Clinical Hemorheology and Microcirculation - Volume 17, issue 5

Authors: Boisseau, Michel R.

Article Type: Other

Citation: Clinical Hemorheology and Microcirculation, vol. 17, no. 5, pp. 349-349, 1997

Authors: Bouskela, E. | Cyrino, F.Z.G.A. | Bougaret, S.

Article Type: Research Article

Abstract: Cyclo 3 Fort is used in the treatment of chronic venous insufficiency. In this study, the effects of Cyclo 3 Fort, 2, 10 and 50 mg/kg, were studied in cheek pouch preparations from diabetic hamsters. The mean arteriolar diameter in animals receiving Cyclo 3 Fort, 10 and 50 mg/kg, was significantly greater than in control animals (p<0.05 ), and the mean venule diameter was significantly lower in animals receiving the 50 mg/kg dose than in the control group. This suggests that Cyclo 3 Fort, 50 mg/kg/day, has a venotonic effect in diabetic animals. The venoarteriolar reflex was studied by …measuring the internal diameter of arterioles during venular occlusion. The reflex was impaired in animals treated with either placebo or 2 mg/kg, but this was reversed by treatment with Cyclo 3 Fort, 10 and 50 mg/kg. Show more

Keywords: Hamster cheek pouch, microvessel diameter, venoarteriolar reflex, diabetic hamster, Cyclo 3 Fort

Citation: Clinical Hemorheology and Microcirculation, vol. 17, no. 5, pp. 351-356, 1997

Authors: Khodabandehlou, T. | Zhao, H. | Vimeux, M. | Le Dévéhat, C.

Article Type: Research Article

Abstract: The skin microvascular autoregulatory capacity was investigated in healthy volunteers and diabetic patients without or with vascular complications. To assess this capacity, skin blood flux (SBF) of different areas was examined during different procedures of venous stasis, standing position, and passive lowering of the leg. SBF was evaluated by laser doppler fluxmetry. There was, in healthy control subjects, the same degree of vasoconstriction, i.e., the same reduction in SBF irrespective of the site of measurement and the procedure used. In diabetic patients, the vasoconstriction elicited in the finger pulp by venous stasis was normal. By contrast, the vasoconstrictor responses …to standing or lowering of the leg were impaired. In fact there was, in some patients, an increased SBF instead of a decreased one during standing or lowering of the leg. Impaired vasoconstrictor responses to standing or lowering of the leg was observed even in patients without complications; the impairment, however, was more marked in patients with complications. Thus, the inability of the diabetic skin microvasculature to respond normally to postural changes may be an important factor initiating the development of foot complications. The contribution of local and central reflexes to microvascular autoregulation in diabetic patients and control subjects was also discussed. Show more

Keywords: Microvascular autoregulation, laser doppler fluxmetry, venous stasis, standing position, lowering of the leg, diabetes mellitus

Citation: Clinical Hemorheology and Microcirculation, vol. 17, no. 5, pp. 357-362, 1997

Authors: Le Dévéhat, C. | Khodabandehlou, T. | Zhao, H. | Vimeux, M.

Article Type: Research Article

Abstract: The relationship between either an acute or a chronic hyperglycemia and functional microcirculatory disturbances was studied in insulin‐dependent diabetic (IDD) patients in comparison to healthy volunteers. Acute hyperglycemia, provoked in 10 IDD patients, was accompanied by an increase in laser doppler skin blood flux while transcutaneous oxygen pressure (TcPO_2 ) decreased. These changes, accompanied by that in the concentration of moving blood cells indicate that acute hyperglycemia results in a vasodilation in favour of non‐nutritive microvascular shunts. The effect of chronic hyperglycemia was studied in 36 IDD patients who had a duration of diabetes of less than 5 years …and had no clinical signs of micro‐ and macroangiopathy. In these patients, erythrocyte aggregation, plasma viscosity and fibrinogen concentration were increased and transcutaneous oxygen pressure reduced, compared with the levels seen in healthy subjects. More marked impairments were observed in patients with poor glycemic control. This suggests that chronic hyperglycemia involves functional disturbances which will contribute to the development of the vascular complications of diabetes. In 34 patients with poorly controlled diabetes who received intensive insulin therapy for 36 months, these changes were reversed in patients in whom good glycemic control was achieved within 2 months, but not in those in whom glycemic control remained poor. It is concluded that disturbances in blood flow and TcPO_2 occur early in diabetes, and are consequences of poor glycemic control. These disturbances can be reversed or normalized if glycemic control is improved by intensive treatment. Show more

Keywords: Acute hyperglycemia, chronic hyperglycemia, intensive insulin therapy, blood flux, transcutaneous oxygen pressure, erythrocyte aggregation

Citation: Clinical Hemorheology and Microcirculation, vol. 17, no. 5, pp. 363-370, 1997

Authors: Pangratis, N.

Article Type: Research Article

Abstract: The procedure for studying skin capillaries using vital capillary microscopy is described. Capillary changes take place in patients with reduced arterial circulation, and these are examined in the lower and upper (nailfold) extremity. Dynamic capillaroscopy is a technique for measuring capillary blood cell velocity. The calculation can be performed simply using a computerized system and serves as a useful diagnostic tool in the study of nailfold capillaries. These investigations are applicable in the context of increased prevalence of macro‐ and microangiopathy associated with diabetes mellitus.

Citation: Clinical Hemorheology and Microcirculation, vol. 17, no. 5, pp. 371-383, 1997

Authors: Svensjö, E. | Bouskela, E. | Cyrino, F.Z.G.A. | Bougaret, S.

Article Type: Research Article

Abstract: Ruscus aculeatus extract (the active principle of Cyclo 3 Fort) is used to increase venous tone in patients with venous disease. In these experiments, the effects of oral Cyclo 3 Fort on capillary permeability were studied in hamsters with moderate diabetes induced by two intraperitoneal injections of streptozotocin (40 mg/kg). Hamsters were treated with a placebo or Cyclo 3 Fort, 2, 10 or 50 mg/kg/day, for 4 weeks starting 3 days after induction of diabetes. Intravital microscopy of cheek pouch preparations was performed using fluorescein‐labelled dextran (FITC‐dextran) as a marker for plasma exudation (leak formation). Plasma levels of glucose were …measured prior to experiments. Following preparation for intravital microscopy, each cheek pouch was subjected to two applications of histamine, 5\times10^{-6} M for 5 min at 30‐minute intervals. Plasma exudation (number of leaks/cm^2 ) was significantly reduced in animals receiving Cyclo 3 Fort at doses of 10 mg/kg or above. The mean number of leaks was 258\pm17 in the placebo group, compared with 253\pm12 , 125\pm7 (p<0.01 ) and 99\pm7 (p<0.01 ) in animals receiving Cyclo 3 Fort, 2, 10 or 50 mg/kg, respectively. Blood glucose levels did not differ between groups. Thus, oral Cyclo 3 Fort inhibited histamine‐induced plasma exudation in hamsters with mild diabetes without affecting the glycaemia. Show more

Keywords: Hamster cheek pouch postcapillary venules, histamine, Ruscus extract, Cyclo 3 Fort, plasma leakage inhibition

Citation: Clinical Hemorheology and Microcirculation, vol. 17, no. 5, pp. 385-388, 1997

Authors: Valensi, P. | Cohen‐Boulakia, F. | Attali, J.R. | Behar, A.

Article Type: Research Article

Abstract: Microangiopathic disorders, characterized by capillary vasodilation and increases in capillary blood flow and permeability, are common in diabetes and can occur before the development of microangiopathic complications. In a study of 163 diabetic patients, capillary permeability, measured by albumin retention (AR), was increased in 39% of patients. AR was increased more frequently in women than in men, and in patients without microangiopathic complications than in patients with complications. Increased AR was significantly associated with insulin‐dependent diabetes in male patients. Lymphatic function was abnormal in 72% of patients; this abnormality was often present before AR increased. The pathophysiology of microangiopathy is …complex and involves metabolic, haemodynamic, neurological and hormonal factors. Improved control of glycaemia and blood pressure can reduce capillary permeability. In addition, studies with a flavonoid fraction and n‐3 polyunsaturated fatty acids suggest that these agents may also be beneficial. Show more

Keywords: Diabetic microangiopathy, capillary permeability, lymphatic function, albumin retention

Citation: Clinical Hemorheology and Microcirculation, vol. 17, no. 5, pp. 389-394, 1997