Calcium dobesilate may improve hemorheology in patients undergoing coronary artery bypass grafting / Dobesilato de cálcio pode melhorar hemorreologia em pacientes submetidos à cirurgia de revascularização miocárdica

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.

Drag reduction by polyethylene glycol in the tail arterial bed of normotensive and hypertensive rats

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.

Effects of chemically-induced stress on blood viscosity of rabbits.

Disease-induced stress in a living system needs its characterization before quantification. We address this problem by studying the flow behaviour of blood of rabbits. The flow behaviour of rabbit blood, both normal and streptozotocin-induced diabetic was observed by plotting viscosity levels against known shear stress. The curves obtained from normal animals showed a curvilinear relationship between eta and tau, whereas the curves obtained from the blood of the induced diabetic animals showed a 'thixotropic' nature i.e. viscosity varies inversely with shear stress. The results obtained were (a) increased viscosity associated with increasing doses, (b) the lower the shear stress, higher was the viscosity and (c) significant variation of viscosity levels between normal and induced-diabetic rabbits observed by increased stress. The possible interpretation of the results in the light of rheological properties of blood is discussed.

Efectos del aceite de hígado de bacalao como fuente de ácidos grasos n-3 sobre las lipoproteínas y la viscosidad sanguínea en pacientes con hiperlipoproteinemias primarias / Effects of cod liver oil as a source of fatty acids n-3 on lipoproteins and blood viscosity in patients with primary hyperlipoproteinemia

Las dietas ricas en AG-n-3 se consideran antiaterogénicas. El aceite de hígado de bacalao (AHB) contine 19 g/dl de AG-n-3 y 850 mg de colesterol, por lo cual estudiamos su efecto sobre las lipoproteínas plasmáticas y la viscosidad sanguínea en pacientes con hiperlipoproteinemias primas (clasificados según la OMS) y/o B-VLDL elevada, que se definió por la relación col-VLDL/TG > 0,35, beta ancha en el lipidograma electroforético y test de precipitación con heparina-MgCl2-NaCl. El grupo A, compuesto por pacientes de tipos IIa (n = 4), IIb (4), IV (2) y B-VLDL elevada, 1) recibió 50 ml/día de AHB. El grupo B, compuesto por pacientes por tipo IIa (4), IIb (9), IV (4), B-VLDL elevada (5) y V (2) recibió 25 ml/día. Un mes antes del tratameitno y durante éste dieta de los pacientes era baja en hidratos de carbono refinados, con menos de 300 mg de colesterol al día y supresión de etanol. en las muestras basales y a los 21 días de tratamiento se midieron TG, Col-en VLDL, LDL, HDL2 y HDL3, apo A1 y apo B, viscosidades sanguíneas, sérica y plasmática. En el grupo A disminuyeron TG (p < 0,05), pero col-VLDL/TG aumentó (p < 0,01) y apreció B-VLDL en 6 de 11 pacientes. En el grupo B, bajaron TG y col-VLDL (p < 0,02 y p < 0,05, respectivamente) pero los 5 pacientes con B-VLDL basal no mejoraron. Apo A1 aumentó (p < 0,05). El col-LDL no disminuyó en níngún grupo. El AHB no tiene efecto en pacientes con B-VLDL basal o hiperlipémicos de tipos IIa o IIb, en cambio los pacientes de tipo IV mejoraran. El AHB disminuye la viscosidad sanguínea (p < 0,05) pero no afecta la plasmática