The aim of this study was to an alyze the effect of indapamide and its combination with ACE inhi bitor (captopril) and antioxidant (ProvinolsTM) on both myocardial hypert rophy and fibrosis. Wistar rats were treated with L-NAME (40 mg/kg/day, L); L-NAME plus indapamide (1 mg/kg/day), or captopril (10 mg/kg/day), or ProvinolsTM (40 mg/kg/day), or combination of indapamide with captopril, and indapamide with Provinols TM for 7 weeks. Blood pressure (BP), LV hypertrophy an d fibrosis were determined. The content of collagens type I and III was evaluated morphometrically after picrosirius red staining. L-NAME treatment led to increased BP, LV hypertroph y, total fibrosis and relative content of collagens without th e change in collagen type I/III ratio. Indapamide and captopri l decreased BP, LV hypertrophy and the collagen ratio without affecting total fibrosis, while ProvinolsTM reduced BP, the collagen ratio and fibrosis without affecting LV hypertrophy. The combinations decreased all the parameters. Decrease of LV hypertrophy was achieved by drugs with the best reducing effect on BP, fibrosis reduction was reached by the antioxidant treatment with only partial effect on BP. Thus, the combination of an tihypertensive and antioxidant treatment may represent a powerful tool in preventing myocardial remodeling induced by hypertension., L. Hlavačková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The endocrine response is an important component of the physiological response to blood loss. There is some variability in reported levels of certain hormones during hemorrhage such as the stress hormone adrenocorticotrophic hormone (ACTH). Therefore, the effect of two an esthetic agents, ketamine and saffan, on ACTH and β-endorphin levels during hemorrhage was assessed in 12 minipigs. The animals were divided into two groups, group I saffan and group II ketamine (n=6). Pigs were subjected to a continuous fixed volume hemorrhage under one of the above anesthetics while spontaneously breathing. Blood pressure and heart rate responses were recorded together with β-endorphin and ACTH levels both before and at 10, 20, 30, 40 min after the onset of bleeding. ACTH levels were higher in the ketamine-anesthetized pigs and rose significantly faster with falling blood pressure than ACTH measured in pigs under saffan anesthesia. In contrast, the hemorrhage induced β-endorphin increase was not significantly different between the two anesthetic groups. These results indicate that choice of anesthetic agent is important when investigating the hormone response to hemorrhage and may account for the variable hormone levels in the published literature to date., T. Ruan-O´Hora, W. J. Hall, F. Markos., and Obsahuje seznam literatury
The aim of our study was to evaluate the influence of surgical removal of pheochromocytoma on the endocrine function of adipose tissue and subclinical inflammation as measured by circulating C-reactive protein (CRP) levels. Eighteen patients with newly diagnosed pheochromocytoma were included into study. Anthropometric measures, biochemical parameters, serum CRP, leptin, adiponectin and resistin levels were measured at the time of diagnosis and six months after surgical removal of pheochromocytoma. Surgical removal of pheochromocytoma significantly increased body weight, decreased both systolic and diastolic blood pressure, fasting blood glucose and glycated hemoglobin levels. Serum CRP levels were decreased by 50 % six months after surgical removal of pheochromocytoma (0.49±0.12 vs. 0.23±0.05 mg/l, p<0.05) despite a significant increase in body weight. Serum leptin, adiponectin and resistin levels were not affected by the surgery. We conclude that increased body weight in patients after surgical removal of pheochromocytoma is accompanied by an attenuation of subclinical inflammation probably due to catecholamine normalization. We failed to demonstrate an involvement of the changes in circulating leptin, adiponectin or resistin levels in this process., L. Bošanská ... [et al.]., and Obsahuje seznam literatury
Protective effect of quercetin, a natural antioxidant compound, on hypericin-induced cytotoxicity was studied in human promyelocytic leukemia cells (HL-60). Hypericin (10-5 mol.l-1) alone significantly decreased cell survival to 21 % that found in the controls, whereas in combination with quercetin (10-5 mol.l-1) this decrease was diminished to 46 %. Lower concentrations of quercetin had no protective effect. These findings indicate that oxygen radicals can play an important role in hypericin-induced phototoxic effects., A. Miroššay, H. Onderková, L. Mirossay, M. Šarišský, J. Mojžiš., and Obsahuje bibliografii
Diabetes mellitus is associated with a number of prothrombotic abnormalities, and correction of these abnormalities might translate into the reduction of cardiovascular risk. Glitazones improve endothelial function and reduce inflammation, but much less is known about their effect on thrombogenic factors. We have therefore studied the effect of rosiglitazone on leukocyte and soluble thrombogenic markers in patients with type 2 diabetes mellitus. Thirty-three subjects with type 2 diabetes and 32 normal controls were included; patients were examined at baseline and after 5 months of rosiglitazone treatment (4 mg/day). We measured leukocyte-platelet aggregates and leukocyte expression of either P-selectin glycoprotein ligand 1 (PSGL-1) or receptor for urokinase-type plasminogen activator (uPAR) using flow cytometry, as well as several circulating soluble thrombogenic markers by ELISA method. Leukocyte expression of uPAR and PSGL-1 was significantly higher in patients than in controls. Leukocyte-platelet aggregates and leukocyte expression of uPAR and PSGL-1 significantly decreased after rosiglitazone. There was also significant decrease in CRP and fibrinogen levels, but there was no effect of diabetes and/or rosiglitazone on other circulating molecules. In conclusions, we observed a substantial improvement in the expression of thrombogenic markers on leukocytes after rosiglitazone treatment, suggesting the novel antithrombotic effects of rosiglitazone., H. Svobodová ... [et al.]., and Obsahuje seznam literatury
A significant factor in the development of hypertension may be excessive vasoconstriction within the renal medulla. This study therefore investigated the role of superoxide dismutase (SOD) in the regulation of renal medullary and cortical blood perfusion (MBP and CBP, respectively) in both stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar rats. CBP and MBP were measured before and after intra-renal infusion of the SOD inhibitor, diethyldithio-carbamic acid (DETC). Under basal conditions, mean arterial pressure was significantly greater in SHRSP than Wistar rats, but both MBP and heart rate (HR) were significantly lower in SHRSP relative to Wistar rats (P<0.05, n=7 in both groups). Infusion of DETC (2 mg/kg/min) into the cortico-medullary border area of the kidney significantly decreased MBP in the SHRSPs (by 28±3 %, n=7, P<0.05), indicating a greater vasoconstriction within this vascular bed. However, DETC also significantly decreased MBP in Wistar rats to a similar extent (24±4 %, n=7, P<0.05). These results suggest that superoxide anions play a significant role in reducing renal vascular compliance within the renal medulla in both normotensive and hypertensive animals, although the responses are not greater in the hypertensive relative to the control animals., A. F. Ahmeda, M. G. Rae, L. M. Anweigi, M. F. Al Otaibi, A. A. Al-Masri, E. J. Johns., and Obsahuje bibliografii
Neuroprotective effects of estrogens and progesterone have been widely studied in various experimental models. The present study was designed to compare possible neuroprotective effects of 17alpha-estradiol, 17beta-estradiol, and progesterone on oxidative stress in rats subjecte d to global cerebral ischemia. Global cerebral ischemia was induced in ovariectomized female rats by four vessel occlusion for 10 min. Following 72 h of reperfusion, levels of malondialdehyde (MDA, oxidative stress marker), and reduced glutathione (GSH, major endogenous antioxidant) were assessed in hippocampus, striatum and cortex of rats treated with either 17alpha-estradiol, 17beta-estradiol, progesterone or estradiol + progesterone beforehand. Steroid administration ameliorated ischemia-induced decrease in GSH and increase in MDA levels. Our data offers additional evidence that estrogens and progesterone or combination of two exert a remarkable neuroprotective effect reducing oxidative stress., V. H. Ozacmak, H. Sayan., and Obsahuje seznam literatury
The present study investigated the effects of head cooling during endurance cycling on performance and the serotonergic neuroendocrine response to exercise in the heat. Subjects exercised at 75 % VO2max to volitional fatigue on a cycle ergometer at an ambient temperature of 29±1.0 °C, with a relative humidity of approximately 50 %. Head cooling resulted in a 51 % (p<0.01) improvement in exercise time to fatigue and Borg Scale ratings of perceived exertion were significantly lower throughout the exercise period with cooling (p<0.01). There were no indications of peripheral mechanisms of fatigue either with, or without, head cooling, indicating the importance of central mechanisms. Exercise in the heat caused the release of prolactin in response to the rise in rectal temperature. Head cooling largely abolished the prolactin response while having no effect on rectal temperature. Tympanic temperature and sinus skin temperature were reduced by head cooling and remained low throughout the exercise. It is suggested that there is a co-ordinated response to exercise involving thermoregulation, neuroendocrine secretion and behavioural adaptations that may originate in the hypothalamus or associated areas of the brain. Our results are consistent with the effects of head cooling being mediated by both direct cooling of the brain and modified cerebral artery blood flow, but an action of peripheral thermoreceptors cannot be excluded., L. Ansley, G. Marvin, A. Sharma, M. J. Kendall, D. A. Jones, M. W. Bridge., and Obsahuje bibliografii a bibliografické odkazy
Bupivacaine is a widely used long-acting local anaesthetic. In clinical practice, a mixture of bupivacaine and lidocaine is often used in order to combine the faster onset of sensory blockade of lidocaine with more profound and longer duration of blockade by bupivacaine. The aim of this study was to compare the cardiotoxicity of large doses of bupivacaine and mixture of bupivacaine with lidocaine in the isolated rat heart and to estimate whether or not the addition of lidocaine in clinically relevant concentration increases bupivacaine-induced toxicity. Experiments were performed on 21 adult male rats divided into three groups: B (6 μg/ml bupivacaine), BL (6 μg/ml bupivacaine and 12 μg/ml lidocaine) and L (12 μg/ml lidocaine). The experiment consisted of three 30 min periods: stabilisation, perfusion and washout. The isolated hearts were perfused according to Langendorff with Krebs-Henseleit solution at constant pressure (80 mmHg) and 37 °C (CaCl2 1.25 mM) and the heart rate (based on RR interval assessment), PQ and QRS intervals were measured. The present study shows that the mixture of tested anaesthetics - bupivacaine and lidocaine - impairs the intraventricular conduction parameters (QRS interval prolongation) to a lesser extent than bupivacaine itself, and that this effect is marked mainly at the beginning of perfusion., I. Křikava ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy