RESUMO
BACKGROUND: Severe bacterial infections initiate inadequate inflammation that leads to disseminated intravascular coagulation and death. OBJECTIVES: To evaluate the influence of bacterial infection on blood viscosity and red blood cells (RBCs) morphology, and the ability of Calotropis procera proteins (CpLP) to prevent the patho-hemorheology in infected animals. METHODS: Rheology of blood, atomic force microscopy measurements on specific blood elements and blood count were performed to examine changes in blood viscosity, RBCs morphology, platelets activation, and RBCs indices. FINDINGS: Infected mice hold their blood rheological behaviour as compared to that of the control group. However, they presented hyperactivated platelets, RBCs at different stages of eryptosis, and variation on RBCs indices. CpLP administration in healthy animals altered blood behaviour from pseudoplastic to Bingham-like fluid. Such effect disappeared over time and by inhibiting its proteases. No alterations were observed in RBCs morphology or platelets. Treatment of infected animals with CpLP prevented the changes in RBCs indices and morphology. MAIN CONCLUSIONS: The inflammatory process triggered by bacterial infection induced pathological changes in RBCs and platelets activation. Treatment of infected animals with CpLP prevented the emergence of RBCs abnormal morphology and this may have implications in the protective effect of CpLP, avoiding animal death.
Assuntos
Viscosidade Sanguínea/efeitos dos fármacos , Calotropis/química , Eritrócitos/microbiologia , Hemorreologia/efeitos dos fármacos , Proteínas de Plantas/farmacologia , Salmonella typhi , Febre Tifoide/sangue , Animais , Modelos Animais de Doenças , Contagem de Eritrócitos , Eritrócitos/efeitos dos fármacos , Masculino , Camundongos , Microscopia de Força Atômica , Proteínas de Plantas/isolamento & purificação , Índice de Gravidade de DoençaAssuntos
Anemia Falciforme/sangue , Anemia Falciforme/tratamento farmacológico , Viscosidade Sanguínea/efeitos dos fármacos , Deformação Eritrocítica/efeitos dos fármacos , Hidroxiureia/farmacologia , Hidroxiureia/uso terapêutico , Adulto , Antidrepanocíticos/farmacologia , Antidrepanocíticos/uso terapêutico , Feminino , Hematócrito , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
UNLABELLED: It was demonstrated that Ligaria cuneifolia (Lc) crude extract increased blood viscosity and decreased plasma cholesterol in rats. In the present study, we analyzed the Lc proanthocyanidin enriched fraction (PLc) to determine if it is capable of altering the hemorheological parameters while diminishing the plasma cholesterol. In vivo studies in adult male Wistar rats, randomized in three groups (nâ=â6 each one) were performed: 1. CONTROL: saline intraperitoneal (i.p.); 2. PLc 0.6âmg/100âg body weight (b.w.) i.p. and 3. PLc 3âmg/100âg b.w. i.p., every 24 hours during 3 days. IN VITRO STUDIES: with blood obtained by cardiac puncture, separated in aliquots and incubated with: 1. Saline solution (Control); 2. PLc 0.1âmg/mL, and 3. PLc 1.0âmg/mL, equivalent to doses in vivo experiments. The results demonstrated that in vivo PLc 0.6 and PLc 3 reduced plasma cholesterol (Cho) and LDL-Cho. Neither blood nor plasma viscosity was altered. Decrease of plasma cholesterol could be due to an increase of cholesterol and bile salts excretion leading to an increase of bile flow. In vitro experiments showed a direct interaction of PLc, at high concentration, with the erythrocyte membrane, inducing a switch from discocyte to stomatocyte. Only, PLc without hepatic metabolism produces hemorheological changes. Thus, PLc in vivo might be a pharmacological agent capable of decreasing plasma cholesterol.
Assuntos
Colesterol/sangue , Hemorreologia/efeitos dos fármacos , Loranthaceae/química , Extratos Vegetais/química , Folhas de Planta/química , Animais , Viscosidade Sanguínea/efeitos dos fármacos , Técnicas In Vitro , Masculino , Extratos Vegetais/farmacologia , Proantocianidinas , Ratos , Ratos WistarRESUMO
An evaluation of the rheological properties and the effects of Momordica. charantia L. (M. charantia) nanoparticles and polyethylene glycol (PEG) microspheres adsorbed with M. charantia nanoparticles on the blood of hyperglycemic patients is presented. Blood samples were collected according to glycemic status: normoglycemic (N = 56) and hyperglycemic (N = 26). General and hematological characteristics were determined. Blood rheological parameters were determined at room temperature and under a temperature scan. We determined the effects on whole blood viscosity of treatment with an extract of M. charantia, PEG, or PEG microspheres adsorbed with plant extract. The viscosity of the blood of hyperglycemic patients is greater than that of normoglycemic patients. Nanoparticles of M. charantia extracts lowered blood viscosity at equivalent rates in normo- and hyperglycemic individuals. PEG microspheres did not reduce blood viscosity in hyperglycemic individuals. However, PEG microspheres adsorbed with nanofraction extracts of M. charantia reduced blood viscosity. These data suggest that the effects of diabetes on the viscosity of the blood should be considered. The use of a nanoparticles extract of M. charantia and its adsorption on PEG microspheres may represent an alternative for the control and treatment of blood disorders in diabetic patients.
Assuntos
Diabetes Mellitus Tipo 2/sangue , Hemorreologia/efeitos dos fármacos , Momordica charantia/química , Extratos Vegetais/farmacologia , Adulto , Viscosidade Sanguínea/efeitos dos fármacos , Humanos , Hiperglicemia/sangue , Pessoa de Meia-Idade , TemperaturaAssuntos
Anemia Falciforme/sangue , Anemia Falciforme/tratamento farmacológico , Viscosidade Sanguínea/efeitos dos fármacos , Tetrazóis/administração & dosagem , Adulto , Cilostazol , Relação Dose-Resposta a Droga , Módulo de Elasticidade/efeitos dos fármacos , Feminino , Fibrinolíticos/administração & dosagem , Humanos , Masculino , Resultado do TratamentoRESUMO
Perfluorocarbon (PFC) emulsions used as artificial oxygen carriers lack colloid osmotic pressure (COP) and must be administered with colloid-based plasma expanders (PEs). Although PFC emulsions have been widely studied, there is limited information about PFC emulsion interaction with PEs and blood. Their interaction forms aggregates due to electrostatic and rheological phenomena, and change blood rheology and blood flow. This study analyzes the effects of the interaction between PFC emulsions with blood in the presence of clinically-used PEs. The rheological behavior of the mixtures was analyzed in vitro in parallel with in vivo analysis of blood flow in the microcirculation using intravital microscopy, when PEs were administered in a clinically relevant scenario. The interaction between the PFC emulsion and PE with blood produced PFC droplets and red blood cell (RBCs) aggregation and increased blood viscosity in a shear dependent fashion. The PFC droplets formed aggregates when mixed with PEs containing electrolytes, and the aggregation increased with the electrolyte concentration. Mixtures of PFC with PEs that produced PFC aggregates also induced RCBs aggregation when mixed with blood, increasing blood viscosity at low shear rates. The more viscous suspension at low shear rates produced a blunted blood flow velocity profile in vivo compared to nonaggregating mixtures of PFC and PEs. For the PEs evaluated, human serum albumin produced minimal to undetectable aggregation. PFC and PEs interaction with blood can affect sections of the microcirculation with low shear rates (e.g., arterioles, venules, and pulmonary circulation) when used in a clinical setting, because persistent aggregates could cause capillary occlusion, decreased perfusion, pulmonary emboli or focal ischemia.
Assuntos
Viscosidade Sanguínea/efeitos dos fármacos , Coloides/farmacologia , Fluorocarbonos/farmacologia , Substitutos do Plasma/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Coloides/química , Coloides/metabolismo , Interações Medicamentosas , Agregação Eritrocítica/efeitos dos fármacos , Fluorocarbonos/química , Fluorocarbonos/metabolismo , Oxigênio/metabolismo , Substitutos do Plasma/química , Substitutos do Plasma/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Calcium dobesilate is an angioprotective agent that has positive effects on hemorheological parameters. It is an antioxidant that increases endothelial-derived vasodilator substance secretion, there are none that analyze its effects during the postoperative period of patients undergoing myocardial revascularization. OBJECTIVE: We aimed to determine the effects of calcium dobesilate on hemorheological parameters, such as reduced glutathione and malondialdehyde in patients with ischemic heart disease undergoing myocardial revascularization in the postoperative period. METHODS: One hundred and thirty-four patients operated for coronary heart disease were included in this study. Hemorheological, oxidant and antioxidant parameters were measured two days after surgery and after a period of treatment with calcium dobesilate. Then, 500 mg of calcium dobesilate was given twice a day to one group of 68 patients for three months. The control group was composed of 66 patients who did not receive this medication. RESULTS: The increase in the erythrocyte deformability index was found to be significant compared with both the pretreatment values and with the 1st and 2nd values of the control group after calcium dobesilate administration, whereas there were no significant changes in blood viscosity, glutathione (GSH) or malondialdehyde (MDA) values after the calcium dobesilate administration. The same improvement in the CCS class was observed in patients regardless of they received the calcium dobesilate treatment. CONCLUSION: In the present investigation, the same improvement in the CCS class was observed in patients regardless of they received the calcium dobesilate treatment. Improvements with calcium dobesilate were statistically significant only in the increase in erythrocyte flexibility.
Assuntos
Dobesilato de Cálcio/uso terapêutico , Ponte de Artéria Coronária , Hemorreologia/efeitos dos fármacos , Hemostáticos/uso terapêutico , Idoso , Análise de Variância , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Viscosidade Sanguínea/efeitos dos fármacos , Dobesilato de Cálcio/farmacologia , Eritrócitos/efeitos dos fármacos , Feminino , Fibrinogênio , Glutationa/sangue , Glutationa/efeitos dos fármacos , Hemostáticos/farmacologia , Humanos , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Isquemia Miocárdica/cirurgia , Período Pós-Operatório , Estatísticas não ParamétricasRESUMO
BACKGROUND: Calcium dobesilate is an angioprotective agent that has positive effects on hemorheological parameters. It is an antioxidant that increases endothelial-derived vasodilator substance secretion, there are none that analyze its effects during the postoperative period of patients undergoing myocardial revascularization. OBJECTIVE: We aimed to determine the effects of calcium dobesilate on hemorheological parameters, such as reduced glutathione and malondialdehyde in patients with ischemic heart disease undergoing myocardial revascularization in the postoperative period. METHODS: One hundred and thirty-four patients operated for coronary heart disease were included in this study. Hemorheological, oxidant and antioxidant parameters were measured two days after surgery and after a period of treatment with calcium dobesilate. Then, 500 mg of calcium dobesilate was given twice a day to one group of 68 patients for three months. The control group was composed of 66 patients who did not receive this medication. RESULTS: The increase in the erythrocyte deformability index was found to be significant compared with both the pretreatment values and with the 1st and 2nd values of the control group after calcium dobesilate administration, whereas there were no significant changes in blood viscosity, glutathione (GSH) or malondialdehyde (MDA) values after the calcium dobesilate administration. The same improvement in the CCS class was observed in patients regardless of they received the calcium dobesilate treatment. CONCLUSION: In the present investigation, the same improvement in the CCS class was observed in patients regardless of they received the calcium dobesilate treatment. Improvements with calcium dobesilate were statistically significant only in the increase in erythrocyte flexibility.
ANTECEDENTES: O dobesilato de cálcio é um agente angioprotetor que tem efeitos positivos sobre os parâmetros hemorreológicos. É um antioxidante que aumenta a secreção endotelial derivada da substância vasodilatadora, não há nada que analisar os seus efeitos durante o período pósoperatório de pacientes submetidos a revascularização do miocárdio. OBJETIVO: Nosso objetivo foi determinar os efeitos de dobesilato de cálcio sobre os parâmetros hemorreológicos, tais como glutationa reduzida e malondialdeído em pacientes com doença cardíaca isquêmica submetidos a revascularização do miocárdio no pós-operatório. MÉTODOS: Cento e trinta e quatro pacientes operados por doença cardíaca coronária foram incluídos neste estudo. Parâmetros de oxidante, hemorreológicos e de antioxidantes foram medidos dois dias após a cirurgia e após um período de tratamento com o dobesilato de cálcio. Em seguida, 500 mg de dobesilato de cálcio foi administrado duas vezes por dia para um grupo de 68 pacientes durante três meses. O grupo controle foi composto por 66 pacientes que não receberam essa medicação. RESULTADOS: O aumento do índice de deformabilidade dos eritrócitos foi considerado significativo comparado com ambos os valores pré-tratamento e com os 1º e 2º valores do grupo controle após a administração dobesilato de cálcio, enquanto que não houve alterações significativas na viscosidade do sangue, na glutationa (GSH) ou malondialdeído (MDA) após a administração dobesilato de cálcio. A mesma melhoria na classe CCS foi observada em pacientes independentemente de terem recebido tratamento com dobesilato de cálcio. CONCLUSÃO: Na presente investigação, a mesma melhora na classe CCS foi observada em pacientes independentemente de terem recebido o tratamento com dobesilato de cálcio.
Assuntos
Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ponte de Artéria Coronária , Dobesilato de Cálcio/uso terapêutico , Hemorreologia/efeitos dos fármacos , Hemostáticos/uso terapêutico , Análise de Variância , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Viscosidade Sanguínea/efeitos dos fármacos , Dobesilato de Cálcio/farmacologia , Eritrócitos/efeitos dos fármacos , Fibrinogênio , Glutationa/sangue , Glutationa/efeitos dos fármacos , Hemostáticos/farmacologia , Malondialdeído/sangue , Isquemia Miocárdica/cirurgia , Período Pós-Operatório , Estatísticas não ParamétricasRESUMO
This study was designed to evaluate the effect of drag reducer polymers (DRP) on arteries from normotensive (Wistar) and spontaneously hypertensive rats (SHR). Polyethylene glycol (PEG 4000 at 5000 ppm) was perfused in the tail arterial bed with (E+) and without endothelium (E-) from male, adult Wistar (N = 14) and SHR (N = 13) animals under basal conditions (constant flow at 2.5 mL/min). In these preparations, flow-pressure curves (1.5 to 10 mL/min) were constructed before and 1 h after PEG 4000 perfusion. Afterwards, the tail arterial bed was fixed and the internal diameters of the arteries were then measured by microscopy and drag reduction was assessed based on the values of wall shear stress (WSS) by computational simulation. In Wistar and SHR groups, perfusion of PEG 4000 significantly reduced pulsatile pressure (Wistar/E+: 17.5 ± 2.8; SHR/E+: 16.3 ± 2.7 percent), WSS (Wistar/E+: 36; SHR/E+: 40 percent) and the flow-pressure response. The E- reduced the effects of PEG 4000 on arteries from both groups, suggesting that endothelial damage decreased the effect of PEG 4000 as a DRP. Moreover, the effects of PEG 4000 were more pronounced in the tail arterial bed from SHR compared to Wistar rats. In conclusion, these data demonstrated for the first time that PEG 4000 was more effective in reducing the pressure-flow response as well as WSS in the tail arterial bed of hypertensive than of normotensive rats and these effects were amplified by, but not dependent on, endothelial integrity. Thus, these results show an additional mechanism of action of this polymer besides its mechanical effect through the release and/or bioavailability of endothelial factors.
Assuntos
Animais , Masculino , Ratos , Hipertensão/fisiopatologia , Polietilenoglicóis/farmacologia , Cauda/irrigação sanguínea , Resistência Vascular/efeitos dos fármacos , Artérias/efeitos dos fármacos , Artérias/fisiologia , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Viscosidade Sanguínea/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Modelos Animais , Ratos Endogâmicos SHR , Ratos Wistar , Resistência Vascular/fisiologiaRESUMO
This study was designed to evaluate the effect of drag reducer polymers (DRP) on arteries from normotensive (Wistar) and spontaneously hypertensive rats (SHR). Polyethylene glycol (PEG 4000 at 5000 ppm) was perfused in the tail arterial bed with (E+) and without endothelium (E-) from male, adult Wistar (N = 14) and SHR (N = 13) animals under basal conditions (constant flow at 2.5 mL/min). In these preparations, flow-pressure curves (1.5 to 10 mL/min) were constructed before and 1 h after PEG 4000 perfusion. Afterwards, the tail arterial bed was fixed and the internal diameters of the arteries were then measured by microscopy and drag reduction was assessed based on the values of wall shear stress (WSS) by computational simulation. In Wistar and SHR groups, perfusion of PEG 4000 significantly reduced pulsatile pressure (Wistar/E+: 17.5 ± 2.8; SHR/E+: 16.3 ± 2.7%), WSS (Wistar/E+: 36; SHR/E+: 40%) and the flow-pressure response. The E- reduced the effects of PEG 4000 on arteries from both groups, suggesting that endothelial damage decreased the effect of PEG 4000 as a DRP. Moreover, the effects of PEG 4000 were more pronounced in the tail arterial bed from SHR compared to Wistar rats. In conclusion, these data demonstrated for the first time that PEG 4000 was more effective in reducing the pressure-flow response as well as WSS in the tail arterial bed of hypertensive than of normotensive rats and these effects were amplified by, but not dependent on, endothelial integrity. Thus, these results show an additional mechanism of action of this polymer besides its mechanical effect through the release and/or bioavailability of endothelial factors.
Assuntos
Hipertensão/fisiopatologia , Polietilenoglicóis/farmacologia , Cauda/irrigação sanguínea , Resistência Vascular/efeitos dos fármacos , Animais , Artérias/efeitos dos fármacos , Artérias/fisiologia , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Viscosidade Sanguínea/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Masculino , Modelos Animais , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Resistência Vascular/fisiologiaRESUMO
UNLABELLED: We tested the in vivo and the in vitro effects of both Ligaria cuneifolia catechin- and quercetin-enriched fractions on erythrocyte shape and deformability, and on plasma cholesterol level. For in vivo studies, adult male Wistar rats were randomized in three experimental groups which received intraperitoneally, once a day, 3 days: CONTROL: saline solution (C; n = 6); catechin from L. cuneifolia, 0.60 mg/100 g body weight (CLc; n = 6), or quercetin from L. cuneifolia, 2.3 mg/100 g body weight (QLc; n = 6). For in vitro studies, blood samples obtained from male Wistar rats were divided into three fractions, which were incubated with saline solution (C), catechin (CLc; n = 5) and quercetin (QLc; n = 5), in a concentration equivalent to 0.60 mg/100 g body weight, and 2.3 mg/100 g body weight, respectively. CLc significantly reduced the rigidity index due to a diminished mean concentration volume. QLc induced erythrocyte rigidization (less deformability), thus increasing blood viscosity. Neither of the two treatments produced any changes in plasmatic or biliary excretion of cholesterol. Opposite results were observed in rigidity index with CLc and QLc. In vitro studies showed an interaction of both CLc and QLc with the erythrocyte membrane, which induced changes in the erythrocyte shape from discocyte to stomatocyte.
Assuntos
Viscosidade Sanguínea/efeitos dos fármacos , Catequina/farmacologia , Colesterol/sangue , Loranthaceae/química , Extratos Vegetais/farmacologia , Quercetina/farmacologia , Animais , Catequina/química , Forma Celular/efeitos dos fármacos , Deformação Eritrocítica/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Hemorreologia/efeitos dos fármacos , Masculino , Quercetina/química , Ratos , Ratos WistarRESUMO
Decreasing blood viscosity has been proposed since the advent of hemodilution as a means for increasing perfusion in many pathological conditions, and increased plasma viscosity is associated with the presence of pathological conditions. However, experimental studies show that microvascular functions as represented by functional capillary density in conditions of significantly decreased viscosity is impaired, a problem corrected by increasing plasma and blood viscosity. Blood viscosity, primarily dependent on hematocrit (Hct) is a determinant of peripheral vascular resistance, and therefore blood pressure. In the healthy population Hct presents a variability, which is not reflected by the variability of blood pressure. This is due to a regulatory process at the level of the endothelium, whereby the increase of Hct (and therefore blood viscosity) leads to increased shear stress and the production of the vasodilator nitric oxide (NO), a finding supported by experimental studies showing that the acute increase of Hct lowers blood pressure. Studies that in the healthy population show that blood pressure and Hct have a weak positive correlation. However, when the effect of blood viscosity is factored out, blood pressure and Hct are negatively and significantly correlated, indicating that as blood viscosity increases, the circulation dilates. Conversely, lower Hct and blood viscosity conditions lead to a constricted circulation, associated with a condition of decreased NO bioavailability, and therefore a pro-inflammatory condition.
Assuntos
Viscosidade Sanguínea/fisiologia , Hemodiluição/métodos , Microcirculação/fisiologia , Viscosidade Sanguínea/efeitos dos fármacos , Fenômenos Fisiológicos Cardiovasculares , Hematócrito , Humanos , Hipertensão/sangue , Óxido Nítrico/sangue , Óxido Nítrico/metabolismo , Resistência Vascular/efeitos dos fármacosRESUMO
Arsenic (As) is a toxic semi-metal of wide distribution in nature. People living in regions where drinking water contains large quantities of arsenic, have an unusually high likelihood of developing blood-vessel diseases, but little is known about the mechanisms involved, i.e. the blood rheologic alterations that would contribute to the circulatory obstruction. Erythrocytes are the main target cells for arsenic compounds systemically absorbed and their cell membrane is the first place against the toxic. In this paper we have examined the in vitro effect of arsenic (As(V)) on the rheologic properties of human erythrocytes in relation with membrane fluidity and internal microviscosity. According to our present results, As(V) treatment produces oxidative degradation of membrane lipids and alteration of internal microviscosity. These red blood cells (RBCs) membrane and cytoplasmic structural damage consequently alters RBCs rheologic properties: an alteration of the RBCs discoid shape to stomatocytes, a diminution of erythrocyte deformability and an enhancement of osmotic fragility and cell aggregability. These effects impaired blood fluid behaviour that contribute to obstruct peripheral circulation and provides anemia, both clinic evidences typical of arsenic cronic intoxication.
Assuntos
Intoxicação por Arsênico/sangue , Eritrócitos/efeitos dos fármacos , Adulto , Viscosidade Sanguínea/efeitos dos fármacos , Agregação Eritrocítica/efeitos dos fármacos , Deformação Eritrocítica/efeitos dos fármacos , Membrana Eritrocítica/efeitos dos fármacos , Eritrócitos/metabolismo , Hemorreologia/efeitos dos fármacos , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Fluidez de Membrana/efeitos dos fármacos , Lipídeos de Membrana/metabolismo , Fragilidade Osmótica/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Doenças Vasculares/induzido quimicamenteRESUMO
Alpha macroglobulins (AM) are plasma proteins whose main function is to inactivate proteinases, protecting the tissues from the action of these enzymes. AM have influence on plasma viscosity (PV) and binds monofluorophosphate (MFP), which disturbs its homeostasis. The aim of this work was to evaluate whether the administration with MFP could modify blood viscosity. AM levels (micromol/l), PV (mPa.s), viscosity of red blood cells suspensions in NaCl 9 g/l (VES) and in autologue plasma (VEP) were measured in fifty-day old rats after a single dose of 80 micromol MFP or after 30 days of treatment with 80 micromol of MFP. Relative viscosity (RV) was calculated as the ratio VEP/PV. AM and PV increased significantly after 30 min of an oral dose of MFP. Controls (n=6), AM: 19.65+/-0.85, PV: 1.39+/-0.01, treated (n=6), AM: 22.88+/-0.75 (p<0.05), PV: 1.76+/-0.14 (p<0.05). After 30 days of treatment with MFP, AM and PV increased significantly. Controls (n=6), AM: 10.76+/-1.33, PV: 1.19+/-0.04, treated (n=6), AM: 17.66+/-1.27 (p<0.05), PV: 1.38+/-0.03 (p<0.05). The treatment with MFP modifies neither the VEP nor the RV. These results would indicate that AM and/or MFP did not interact with erythrocyte membrane and did not modify erythrocyte deformability.
Assuntos
Viscosidade Sanguínea/efeitos dos fármacos , Conservadores da Densidade Óssea/farmacologia , Fluoretos/farmacologia , Fosfatos/farmacologia , alfa-Macroglobulinas/efeitos dos fármacos , Administração Oral , Animais , Conservadores da Densidade Óssea/administração & dosagem , Deformação Eritrocítica/efeitos dos fármacos , Fluoretos/administração & dosagem , Masculino , Fosfatos/administração & dosagem , RatosRESUMO
The aim of this study was to test the hypothesis that vascular dysfunction in neonatal streptozotocin (n-STZ)-induced diabetic rats could be associated with alterations in blood pressure, hemodynamic profile, and levels of superoxide anion. Diabetes was induced by STZ injection (160 mg/kg, i.p.) in neonate (2-d-old) Wistar rats. Using intravital microscopy the changes in mesenteric arteriolar diameters to vasoconstrictor agent noradrenaline (NA) and the levels of superoxide anion, measured by hydroethidine microfluorography, were determined in anaesthetized control and n-STZ rats. Blood pressure (BP) was determined in anaesthetized and unanaesthetized animals. Heart rate, shear rate, and blood flow velocity were also assessed. n-STZ rats showed, after 8 weeks of STZ injection, increased BP (unanaesthetized animals), hyperactivity to NA, and increased superoxide anion levels. However, heart rate, arteriolar shear rate, and blood flow velocity were unchanged in n-STZ. In conclusion, the results of the current study describe a significant increase in blood pressure, hyperactivity to NA-mediated vasoconstriction, and increased superoxide levels measured by hydroethidine oxidation. Taken together, our findings demonstrate that the compromised ability of mesenteric microvessels to respond properly in n-STZ diabetic rats is associated with several vascular alterations.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Diabetes Mellitus Experimental/metabolismo , Frequência Cardíaca/efeitos dos fármacos , Norepinefrina/farmacologia , Fenantridinas/metabolismo , Superóxidos/metabolismo , Vasoconstritores/farmacologia , Animais , Disponibilidade Biológica , Viscosidade Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Experimental/fisiopatologia , Indicadores e Reagentes , Masculino , Microcirculação/efeitos dos fármacos , Oxirredução , Ratos , Ratos Wistar , Fluxo Sanguíneo Regional/efeitos dos fármacosRESUMO
This study sought to compare the effects of age and gender on blood viscosity and to appraise the effectiveness of Ginkgo biloba and Allium sativum extracts in reducing blood viscosity. Stage 1: Our sample consisted of 80 male volunteers (40 aged 18-60 and 40 aged 61 and over) and 80 females with the same age profile. Stage 2: We studied 60 male volunteers allocated in groups: placebo, G. biloba, and A. sativum. Stage 3: We studied 25 male volunteers and in the initial, intermediate, and final evaluations, the measures of blood viscosity were repeated. Volunteers were given a clinical evaluation and submitted to laboratory tests. G. biloba led to the highest reduction in blood viscosity compared with placebo and A. sativum. In relation to the use of the two substances, G. biloba and A. sativum, dry extract of G. biloba proved to be more effective in reducing blood viscosity.
Assuntos
Envelhecimento/sangue , Compostos Alílicos/farmacologia , Viscosidade Sanguínea/efeitos dos fármacos , Alho , Ginkgo biloba , Caracteres Sexuais , Sulfetos/farmacologia , Adolescente , Adulto , Idoso , Feminino , Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Extratos Vegetais/farmacologiaRESUMO
Ligaria cuneifolia (R et P) Tiegh. (Loranthaceae) (Lc) aqueous extract-treated rats by via intraperitoneal (i.p.) show increased blood viscosity and decreased plasma cholesterol (Chol) levels. In this work, we analize the effect of the vehicle polyvinylpyrrolidone (PVP) and that of the Methanolic Fraction of the extract of Lc (MFLc) on hemorrheological properties in vivo and in vitro and on biliary excretion. For in vivo conditions, adult male Wistar rats were divided in five experimental groups (n=5 each one) which were injected, every 24 hr during 3 days by via i.p., with: (1) saline solution (Control); (2) PVP 0.47 mg/100 g bw; (3) MFLc 0.95 mg/100 g bw plus PVP 0.47 mg/100 g bw; (4) PVP 12.5 mg/100 g bw; and (5) MFLc 23.0 mg/100 g bw plus PVP 12.5 mg/100 g bw. Intended for in vitro conditions, blood samples obtained by heart puncture were divided into three fractions, which were incubated with: saline solution (Control), PVP 12.5 mg%, and MFLc 25 mg% plus PVP 12.5 mg%. We demonstrated a direct effect of PVP alone and of MFLc "per se" on the erythrocyte membrane resulting in a cell shape change from dyscocyte to spherostomatocyte (MI more negative) as well as a decrease in erythrocyte deformability (increased RI). These changes induce an increase in blood viscosity. Decreased plasma Chol is a consequence of an increased bile salts biliary excretion.
Assuntos
Viscosidade Sanguínea/efeitos dos fármacos , Deformação Eritrocítica/efeitos dos fármacos , Membrana Eritrocítica/efeitos dos fármacos , Loranthaceae , Extratos Vegetais/farmacologia , Povidona/farmacologia , Animais , Bile/efeitos dos fármacos , Colesterol/sangue , Sistemas de Liberação de Medicamentos , Masculino , Folhas de Planta , Ratos , Ratos WistarRESUMO
Systemic scleroderma is an autoimmune disease, due to a connective tissue alteration characterized by extracellular matrix increase in the skin and internal organs. It is already known that the Raynaud's phenomenon and the microcapillary obliteration lead to ischemia and peripheral tissue injury. The ischemia-reperfusion phenomenon releases free radicals, that react with red blood cells (RBCs) membrane components originating lipid peroxidation and impairment of the ATP-Ca(++) pump, two possible mechanisms responsible of disease pathogenesis. Nifedipine is a Ca(++)-channel antagonist that has been used for a long time in Raynaud's phenomenon treatment. In the present study we were able to demonstrate that erythrocyte deformability and two other related variables such as membrane fluidity and osmotic fragility improve significantly with nifedipine therapy. It is likely that nifedipine inhibiting cytoplasmic calcium accumulation could restore some red blood cell membrane properties.
Assuntos
Viscosidade Sanguínea/efeitos dos fármacos , Bloqueadores dos Canais de Cálcio/farmacologia , Deformação Eritrocítica/efeitos dos fármacos , Nifedipino/farmacologia , Fragilidade Osmótica/efeitos dos fármacos , Escleroderma Sistêmico/tratamento farmacológico , Adulto , Feminino , Hemorreologia/efeitos dos fármacos , HumanosRESUMO
Baccharis trimera (Asteraceae) and Davilla rugosa (Dilleniaceae) are used popularly as tonics, aphrodisiacs and for stomach ailments, among other uses. Hydroalcohol extracts of the aerial parts of both plants were investigated with regard to their chemical constitution and their pharmacological activity in tests that evaluate adaptogen activity. Alkaloids, flavonoids, saponins, polyphenols/tannins and coumarins were identified in both extracts, while lignans were found only in the extract of Davilla rugosa. This extract presented also a marked antioxidant activity and exerted a moderate antiulcer effect in rats submitted to cold immobilization stress. It did not, however, inhibit the increase in the levels of ACTH and corticosterone induced by stress. Moreover, the Davilla rugosa did not improve the physical performance of mice submitted to forced exercise and the learning time of old rats in the T-maze, neither did it reduce the blood viscosity of the old animals. Conversely, the Baccharis trimera extract only presented a moderate antioxidant activity, without any positive effect on the other tests. These results point to the absence of an adaptogen activity of Baccharis trimera, with some effects that could be related to such an activity as regards the Davilla rugosa.
Assuntos
Antioxidantes/química , Baccharis/química , Dilleniaceae/química , Extratos Vegetais/química , Hormônio Adrenocorticotrópico/metabolismo , Alcaloides/química , Animais , Antioxidantes/farmacologia , Viscosidade Sanguínea/efeitos dos fármacos , Corticosterona/metabolismo , Cumarínicos/química , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Flavonoides/química , Lignanas/química , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Atividade Motora/efeitos dos fármacos , Fenóis/química , Componentes Aéreos da Planta/química , Extratos Vegetais/farmacologia , Polifenóis , Ratos , Ratos Wistar , Saponinas/química , Estresse Fisiológico/fisiopatologia , Taninos/química , Úlcera/fisiopatologia , Úlcera/prevenção & controleRESUMO
The aim of our work was to analyze the hemorheological parameters following partial hepatectomy in rats with chronic Al-intoxication (Al). Male Wistar rats were randomly assigned into four experimental groups (n=6 each one): Sham (rats subjected to simulated surgery); Al+Sham; Partial Hepatectomy (animals subjected to 65% liver resection) and Al+Partial Hepatectomy. Our results show that both Partial Hepatectomy and Al treatment produce a decrease of plasma cholesterol level, which showed a negative association with Rigidity Index increase (r(s)=-0.6475, p<0.05). The increase of Rigidity Index observed in Partial Hepatectomy, Al+Sham and Al+Partial Hepatectomy could be related to the increase of the proportion of non-discocytic erythrocytes, particularly stomatocytes, which determines a diminution of the Morphological Index. In the Altreated groups, greater changes in Rigidity Index and Morphological Index were observed. The relative viscosity of blood at a standard haematocrit of 40% was increased in Partial Hepatectomy, Al+Sham and Al+Partial Hepatectomy as compared to Sham, due to erythrocyte rigidity. On the other hand, we observed that the increase of plasma fibrinogen concentration correlates with augmentation of plasma viscosity (r(s)=0.689, p=0.004) for all the experimental groups studied. The results indicate that both administration of Al and Partial Hepatectomy induce microcytic hypocromic anaemia in the rats reflected by a significant decrease of haematocrit, mean corpuscular volume and mean corpuscular haemoglobin concentration. From these results, we conclude that in partially hepatectomized, Al-overloaded rats the decrease in erythrocyte deformability may be an important factor leading to the installation of anaemia.