Whole Blood Viscosity Values Research Articles

Comparison of blood viscosity in red-eared sliders (Trachemys scripta) adapted to cold and room temperature

Red-eared sliders (Trachemys scripta) in their northern range undergo hibernation at temperatures of about 5 degrees C, which may result in a profound bradycardia and a drop in blood pressure leading to very slow blood flows. Blood viscosity increases with decreasing temperature and at low shear rates associated with slow blood flows. To investigate the effects of temperature on the blood viscosity of these animals, 20 red-eared sliders were randomly assigned to each of two groups, cold environment (5 degrees C) or room-temperature environment (25 degrees C). At the end of 5 months treatment, hematocrit values, plasma protein concentration, and whole-blood viscosity values were determined for each turtle. Blood viscosity measurements were determined at five shear rates (3.75, 15, 30, 75, and 150 s-1) at 5 degrees C and 25 degrees C for all animals. No significant differences were found in hematocrit or plasma protein values between cold-adapted and room temperature-adapted animals. Whole-blood viscosity between groups at any shear rate at a temperature of 5 degrees C was also nonsignificant. The only significant difference in blood viscosity between turtles adapted to cold and room temperature occurred at a shear rate of 3.75 s-1 at 25 degrees C. The whole-blood viscosity of red-eared sliders, whether adapted to cold or to room temperature, tended to be lower as compared to other vertebrates under similar conditions of temperature, shear rate, and hematocrit. This innate lower blood viscosity may compensate for the potential detrimental effects on blood viscosity brought about by the low temperatures and decreased shear rates that occur in these animals during hibernation.

Comparison of blood viscosity in red‐eared sliders (Trachemys scripta) adapted to cold and room temperature

Red-eared sliders (Trachemys scripta) in their northern range undergo hibernation at temperatures of about 5°C, which may result in a profound bradycardia and a drop in blood pressure leading to very slow blood flows. Blood viscosity increases with decreasing temperature and at low shear rates associated with slow blood flows. To investigate the effects of temperature on the blood viscosity of these animals, 20 red-eared sliders were randomly assigned to each of two groups, cold environment (5°C) or room-temperature environment (25°C). At the end of 5 months treatment, hematocrit values, plasma protein concentration, and whole-blood viscosity values were determined for each turtle. Blood viscosity measurements were determined at five shear rates (3.75, 15, 30, 75, and 150 s–1) at 5°C and 25°C for all animals. No significant differences were found in hematocrit or plasma protein values between cold- adapted and room temperature-adapted animals. Whole-blood viscosity between groups at any shear rate at a temperature of 5°C was also nonsignificant. The only significant difference in blood viscosity between turtles adapted to cold and room temperature occurred at a shear rate of 3.75 s–1 at 25°C. The whole-blood viscosity of red-eared sliders, whether adapted to cold or to room temperature, tended to be lower as compared to other vertebrates under similar conditions of temperature, shear rate, and hematocrit. This innate lower blood viscosity may compensate for the potential detrimental effects on blood viscosity brought about by the low temperatures and decreased shear rates that occur in these animals during hibernation. J. Exp. Zool. 281:157–163, 1998. © 1998 Wiley-Liss, Inc.

Discussion on the relation between normal value of whole blood viscosity (230s−1) of Chinese women and geographical factors

Discussion on the relation between normal value of whole blood viscosity (230s−1) of Chinese women and geographical factors

ＰＧＩ２誘導体（ＴＲＫ‐１００）の生体内レオロジーに対する影響

Effect of PGI2 analogue (TRK-100) on haemorheological factors in patients with peripheral vascular disease.The effect of prostaglandin I2 analogue (TRK-100) on haemorheological factors (red cell deformability, whole blood viscosity, plasma viscosity, and plasma c-AMP) in 12 patients with peripheral vascular disease (Buerger's disease, arteriosclerosis obliterans and Raynaud's syndrome) were studied.Although red cell deformability was reduced in patients with peripheral vascular disease, TRK-100 (120μg/day, 6 weeks) was shown to be effective in improving the reduced red cell deformability.However, there was no statistical change in the values of whole blood viscosity, plasma viscosity or plasma c-AMP in this study.

Maternal whole blood viscosity in pregnancy hypertension.

Hemoconcentration is prominent in preeclampsia. Concomitant changes in the flow properties of maternal blood, i.e. in whole blood viscosity (WBV), might be related to the occurrence of fetal or maternal complications. To test this hypothesis, WBV was estimated in 228 pregnancies. Patients were assigned to one of four groups according to maximum diastolic blood pressure. Significantly higher WBV values were found in the more hypertensive groups throughout pregnancy. WBV data, obtained between 26 and 36 weeks of amenorrhea, contributed significantly, independently of hypertension, to the prediction of fetal outcome. With regard to maternal complications, no significant contribution of WBV data could be established independently of blood pressure. The results support the hypothesis that WBV is a determining factor in the efficacy of placental perfusion.

Correlation between umbilical vein blood flow and umbilical blood viscosity in normal and complicated pregnancies

Umbilical vein blood flow (UVBF) was studied during the last 24 h before delivery using a combination of real-time and Doppler ultrasonic equipment in 64 normal and pathological pregnancies and the results were correlated with the values of whole blood viscosity taken from the umbilical vein after delivery. UVBF was reduced in the subgroup with chronic fetal distress (n = 14) (P less than 0.001) and the hypertensive pregnancies (n = 17) (P less than 0.05), whereas umbilical blood viscosity was increased only in the subgroup with chronic fetal distress (P less than 0.01) as compared with the normal pregnancies (n = 24). A significant positive correlation was observed between the umbilical blood viscosity and haematocrit values in all the groups of patients. UVBF and blood viscosity had a significant negative correlation in chronic fetal distress (P less than 0.001) and in hypertensive pregnancies (P less than 0.05), but not in normal or diabetic pregnancies (n = 9). Thus haemoconcentration leading to increased fetal blood viscosity may act as an aetiological factor in the reduction of UVBF in developing fetal distress.

Epidemiologic findings on blood viscosity

In order to obtain basic knowledge about blood viscosity, which is changed by a variety of factors and disease, this study examined variations in blood viscosity. Sex, age, season, smoking, blood pressure, vibration syndrome, various diseases and exposure to cold were considered.Blood viscosity levels in several groups were measured with a cone-plate viscometer. The groups consisted of male and female healthy non-smokers among hospital employees, male inhabitans of a mountain village, male subjects with the vibration syndrome found in union shop forestry workers, pulp manufacturing company employees and male and female hospitalized patients.The following results were obtained:1) In healthy non-smokers, there were no significant variations in whole-blood viscosity and plasma viscosity with regard to age and season, but whole-blood viscosity levels in males were significantly higher than those in females, at all shear rates. A significant positive correlation was observed beetween whole-blood viscosity and Ht.2) In an analysis of the influence of smoking, hypertension and vibration syndrome on whole-blood viscosity, three way experimental lay out, smoking, hypertension and vibration syndrome were all found to increase whole-blood viscosity. An interaction between smoking and hypertension was demonstrated which increased whole-blood viscosity. Morever, the same analysis carried out for plasma viscosity, demonstrated that the factors which increased plasma viscosity were again smoking and hypertension.3) Whole-blood viscosity values in healthy non-smokers before exposure to cold showed lower values than in smokers and hypertensives, morever, whole-blood viscosity levels during exposure to cold in healthy non-smokers increased greatly compared to those in smokers and hypertensives.4) Whole-blood viscosity levels during exposure to cold in non-hypertensives with vibration syndrome increased greatly, but whole-blood viscosity values in hypertensives with vibration syndrome did not increase. Whole-blood viscosity values in hypertensives with vibration syndrome were already high before exposure to cold.5) With regard to cold exposure, blood viscosity changes in subjects with or without vibration syndrome showed a similar tendency in both the exposed and non-exposed arms.6) Whole-blood viscosity values in myocardial infarction, essential hypertension and diabetes mellitus were increased, and those in collagen disease and anemia were decreased. Plasma viscosity in myocardial infarction, coronary arteriosclerosis, cerebral infarction, essential hypertension, collagen disease and diabetes mellitus were increased, and those in anemia were decreased.

Maternal and fetal blood viscosity throughout normal pregnancy

SummaryThe changing values of whole blood viscosity and its major determinants, haematocrit, plasma fibrinogen, total serum protein, plasma viscosity and erythrocyte deformability, were followed throughout and after normal pregnancy in a serial study of 50 patients.In a cross-sectional study of the same parameters in cord blood samples from 170 fetuses at varying gestations, the haemorheological profile of fetal blood was defined. The significance of these haemorheological measurements in the changing haemodynamics of pregnancy and as a background for the study of pathological pregnancy is discussed.

Viscosity and retinal vein thrombosis.

Whole-blood and plasma viscosity with haematological and biochemical investigations were measured in 44 patients with retinal vein occlusion. The patients were subdivided on the basis of fluorescein angiographic findings into: 1. Those with large areas of capillary non-perfusion. 2. Those with small areas of capillary non-perfusion. 3. Those with an intact capillary pattern. Capillary non-perfusion in retinal vein occlusion is associated with a higher morbidity owing to the complications of retinal neovascularization. Significantly higher values of whole-blood viscosity, packed cell volume, and yield stress have been found in patients with capillary non-perfusion than in those without. These differences may be of critical importance during the episode of retinal vein occlusion and suggest an aetiological factor in the development of capillary non-perfusion. Higher whole-blood and plasma viscosity values and plasma fibrinogen levels have also been shown in the whole retinal vein occlusion group compared with a control group of 30 individuals. These differences may be a factor in the development of retinal vein occlusion but their precise role is difficult to evaluate. Further biochemical investigations in the vein occlusion group supported the strong association with arterial disease and suggested a higher incidence of biochemical abnormalities in those patients with capillary non-perfusion.