[Effect of prostacyclin on erythrocyte deformability and blood viscosity]. / Effetto della prostaciclina sulla deformabilità dei globuli rossi e sulla viscosità ematica.

The aim of our research was to investigate the effect of prostacyclin (PGI2) on red blood cell deformability and blood viscosity. Ten non-smokers healthy subjects (aged from 25 to 40) were examined. Different PGI2 concentrations were added to the blood sample and then red blood cell deformability and blood viscosity were measured: 1.2 and 2.4 ng/ml PGI2 concentrations, corresponding to plasma PGI2-like activity in man, increased red blood cell deformability and reduced blood viscosity. The PGI2 capacity of affecting red blood cell deformability and blood viscosity seems to be of clinical interest in conditions where the PGI2 production is reduced, such as ischemic heart disease, peripheral artery disease and diabetes mellitus.

[Hemorrheological changes in peripheral obliterative arterial diseases]. / Le alterazioni emoreologiche nell'arteriopatia obliterante periferica.

The relationships between blood rheology and peripheral arterial disease are reviewed. The connections between abnormal blood rheology and peripheral arterial disease are discussed considering the opinions of the enthusiastic and skeptic rheologists. A prospective for future investigations is also proposed.

[Relation of blood viscosity, plasma viscosity and hematocrit]. / Rapporti fra viscosità ematica, viscosità plasmatica ed ematocrito.

The results from 398 consecutive measurements of blood viscosity, plasma viscosity and hematocrit were submitted to a statistical analysis. Hematocrit appeared to be the main determinant of blood viscosity, even though its influence was not so strong as illustrated in previous investigations. The correlation between blood viscosity and hematocrit appeared strictly connected with the red cell amount of the blood sample, being higher when the latter exceeded its physiological range; this correlation disappeared when red blood cell amount was strongly reduced, while the correlation between plasma viscosity and blood viscosity had an opposite behaviour. From these results we can conclude that correlations between hematocrit and plasma viscosity with blood viscosity have opposite trends and that a reciprocal interference is often present.

[A small subpopulation of rigid erythrocytes changes the erythrocyte filtration test]. / Una piccola sottopopolazione di emazie rigide altera il test della filtrazione eritrocitaria.

By means of the filterability test of Reid et al., the influence of a subpopulation of rigid erythrocytes (5% and 2.5%, respectively) was studied using Nucleopore polycarbonate membranes with pore size of 5 mu and diameter of 13 mm. The addition of 5% and 2.5% of rigid red cells delays the erythrocyte filtration times and alters the red cell deformability index. The meaning of the obtained data is discussed.

[The lack of correlation between erythrocyte filtration parameters and other hemorrheological parameters]. / Sulla non correlazione fra parametri della filtrazione eritrocitaria ed altri parametri emoreologici.

The findings of 300 consecutive measurements of erythrocyte filterability, whole blood viscosity, plasma viscosity, hematocrit, mean corpuscular volume and white blood cell count have been statistically analyzed in order to find a possible correlation between these parameters. No correlation between erythrocyte filterability, whole blood viscosity, plasma viscosity, hematocrit, mean corpuscular volume and white blood cell count was found. Some hypotheses are enunciated to explain such absence of correlation. The meaning of erythrocyte filtration test is still unclear.

[Hemorrheological changes induced by submaximal exertion in subjects with insulin-dependent diabetes mellitus]. / Modificazioni emoreologiche indotte da uno sforzo submassimale in soggetti con diabete mellito insulinodipendente.

The influence of an acute physical exercise on hemorheological parameters in insulin-dependent diabetes mellitus in not actually known. We have examined the behavior of hemorheological parameters and other laboratory findings such as blood glucose, blood lactic acid, O2 and CO2 venous pressure and venous pH before and after a submaximal physical exercise standardized by ECG monitoring and by means of an 'oxygen consumption computer'. The work load was significantly lower in diabetic patients than in normal control subjects. On the other hand, changes in hemorheological parameters were more evident in diabetic patients. The significance of these findings is also discussed.