Clinical Hemorheology and Microcirculation - Volume 16, issue 1

Authors: Battistelli, S. | Gori, S. | Borgogni, T. | Manasse, G. | Guerrini, M.

Article Type: Research Article

Abstract: We studied the behaviour of plasma endothelin levels in 7 elderly patients with critical limb ischemia, during iloprost infusion with the aim to clarify both the interaction among various vasoactive endothelial substances and the endothelin importance in atherosclerotic disease development. Iloprost (diluted with saline solution in a concentration of 200ng/ml) was administered intravenously, from 30 to 40 ml/h, for six hours/day and for 4 weeks. Plasma endothelin concentration was determined on the 4th day of treatment at time intervals of 0, 2, 4, 6 and 8 hours: i.e. before the beginning of the infusion, then every two hours till the …sixth hour and two hours after the end of iloprost infusion. The control group was composed by 7 subjects matched for age affected by peripheral obliterant arterial disease at the I and II Fontaine stage: only saline solution was administered to them. The mean ± SD plasma endothelin level of patients in iloprost infusion was 5.40 ± 1.23 pg/ml at T0, 4.24 ± 0.72 pg/ml at the second hour, 4.22 ± 0.74 pg/ml at the fourth hour, 4.24 ± 0.22 pg/ml at the sixth hour and 4.49 ± 0.58 pg/ml at eighth hour. The difference between basal endothelin level and that of the second, fourth and sixth hour was statistically significant (p<0.05) while that of the eighth hour was not. In the control group the means ± SD plasma endothelin levels were respectively 5.23 ± 0.55 pg/ml, 4.88 ± 1.39 pg/ml, 5.44 ± 1.51 pg/ml, 5.10 ± 0.86 pg/ml and 5.60 ± 1.64 pg/ml at the same intervals The difference between the basal endothelin level and the successive ones was not statistically different. In atherosclerosis the endothelial contracting factors become more important whereas the formation and/or effects of the relaxing factors are impaired. Iloprost infusion, therefore, may restore physiological equilibrium among various vasoactive substances, so that tissue perfusion is further improved. Show more

DOI: 10.3233/CH-1996-16111

Citation: Clinical Hemorheology and Microcirculation, vol. 16, no. 1, pp. 57-62, 1996

Authors: Müller, G. H. | Schmid-Schönbein, H.

Article Type: Research Article

Abstract: A Couette device was used for the examination of the flow behaviour exhibited by haemoglobin-A (Hb-A) solutions; the applied shear rates ranged from 0.624 x 10−3 through 4.59 s−1 . The degree of O2 - saturation (SO2 ) was either above 90% (“oxyhaemoglobin-A” or OxyHb-A) or below 10% (“deoxyhaemoglobin-A” or DeoxyHb-A). Besides O2 ; K+ , Ca2+ and 2,3-bisphosphoglycerate (2,3-BPG) were used as additional effectors of haemoglobin-A Thus, it has been possible to demonstrate: 1) The flow properties of OxyHb-A are strict Newtonian and are independent of any other effector added to the solutions. 2) The …reduction of SO2 does not alter the linear torque - shear rate relationship as known for OxyHb-A. 3) K+ at 0.3 mmol/g DeoxyHb-A does not interfere with the Newtonian behaviour of DeoxyHb-A. 4) Ca2+ at 4 μmol/g DeoxyHb-A has no measurable influence on DeoxyHb-A rheology; at 24 μmol/g DeoxyHb-A, however, a fourfold rise in the viscosity of DeoxyHb-A was observed. 5) The addition of 2,3-BPG at fractions of 20 and 30 μmol/g DeoxyHb-A led to a 1.4 - fold increase in DeoxyHb-A viscosity for solutions with a DeoxyHb-A concentration below 32 g/100 ml; above 33 g/100 ml, however, the increase was 2.3 - fold if 2,3-BPG was present at the high relative concentration. 6) Microscopically, particle formation has been ascertained for the cases of increased viscosity in 4) and 5). This development of heterogeneity proved to be a reversible process on reoxygenation. Show more

Keywords: human haemoglobin-A, polymerization, deoxygenation, viscometry, calcium, 2,3-bisphosphoglycerate, erythrocyte

DOI: 10.3233/CH-1996-16112

Citation: Clinical Hemorheology and Microcirculation, vol. 16, no. 1, pp. 63-73, 1996

Article Type: Book Review

DOI: 10.3233/CH-1996-16113

Citation: Clinical Hemorheology and Microcirculation, vol. 16, no. 1, pp. 75-75, 1996

Article Type: Abstract

DOI: 10.3233/CH-1996-16114

Citation: Clinical Hemorheology and Microcirculation, vol. 16, no. 1, pp. 77-83, 1996

Article Type: Other

DOI: 10.3233/CH-1996-16115

Citation: Clinical Hemorheology and Microcirculation, vol. 16, no. 1, pp. 85-85, 1996