- Email: [email protected]
Measurement of plasma insulin levels in patients survived ischemic stroke
LIPOPROTEIN (HDL) MODULATE THE CONTRACTILE ACTIVITY OF LYMPH VESSELS Yu. Luchinin, G. Pak, S. Makarushko, R. Gareev, B. Nikitin Institute of Physiology MSNA. Almaty, PK
MEASUREMENT OF PLASMA INSULIN LEVELS IN PATIENTS SURVIVED ISCHEMIC STROKE B. N. Mankovsky*, S. M. Kuznezova**, E. A. Slivak** *Institute of Endocrinologv and **Institute of Gerontology, Kiev, Ukraine
The influence of LDL and HDL (10-8-10-2 mg albumine/ml) on spontaneous and induced contractile activity of bovine isolated vessels was studied. Lipoprotein were prepared from bovine blood plasma by ultracentrifugation: LDL (I .065), HDL (1.125). The experiments show that the increase in initial tonus and strengthening or initiating of phase construction were a typical reaction of lymphatics to LDL. As the LDL concentration increased, the latent period decreased and the parameters of contractile response increased. In case of a prolonged exposure or high LDL concentration no complete vessel relaxation occurred after LDL had been washed through, more over it could slowly increased. Under the previous exposition to LDL the lymphatic responses induced by noradrenaline (NA) and KC1 were significantly potentiated. The activation kept up till 30 min after the vessel was washed through. The HDL didn’t influence significantly on lymphatic contraction. Under the HDL>IO-5 mgiml some relaxation was observed. The amplitude and rate of development of contractile response induced by NA and KC1 were decreased after previous exposition to LDL. Thus, the LDL and HDL modulate the contractile activity of lymphatic in two opposite directions. The LDL activate and HDL depress the excitability and reactivity of lymphatic myocytes, that is the ratio of LDL/HDL determines its functional properties.
There are evidences that hyperinsulinemia and/or insulin resistance are strongly associated with increased risk of cardiovascular diseases. However, there is little information regarding insulin levels in patients with stroke. We investigated plasma insulin levels in homogeneous cohort of patients with ischemic stroke caused by occlusion of middle cerebral artery. We examined 10 patients (aged X6+6.85 yrs, mean+SD) who experienced stroke within 1-6 months before examination and 9 subjects without history of cerebrovascular attacks (aged 47.2k4.47 yrs). None of those patients had history of diabetes mellitus. Insulin levels in plasma were measured during standard oral glucose tolerance test using radioimmune assay. The comparison of results was made using Student’s paired test. The mean body mass index was similar in patients with stroke and controls 27.IkI.97 and 26.1k4.69 kg/m2, respectively, l~O.05. Patients in both groups were matched by their plasma cholesterol, LDL and HDL, glucose levels, prevalence of arterial hypertension. We found that insulin levels were not different between stroke patients and controls-at 0 min0.09t0.05 and 0.2+0.21; at 30 min - 0.41~0.22 and 0.42kO.21; at 60 min - 0.71t0.40 and 0.68+0.89; at I20min 0.22iO.19 and 0.22+0.15 nmol/L, respectively, p>O.O5. We conclude that plasma insulin levels are not elevated in patients with large vessel ischemic stroke.
FELICITOUS CELL MODEL TO STUDY THE INFLUENCE OF ATHEROGENIC FACTORS ON IN VITRO. CYTOKINE PRODUCTION E.Yu.Nikitinai, I.S.Freidlint, A.D.Denisenko*. Departments of Immunologyy’ and Biochemistry’, Institute of Experimental Medicine. St. Petersburg, Russia.
CHARACTERISTICS OF ERYTHROCYTE FLOW IN ELASTIC AND HARDENED MICROVESSELS N. Maeda, Y. Suzuki, J. Tanaka and N. Tateishi Department of Physiology School of Medicine, Ehime University, Ehime, Japan Microvascular bed of mesentery was isolated from rabbits. The marginal cell-free layer was compared in the elastic (E-) and 4% paraform- aldehyde-treated hardened (H-) microvessels with inner diameter of IO - 40 pm by perfusing human erythrocytes, and the thickness (TCL) was determined with an image analyser. The overall flow resistance (OFR) was determined by the perfusion pressure-flow volume relation. With lowering hematocrit, the TCL increased and the OFR decreased in both microvessels. The hematocrit-dependent change of TCL was greater in E-microvessels than in Hmicro- vessels, and the OFR was always greater in Hvascular bed. With decreasing erythrocyte deformability by crosslinking of spectrins, the reduction of TCL was observed at higher hematocrit in H-microvessels, and the OFR increased remarkably. By addition of dextran of MW=70,400, the drastic increment of TCL was observed in lower dextran concentration in H- microvessels than in in E-microvessels. In accordance with the increment of TCL, the increment of OFR was mitigated. In conclusion, the elasticity of microvessels is important for the reduction of OFR in vascular bed, which is modified by the TCL altering by the rheological properties of erythrocytes.
The aim of this research was to select the line of monocyte-like cells in order to study the atherogenesis. Murine macrophage-like P388Dt cells, human cells of monocytic line THP-I, monoblastoid line U937 and promyelocytic line HL-60 were investigated. L929 fibroblast bioassay and ELISA were used for tumour necrosis factor-cc (TNF) detection. P388Di, THP- I and HL-60 cells produced TNF in response to immune complexes (IC) containing native low-density lipoproteins (nLDL). But only HL-60 cells secreted TNF after stimulation by oxidized (ox)LDL-IC. These cells differentiated into macrophage-like cells under phorbol l2-myristate I3-acetate influence acquiring the ability to secrete TNF in response to nLDL or oxLDL. The myeloperoxidase activity of HL-60 cells permited to use the simple spectrophotometrical influence on adhesion test to study cytokine monocyte-endothelial cell interaction. Moreover we demonstrated that cocultivation of HL-60 cells with human umbilical vein endothelial cells (HUVEC) change cytokine response to nLDL and possibly to nLDL-IC. Thus, separate culture of HL-60 cells and their combination with HUVEC may be recommended as the felicitous cell model to investigate cytokine production, cell differentiation and cell interactions in atherosclerosis.
48
MEASUREMENT OF PLASMA INSULIN LEVELS IN PATIENTS SURVIVED ISCHEMIC STROKE B. N. Mankovsky*, S. M. Kuznezova**, E. A. Slivak** *Institute of Endocrinologv and **Institute of Gerontology, Kiev, Ukraine
The influence of LDL and HDL (10-8-10-2 mg albumine/ml) on spontaneous and induced contractile activity of bovine isolated vessels was studied. Lipoprotein were prepared from bovine blood plasma by ultracentrifugation: LDL (I .065), HDL (1.125). The experiments show that the increase in initial tonus and strengthening or initiating of phase construction were a typical reaction of lymphatics to LDL. As the LDL concentration increased, the latent period decreased and the parameters of contractile response increased. In case of a prolonged exposure or high LDL concentration no complete vessel relaxation occurred after LDL had been washed through, more over it could slowly increased. Under the previous exposition to LDL the lymphatic responses induced by noradrenaline (NA) and KC1 were significantly potentiated. The activation kept up till 30 min after the vessel was washed through. The HDL didn’t influence significantly on lymphatic contraction. Under the HDL>IO-5 mgiml some relaxation was observed. The amplitude and rate of development of contractile response induced by NA and KC1 were decreased after previous exposition to LDL. Thus, the LDL and HDL modulate the contractile activity of lymphatic in two opposite directions. The LDL activate and HDL depress the excitability and reactivity of lymphatic myocytes, that is the ratio of LDL/HDL determines its functional properties.
There are evidences that hyperinsulinemia and/or insulin resistance are strongly associated with increased risk of cardiovascular diseases. However, there is little information regarding insulin levels in patients with stroke. We investigated plasma insulin levels in homogeneous cohort of patients with ischemic stroke caused by occlusion of middle cerebral artery. We examined 10 patients (aged X6+6.85 yrs, mean+SD) who experienced stroke within 1-6 months before examination and 9 subjects without history of cerebrovascular attacks (aged 47.2k4.47 yrs). None of those patients had history of diabetes mellitus. Insulin levels in plasma were measured during standard oral glucose tolerance test using radioimmune assay. The comparison of results was made using Student’s paired test. The mean body mass index was similar in patients with stroke and controls 27.IkI.97 and 26.1k4.69 kg/m2, respectively, l~O.05. Patients in both groups were matched by their plasma cholesterol, LDL and HDL, glucose levels, prevalence of arterial hypertension. We found that insulin levels were not different between stroke patients and controls-at 0 min0.09t0.05 and 0.2+0.21; at 30 min - 0.41~0.22 and 0.42kO.21; at 60 min - 0.71t0.40 and 0.68+0.89; at I20min 0.22iO.19 and 0.22+0.15 nmol/L, respectively, p>O.O5. We conclude that plasma insulin levels are not elevated in patients with large vessel ischemic stroke.
FELICITOUS CELL MODEL TO STUDY THE INFLUENCE OF ATHEROGENIC FACTORS ON IN VITRO. CYTOKINE PRODUCTION E.Yu.Nikitinai, I.S.Freidlint, A.D.Denisenko*. Departments of Immunologyy’ and Biochemistry’, Institute of Experimental Medicine. St. Petersburg, Russia.
CHARACTERISTICS OF ERYTHROCYTE FLOW IN ELASTIC AND HARDENED MICROVESSELS N. Maeda, Y. Suzuki, J. Tanaka and N. Tateishi Department of Physiology School of Medicine, Ehime University, Ehime, Japan Microvascular bed of mesentery was isolated from rabbits. The marginal cell-free layer was compared in the elastic (E-) and 4% paraform- aldehyde-treated hardened (H-) microvessels with inner diameter of IO - 40 pm by perfusing human erythrocytes, and the thickness (TCL) was determined with an image analyser. The overall flow resistance (OFR) was determined by the perfusion pressure-flow volume relation. With lowering hematocrit, the TCL increased and the OFR decreased in both microvessels. The hematocrit-dependent change of TCL was greater in E-microvessels than in Hmicro- vessels, and the OFR was always greater in Hvascular bed. With decreasing erythrocyte deformability by crosslinking of spectrins, the reduction of TCL was observed at higher hematocrit in H-microvessels, and the OFR increased remarkably. By addition of dextran of MW=70,400, the drastic increment of TCL was observed in lower dextran concentration in H- microvessels than in in E-microvessels. In accordance with the increment of TCL, the increment of OFR was mitigated. In conclusion, the elasticity of microvessels is important for the reduction of OFR in vascular bed, which is modified by the TCL altering by the rheological properties of erythrocytes.
The aim of this research was to select the line of monocyte-like cells in order to study the atherogenesis. Murine macrophage-like P388Dt cells, human cells of monocytic line THP-I, monoblastoid line U937 and promyelocytic line HL-60 were investigated. L929 fibroblast bioassay and ELISA were used for tumour necrosis factor-cc (TNF) detection. P388Di, THP- I and HL-60 cells produced TNF in response to immune complexes (IC) containing native low-density lipoproteins (nLDL). But only HL-60 cells secreted TNF after stimulation by oxidized (ox)LDL-IC. These cells differentiated into macrophage-like cells under phorbol l2-myristate I3-acetate influence acquiring the ability to secrete TNF in response to nLDL or oxLDL. The myeloperoxidase activity of HL-60 cells permited to use the simple spectrophotometrical influence on adhesion test to study cytokine monocyte-endothelial cell interaction. Moreover we demonstrated that cocultivation of HL-60 cells with human umbilical vein endothelial cells (HUVEC) change cytokine response to nLDL and possibly to nLDL-IC. Thus, separate culture of HL-60 cells and their combination with HUVEC may be recommended as the felicitous cell model to investigate cytokine production, cell differentiation and cell interactions in atherosclerosis.
48