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Results for “BLOOD VISCOSITY”

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PubMed2006

Influence of parenteral fat emulsion Intralipos and citric acid on blood viscosity and erythrocyte morphology in vitro.

In most studies fat emulsion had been administered by enteral route. Recently a parenteral soybean-oil emulsion has been developed. In this study we assessed the effects of a parenteral soybean-oil emulsion (Intralipos) and citric acid on blood rheology and erythrocyte morphology in vitro. Porcine blood was incubated in vitro with increasing concentrations of fat emulsion Intralipos and citric acid at 37 degrees C for 1h. Viscosity of plasma and whole blood was measured using a FASCO-2050 digital viscometer. Red blood cell morphology was examined by light microscopy. The viscosity of whole blood represented an ascending dose-dependence for different Intralipos concentrations at high shear rate of 90 and 225 s(-1), however, it decreased with citric acid concentrations. On the other hand, the whole blood viscosity also declined with citric acid concentrations in presence of 30% Intralipos (v/v), and there is a minimal viscosity at 0.67% citric acid (v/v). There are some thorns on the blood membrane at 40% Intralipos as compared with control (no Intralipos addition), which indicates the Intralipos compound may affect blood cell membranes, and resulted in whole blood viscosity increase. We concluded that the intravenous soybean-oil preparation Intralipos interacts with the erythrocyte membrane, and citric acid could alleviate the whole blood viscosity.

Animals↗
PubMed1997

Hypoalbuminemia causes high blood viscosity by increasing red cell lysophosphatidylcholine.

Albumin deficiency is accompanied by a reduction in red cell deformability and blood hyperviscosity. Albumin deficiency increases plasma fibrinogen and triglyceride levels and may alter red cell membrane lipid composition. These options, which could all contribute to reduced red cell deformability (RCD) and hyperviscosity, were studied in the Nagase analbuminemic rat (NAR), a mutant Sprague Dawley rat (CON), characterized by normal total protein levels, with an absolute deficiency of albumin, but elevated levels of non-albumin proteins and hyperlipidemia. Plasma protein-binding of the polar phopholipid lysophosphatidylcholine (LPC) was markedly decreased. LPC comprised only 26 +/- 1% of total plasma phospholipids as compared to 42 +/- 2% in CON. NAR red cells in CON plasma had a viscosity that was similar to CON red cells in CON plasma. Conversely, CON red cells in NAR plasma show an increased viscosity as compared to CON red cells in CON plasma. The maximum deformation index of both NAR and CON red cells was markedly decreased in NAR plasma as compared to either NAR or CON cells in CON plasma (0.04 +/- 0.03 and 0.02 +/- 0.02 vs. 0.22 +/- 0.06 and 0.15 +/- 0.04, respectively; P < 0.05). Thus, plasma composition causes hyperviscosity and reduced RCD in NAR. Fibrinogen is not responsible since red cells in serum and red cells in plasma had a similar viscosity and differences in viscosity and RCD between NAR and CON were maintained. Plasma triglycerides are also not responsible since the viscosity of red cells in serum with a 50% reduction in triglycerides was not reduced. LPC levels in red cells were increased in NAR (8.7 +/- 0.2 vs. 5.5 +/- 0.3% of total phospholipids; P < 0.01). Adding albumin to NAR blood dose-dependently decreased whole blood viscosity, despite marked increases in plasma viscosity, and increased RCD of NAR cells (from 0.04 +/- 0.03 to 0.21 +/- 0.01; P < 0.05). There was also some effect on CON RCD of similar albumin addition to CON blood (from 0.15 +/- 0.04 to 0.29 +/- 0.03; P < 0.05). Adding albumin to NAR blood reduced red cell LPC content and increased plasma LPC content in a dose-dependent fashion, whereas there were only slight effects of adding albumin to CON blood. There was a reciprocal relation between red cell LPC and the other polar phospholipids in the red cell membrane, probably indicating exchange. The maximum deformability index of either NAR or CON cells was not affected much by adding LPC to CON plasma (NAR, from 0.22 +/- 0.06 to 0.18 +/- 0.10; CON, from 0.15 +/- 0.04 to 0.12 +/- 0.05; NS), whereas adding LPC to NAR plasma caused the red cells to become rigid. Adding LPC to CON red cells in NAR plasma caused a much stronger increase in relative LPC content (from 6.6 +/- 0.7 to 10.9 +/- 0.9%; P < 0.05) than adding LPC to CON red cells in CON plasma (from 5.6 +/- 0.4 to 6.4 +/- 0.8%; NS). Thus, in the absence of albumin, LPC in red blood cells is increased. As a consequence of the latter, RCD is decreased and whole blood viscosity increased. Alterations in red cell phospholipids are far more important than increases in plasma fibrinogen or triglycerides in determining hyperviscosity of blood and reduced RCD in NAR.

Animals↗
PubMedDate not supplied

[Action of dopamine on blood flow of the limbs and on blood viscosity (author's transl)].

The observation of several cases of gangrene in the lower limbs of subjects treated with an infusion of dopamine has encouraged the authors to study the action of the drug, in a dose capable of increasing the arterial pressure, on the blood flow in the lower limbs and on the viscosity of the blood in a group of normal middle aged subjects. A significant reduction in the values of the blood flow with a simultaneous increase in the blood viscosity was observed. There results confirm the ischemic action of the drug with the doses used at the muscular and cutaneous level in the lower limbs.

Blood Circulation↗
PubMed1995

Effects of acute psychological stress on serum lipid levels, hemoconcentration, and blood viscosity.

BACKGROUND: While there is substantial evidence that psychological stress enhances risk for coronary artery disease, the mechanisms underlying such an influence remain unclear. We examined the effects of short-term psychological stress on serum lipid levels, hemoconcentration, fibrinogen level, and plasma viscosity. METHODS: Forty-four healthy young adults were randomly assigned to perform a distinctly frustrating cognitive task for 20 minutes (stress condition) or to rest quietly for the same period (control condition). RESULTS: Relative to controls, stressed subjects showed significant increases in blood pressure and heart rate; total, low-density, and high-density lipoprotein cholesterol levels; hematocrit; hemoglobin level; and total protein concentration. Stressed subjects also showed significant reductions in plasma volume and increased plasma viscosity and estimated whole-blood viscosity compared with controls. A similar trend in fibrinogen level was not statistically significant. Individual differences in blood pressure and heart rate response to stress correlated highly with changes in total cholesterol levels and hematocrit. CONCLUSIONS: Our investigation provides further evidence that exposure to short-term mental stress elicits hemoconcentration with associated increases in serum lipid concentrations, hemostatic factors, and blood viscosity.

Acute Disease↗
PubMed1993

Blood viscosity, fibrinogen, and activation of coagulation and leukocytes in peripheral arterial disease and the normal population in the Edinburgh Artery Study.

BACKGROUND: Increased blood and plasma viscosity, hematocrit, fibrinogen, and activation of coagulation and leukocytes have been reported in patients with claudication; however, their associations with symptomatic and asymptomatic peripheral arterial disease have not been reported in an epidemiological study. METHODS AND RESULTS: Blood and plasma viscosity, hematocrit, fibrinogen, urinary fibrinopeptide A, plasma leukocyte elastase, and uric acid were measured in a random sample of 1,581 men and women aged 55-74 years in Edinburgh, Scotland, and related to peripheral arterial stenosis (ankle-brachial systolic pressure index, ABPI) and to lower limb ischemia (intermittent claudication and reactive hyperemia test). Each variable (except fibrinopeptide A) was significantly related to prevalent symptomatic and asymptomatic peripheral arterial disease. On multivariate analysis, blood viscosity (p < 0.05) and fibrinogen (p < 0.01) were independently associated with peripheral arterial narrowing (ABPI); a positive interaction was found between fibrinogen and smoking in the association with ABPI. Plasma viscosity was associated with claudication in the presence of a given degree of arterial narrowing (odds ratio of claudication in top quintile compared with bottom quintile of plasma viscosity, 3.35; 95% CI, 1.32, 8.51). Leukocyte elastase and uric acid were each associated with reactive hyperemia independently of arterial narrowing (p < 0.01). CONCLUSIONS: Blood rheological factors and leukocyte activation as well as arterial narrowing are associated with lower limb ischemia in the general population and may be implicated in its pathogenesis.

Aged↗
PubMed1978

Blood viscosity in the normal newborn baby.

A viscometer was tested and the results were found to be accurate and reproducible for the ranges encountered in neonates. The viscosity was determined in 80 cord blood samples and the mean and 2 standard deviations (2SD) were calculated at each shear rate. Changes in viscosity increased from birth to 12 hours, and then gradually decreased over the next 72 hours. The results are in keeping with the accepted normal values in the newborn.

Blood Viscosity↗