes in the shapes of pooled pO2 histograms make it possible to monitor the effect of therapeutic measures. In claudicants (stage IIb) with ascertained occlusions or stenosis of the femoral artery or the pelvis region, it was demonstrated that the delayed increase in tissue pO2 after exercise could be improved by the infusion of 400 mg buflomedil. Comparison between the time-related pooled histograms confirmed improvement of oxygen supply under the influence of this drug.

[Effect of stepwise hypervolemic versus isovolemic hemodilution in patients with intermittent claudication on muscle oxygen pressure during exercise]. / Einfluss einer stufenweisen hypervolämischen versus isovolämischen Hämodilution bei Patienten mit Claudicatio intermittens auf den Muskelgewebesauerstoffdruck unter Belastungsbedingungen.

In patients with intermittent claudication and concomitant high hematocrit values a stepwise hypervolemic hemodilution versus isovolemic hemodilution (intravenous infusion of 500ml 10% hydroxyethylstarch solution (HES)(mean molecular weight 200.000/substitution degree 50%) or vensection and subsequent infusion of 10% HES (200/0.5)) were performed intraindividually. Measurements of muscle tissue oxygen pressure (pO2) values using a standardized pedalergometric exercise test as well as the pain free walking distance using a standardized treadmill were performed. Optimal results of muscle tissue oxygen pressure (pO2) behaviour after pedalergometric exercise test as well as muscular performance on the treadmill were found using isovolemic hemodilution at an average hematocrit value of 40.60%. In contrast, hypervolemic hemodilution at a comparable hematocrit level (40.50%) induced a "retarded reactive hyperoxia" and only a moderate increase of painfree walking distance.

Optimal hematocrit in patients with intermittent claudication. Exercise-induced muscle tissue oxygen pressure after stepwise hemodilution.

In patients with severe intermittent claudication and concomitant high hematocrit values a hypervolemic (stepwise infusion of 500 ml 10% hydroxyethylsolution: mean molecular weight 200.000/substitution degree 0.5) or isovolemic hemodilution (stepwise venesection and subsequent infusion of 10% hydroxyethylstarch solution 200/0.5) was performed intraindividually. Measurements of muscle tissue oxygen pressure (pO2) values using a standardized pedalergometric exercise test were performed. The optimal results of muscle tissue pO2 behaviour after pedalergometric exercise were found at average hematocrit values of 40%-41% when isovolemic hemodilution was applied. Hypervolemic hemodilution improves muscle tissue oxygen supply at rest, but shows a retarded reactive hyperoxia under exercise conditions. Thus it is likely that in patients with severe intermittent claudication an optimal tissue oxygen supply can be obtained in the case of isovolemic hemodilution at hematocrit values of about 40-41%.

[Effect of a 10% and 6% hydroxyethyl starch solution (molecular weight 200,000/0.62) in comparison with a 10% dextran solution (molecular weight 40,000) on flow properties of blood and tissue oxygen pressure in patients with intermittent claudication]. / Einfluss einer 10%igen und 6%igen Hydroxyäthylstärkelösung (MG 200,000/0.62) im Vergleich mit einer 10%igen Dextranlösung (MG 40,000) auf die Fliesseigenschaften des Blutes und den Gewebesauerstoffdruck von Patienten mit Claudicatio intermittens.

In a randomized, double-blind cross-over study in 10 patients with intermittent claudication, 2 concentrations (6% and 10%) of a hydroxyethyl starch (HES) solution of mean molecular weight 200,000 and of substitution degree 0.62 were compared to a 10% low-molecular-weight dextran solution of mean molecular weight 400,000. In addition to several hemorheological parameters, the behavior of the tissue oxygen pressure directly in the ischemic lower leg muscles of patients with chronic arterial occlusive vascular disease (stage IIb) was examined. 500 ml of the solutions described above were infused over a period of 30 min. Parameters such as tissue oxygen pressure and flow properties of blood were determined before infusion, immediately upon terminating infusion and 30, 60, 90, 120 and 180 min thereafter. A reduction of hematocrit values and of whole blood viscosity was observed, which was most pronounced with the 10% solutions. The plasma viscosity increased significantly with both the 10% dextran solution as well as with the 10% HES solution. This behavior was less pronounced with the 6% solution. Measurement of the erythrocyte aggregation yielded an increase in values after infusion which was more significant for the 10% than for the 6% HES solution. The tissue oxygen pressure, as a measure of the tissue oxygen supply, remained more or less constant during hypervolemic hemodilution, despite reduced hematocrit values in the dextran group and in the 10% HES group.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of videofilm-induced emotional stress on the flow properties of blood.

The hemorheologic effects of emotional stress induced by a videofilm were investigated in 10 healthy volunteers. Blood samples were obtained from the antecubital vein before, during, and after the end of the videofilm. Blood pressure and heart rate were simultaneously measured. There was a statistically significant increase in blood and plasma viscosity during and immediately after the end of the videofilm, which correlated with an increase in plasma catecholamine concentrations. This hemorheologic behavior can be explained as a result of an endogenous hemoconcentration that takes place if the Starling equilibrium of intravascular vs extravascular fluid is changed. These observations could lead to new aspects of the pathophysiology of acute myocardial infarction initiated by severe emotional stress.

Influence of pentoxifylline on muscle tissue oxygen tension (pO2) of patients with intermittent claudication before and after pedal ergometer exercise.

Ten patients with Stage II chronic arterial occlusive disease (intermittent claudication) took part in a randomized, intraindividual crossover study involving acute intravenous administration of 200 mg pentoxifylline or physiological saline solution (placebo). The tissue oxygen tension (pO2) response (pO2 kinetics) following treatment with placebo revealed a nominal but statistically nonsignificant increase in arithmetic mean and median pO2 immediately after the end of exercise. Values thereafter reverted approximately to the initial values recorded at rest. Comparison of the pooled pO2 histograms during the individual periods before and after the end of exercise, however, revealed a broadening of the histogram base, reflecting both higher pO2 values and, more particularly, increased numbers of hypoxic and anoxic pO2 values. This is interpreted as an expression of nonhomogeneous capillary perfusion (maldistribution). Following administration of pentoxifylline to the same patients, there was a statistically significant increase in mean and median pO2 at ten and twenty minutes after the end of exercise. Even after thirty and sixty minutes, these values were in some cases still clearly higher than the initial preexercise values. Study of the pooled pO2 histograms discloses a right shift compared with the initial preexercise histograms. This suggests that pentoxifylline exerts a positive effect on maldistribution by making capillary perfusion more homogeneous. The results support the conclusion that, in the context of reactive hyperemia after muscular exercise, tissue oxygen supply is markedly improved by pentoxifylline in comparison with saline solution. The measurement of tissue pO2 before and at intervals after pedal ergometer exercise is a new objective technique for assessing the efficacy of blood flow-promoting therapy, permitting close simulation of the pathophysiological situation in the muscles of the lower leg in intermittent claudication.

[Improvement of the flow properties of the blood of patients by low-molecular hydroxyethyl starch (Expafusin)]. / Verbesserung der Fliesseigenschaften des Blutes von Patienten durch niedermolekulare Hydroxyäthylstärke (Expafusin).

10 patients with various diseases causing elevated ESR-values and impaired flow properties of blood received infusions of 500 ml of low molecular weight hydroxyethylstarch (HES 6%, Expafusin) within approximately 30 minutes. Measurements of rheological parameters for several hours after infusion showed a statistically significant decrease of apparent whole blood viscosity and of plasma viscosity. RBC aggregation was slightly, but statistically significantly reduced, whereas RBC filterability remained unchanged. These data obtained with blood from patients with altered flow properties of blood agree very well with former results obtained in healthy volunteers.

[Effect of an infusion with middle molecular weight hydroxyethyl starch (HAES-steril 10%) on the flow properties of blood in healthy probands]. / Untersuchung über dex Einfluss einer Infusion von mittelmolekularer Hydroxyäthylstärke (HAES-steril 10%) auf die Fliesseigenschaften des Blutes gesunder Probanden.

Ten healthy volunteers received infusions of 500 ml of a 10% solution of middle-molecular-weight hydroxy-ethyl-starch (HES 200, HAES-steril 10%) within 30 min. Measurements of hemorheological parameters before and up to 3 hrs after infusion revealed a statistically significant decrease of whole-blood viscosity and a slight, but also statistically significant increase of plasma viscosity. RBC filterability and RBC aggregation remained unchanged. The data presented show that despite of a relatively high molecular weight of the infused HES-solution which is responsible for the relatively long intravascular persistence, the flow properties of blood as a whole are positively influenced.

Erythrocyte filtration and smoking.

Erythrocyte filterability may be influenced by 'acute' smoking with subsequent changes of RBC filterability and by chronic inhalation of cigarette smoke which may lead to chronic alterations. To evaluate chronic alterations of RBC deformability we compared the erythrocyte filtration rates of 60 young, healthy chronic smokers (30 female, 30 male) with those of 60 young, healthy non-smokers (again 30 female and 30 male). The comparison showed a higher filtration rate in the male non-smokers group than in the group of the male smokers, the difference however was not statistically significant. Female smokers and non-smokers did not show any noticeable difference in their RBC filtration rates.

[Improvement of blood viscosity after infusion of low-molecular hydroxyethyl starch (Expafusin) in healthy subjects]. / Verbesserung der Fliesseigenschaften des Blutes nach Infusion von niedermolekularer Hydroxyäthylstärke (Expafusin) bei gesunden Probanden.

In healthy volunteers, 500 ml of a 6% low molecular weight hydroxyethyl starch solution (Expafusin) was infused intravenously within 30 minutes. Blood samples for the measurement of rheological parameters were obtained before and after the infusion. Blood and plasma viscosity were significantly decreased after the infusion of HES. Red cell deformability as measured by a filtration technique was slightly improved. Red cell aggregation as measured by a light transmission method was markedly reduced. Repeated infusion of 500 ml Expafusin indicates that the improvement of the flow properties of blood can be maintained for more than 3 hours.

[Rheology of the blood during treatment of hypertension with xipamide (author's transl)]. / Fliesseingenschaften des Blutes bei Behandlung der essentiellen Hypertonie mit Xipamid.

The possible effect of xipamide on flow properties of blood were studied in groups of eight patients each with essential hypertension. It was demonstrated that 10 mg xipamide (a long-acting diuretic) given daily had no deleterious effect on flow property, while 20 mg daily produced a haemoconcentration which negatively affected it, apparently in relation to the urine volume excreted per unit time. At higher dosages the effect on blood flow properties was shifted in time, which indicates that the increased diuresis in the first day leads to a cumulative effect on the flow properties of the blood. Erythrocyte deformability was not affected. It is possible that combined preparations which contain a diuretic should be specially examined with respect to any undesirable effect on flow properties of the blood.