RESUMO
It has been suggested that the increase in concentration of blood lipid peroxides may be a risk factor for atherosclerosis. Our research was conducted to study the effect of cholesterol feeding on lipid peroxides, ceruloplasmin, HDL-cholesterol, serum unesterified fatty acids, and copper concentration in serum and aortic tissue in rats. In the animals fed a cholesterol-supplemented diet, the mean values of serum lipid peroxide, ceruloplasmin, serum copper, and unesterified fatty acids were increased significantly (p < 0.01) as compared to the control group. At the same time, HDL-cholesterol concentration was significantly decreased in rats fed a diet enriched with cholesterol (p < 0.01) compared to the control group. A significant decrease of copper concentration in aorta was also observed in these animals versus controls. Correlations between ceruloplasmin and lipid peroxides as well as copper were statistically significant in these animals. At the same time, antioxidant activity in blood was two times higher as compared to controls. Results of this study provide the support for applying these determinations in atherosclerosis monitoring.
Assuntos
Aorta/metabolismo , Arteriosclerose/metabolismo , Ceruloplasmina/metabolismo , Cobre/sangue , Animais , Arteriosclerose/induzido quimicamente , Colesterol na Dieta/administração & dosagem , HDL-Colesterol/sangue , Cobre/metabolismo , Ácidos Graxos/sangue , Radicais Livres , Peróxidos Lipídicos/sangue , Masculino , Ratos , Ratos WistarRESUMO
Wistar rats were kept for 2 and 4 weeks in conditions of near null magnetic field. The total serum proteins, lipids and glucides, as well as the leucocyte and neutrophil counts showed no significant changes against controls kept in natural magnetic field conditions. A significant monocytosis, a decrease in the circulating phagocyte count and in the phagocytic activity was noticed in null magnetic field. These results suggest that the natural magnetic field significantly influences health both on the ground and possibly in cosmic conditions.
Assuntos
Leucócitos/efeitos da radiação , Magnetismo , Animais , Proteínas Sanguíneas/análise , Carboidratos/sangue , Contagem de Leucócitos/efeitos da radiação , Lipídeos/sangue , Neutrófilos/efeitos da radiação , Fagocitose/efeitos da radiação , Ratos , Ratos Wistar , Voo EspacialRESUMO
Some characteristics of Epo binding to the red cell membranes were investigated in a system in which the hormone was added to a suspension of cells in a mixture of normal serum phosphate buffered saline (1:7 (V/V)), testing the unbound Epo. Epo binding shows a gradual decrease during the maturation of red cells (0.15 U/ml packed erythrocytes, 0.285 U/ml reticulocytes and 0.375 U/ml erythroblasts from a total of 1.4 U/ml). The binding is also time- and pH-dependent. The amounts of Epo bound within 60 min are independent of temperature, but after 120 min a dissociation of the hormone-receptor complex occurred at 23 and 37 degrees; at 4 degrees C the binding continue, although at a very low rate. RBC membranes bound the hormone at pH 7.8-8 and release it at pH 6.5. The "in vivo" stimulation of beta receptors with isoproterenol increases the erythropoietic response caused by Epo, suggesting a possible relation with the adenylcyclase system.
Assuntos
Membrana Eritrocítica/metabolismo , Eritropoetina/sangue , Anemia/sangue , Animais , Eritropoetina/isolamento & purificação , Eritropoetina/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Isoproterenol/farmacologia , Camundongos , Ligação Proteica , Coelhos , Receptores Adrenérgicos beta/efeitos dos fármacos , Reticulócitos/metabolismo , Temperatura , Fatores de TempoAssuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Úlcera Duodenal/tratamento farmacológico , Suco Gástrico/efeitos dos fármacos , Antagonistas Adrenérgicos beta/farmacologia , Adulto , Determinação da Acidez Gástrica , Suco Gástrico/análise , Hexoses/análise , Humanos , Ácidos Neuramínicos/análise , Pepsina A/análise , Propranolol/farmacologia , Ácido Vanilmandélico/análiseRESUMO
The determinations carried out on 12 divers during the immersion into the sea to a depth between 7 and 29 m, as well as on controls in immersions at 4 m revealed a significant prolongation of the visual reaction time and a marked tachycardia. The changes were more marked at great depths and if exercise was superimposed over hyperbaric stress. A rise in the urinary excretion of 17-HOCS and vanillylmandelic acid and an impairment of the manual dexterity were also found during immersions. The results stress the importance of divers' monitoring during their underwater activity and the necessity of improving their physical training.
Assuntos
Pressão Atmosférica , Mergulho , Tempo de Reação , Taquicardia/etiologia , 17-Hidroxicorticosteroides/urina , Adulto , Eletrocardiografia , Humanos , Masculino , Destreza Motora , Esforço Físico , TelemetriaRESUMO
Thirteen healthy males were repeatedly studied during the exposure to a moderate hyperbaric environment of 4--6, 7 and 9 ATA, in a hyperbaric chamber and partly during immersion in sea water (3.5--4 ATA). The maximal duration of the exposure was 35 min and that of decompression 90 min. As compared to the dynamics of the change found in controls, under hyperbaric conditions a significant prolongation of the visual reaction time (especially during sea dives), and an impairment of the mental performance in an arithemetical calculation test were found. There occurs an increase of the excretion in urine of cortisol, epinephrine and vanillylmandelic acid, especially after immersion in sea.
