The effect of blocking the first and rate-limiting step in renin-angiotensin cascade on the renal function in ischemia reperfusion injury has not been previously in vestigated. We investigated the effect of aliskiren, the first approved direct oral renin inhibitor, on the alterations in renal functional parameters in this condition. Wistar rats underwent left renal ischemia for 40 min. Group-1 received normal saline whereas Group-2 received aliskiren (30 mg/kg/day) by gavage for 6 days commencing one day before IRI. The hemodynamic an d tubular functions and gene expression of neutrophil gelatinase-associated lipocalin (NGAL) and plasminogen activating inhibitor (PAI-1) in the right and left kidneys were measured five days following the IRI. Comparing Group-1 and Group-2, the left renal blood flow was significantly higher in Group-2 (1.28±0.36 vs. 0.39±0.05, P=0.007). Left kidney glomerular filtration rate was also higher in Group-2 but did not reach statistical signif icance (0.18±0.05 vs. 0.10±0.02, P=0.07). The left renal FE Na was significantly lower in Group-2 (29.9±6.4 vs. 49.7±7.8, P=0.03). Aliskiren also caused a significant decrease in the gene expression of both NGAL and PAI-1 in the left ischemic kidney. In conclusions, the administration of aliskiren before and after IRI appears to have ameliorated the IRI effect on the total renal artery blood flow, and fractional excretion of sodium and gene expression of both NGAL and PAI-1 indicating a renoprotective effects in IRI., F. T. Hammad, S. Al-Salam, L. Lubbad., and Obsahuje bibliografii a bibliografické odkazy
Melatonin has been shown to play a role in antioxidative defence. We therefore studied its effect on oxidative damage to the rat cerebral cortex evoked by painful stimulation and immobilization-induced stress. Moreover, the effect of melatonin on chronic pain perception was examined. Rats were injected with either a high dose of melatonin (100 mg/kg i.p.) or a vehicle for five days and were subjected to painful stimulation or immobilization stress 30 min after the treatment. To determine the degree of oxidative stress, the levels of free radicals, thiobarbituric acid reactive substances (TBARS) as indicators of lipid peroxidation and glutathione peroxidase (GSHPx) were estimated in somatosensory cortex. Pain perception was measured by the tail-flick and plantar test. Melatonin reduced the level of TBARS previously increased by painful stimulation. Melatonin also exhibited a slight analgesic effect in those animals exposed to painful stimulation but its role in free radical scavenging did not contribute to this effect., I. Pekárková, S. Parara, V. Holeček, P. Stopka, L. Trefil, J. Racek, R. Rokyta., and Obsahuje bibliografii
The aim was to compare methods of body fat measurement in different BMI groups. An additional aim was to discuss differences reflecting the structural and functional changes of fat tissue. The study group included 130 adult Caucasian women stratified by body mass index (BMI): 18-24.99 (n=30), 25-29.99 (n=26), 30-34.99 (n=33), 35-39.99 (n=30), and BMI ≥ 40 (n=11). Bioelectrical impedance was performed using Tanita TBF 410 GS, Bodystat 1500, and Omron BF 300. A caliper type Best was also applied. Correspondence of four methods with DEXA was assessed using the Bland-Altman and ANOVA analyses. Measurements by BIA were not si gnificantly different from DEXA up to BMI of 30, but DEXA significantly overestimated in the higher BMI subgroup by all three methods. Caliper measurement significantly underestimated DEXA in all BMI subgroups. BIA methods overestimated DEXA for the obese subjects. Tanita did statistically the best. The Caliper test appeared less preferable than the BIA methods, especially in the higher BMI subgroup. DEXA and Caliper measurements seem to be the best estimate of structural (anatomical) fat quantity. We hypothesize that BIA methods could also measure some other physiopathological conditions like inflammation, hydration or cell infiltration of fat., R: Větrovská, Z. Vilikus, J. Klaschka, Z. Stránská, Š. Svačina, Š. Svobodová, M. Matoulek., and Obsahuje bibliografii
Microgravity or simulated microgravity induces acute and chronic cardiovascular responses, whose mechanism is pivotal for understanding of physiological adaptation and pathophysiological consequences. We investigated hemodynamic responses of conscious Wistar rats to 45º head-down tilt (HDT) for 7 days. Arterial blood pressure (BP) was recorded by telemetry. Heart rate (HR), spectral properties and the spontaneous baroreflex sensitivity (sBRS) were calculated. Head-up tilt (HUT) was applied for 2 h before and after HDT to assess the degree of any possible cardiovascular deconditio ning. Horizontal control BP and HR were 112.5±2.8 mmHg and 344.7±10 bpm, respectively. HDT elicited an elevation in BP and HR by 8.3 % and 8.8 %, respectively, in less than 1 h. These elevations in BP and HR were maintained for 2 and 3 days, respectively, and then normalized. Heart rate variability was unchanged, while sBRS was permanently reduced from the beginning of HDT (1.01±0.08 vs. 0.74±0.05 ms/mmHg). HUT tests before and after HDT resulted in BP elevations (6.9 vs. 11.6 %) and sBRS reduction (0.44 vs. 0.37 ms/mmHg), respectively. The pressor response during the post-HDT HUT test was accompanied by tachycardia (13.7 %). In conclusion, chronic HDT does not lead to symptoms of cardiovascular deconditioning. However the depressed sBRS and tachycardic response seen during the post-HDT HUT test may indicate disturbances in cardiovascular control., G. Raffai ... [et al.]., and Obsahuje seznam literatury
We investigated the potential role of magnesium (Mg) dysbalance in the pathogenesis of insulin resistance (IR) in patients with mildly-to-moderately decreased renal function (creatinine: 142.8±11.0 mmol/l). The data were compared to those of 8 age- and sex-matched healthy controls (CTRL). The standard oral glucose tolerance test (oGTT) was performed in 61 patients. Twenty-two patients were classified as IR according to their values on fasting and after-load immunoreactive insulin concentrations. Serum and total erythrocyte Mg (tErMg) (atomic absorption spectro-photometry) and free erythrocyte Mg (fErMg) concentrations (31P NMR spectroscopy) were determined prior to and two hours after the glucose load. Ten out of 39 insulin-sensitive (IS) patients, but only one out of 22 insulin-resistant (IR) patients, had a low basal fErMg concentration (<162.2 mmol/l, c2, p<0.01). IR patients had higher serum Mg, total erythrocyte Mg and bound erythrocyte Mg (bErMg) concentrations (both before and after glucose load) when compared with the IS group. Both groups responded to the glucose load with a significant decrease in serum Mg concentration (within the normal range), while the IR group also exhibited a decline in tErMg and bErMg. The mean sum of insulin needed to metabolize the same glucose load correlated positively with tErMg (r=0.545, p<0.01) and bErMg (r=0.560, p<0.01) in the IR patients. It is concluded that, at an early stage of renal dysfunction, IR is not associated with the decline in free erythrocyte Mg concentration, but the magnesium handling in red blood cells is altered., K. Šebeková, K. Štefíková, D. Polakovičová, V. Spustová, R. Dzúrik., and Obsahuje bibliografii
Primary hyperaldosteronism (PH) is frequently considered to be a secondary form of diabetes mellitus (DM). In our previous study we attempted to evaluate the prevalence of DM among patients with PH compared to control subjects with essential hypertension (EH). We have noted a relatively high prevalence of DM and impaired glucose tolerance in PH, but the differences between the PH and EH groups did not reach statistical significance. We performed this study to assess whether the effective treatment of PH (surgical and conservative) would improve the glucose tolerance. We have studied 24 patients with PH of the following two subtypes: aldosterone-producing adenoma (APA) treated with adrenalectomy and idiopathic hyperaldosteronism (IHA) treated with spironolactone. No significant changes of glucose levels were found in the 60th and 120th min of the oral glucose tolerance test (OGTT) in the APA group. On the other hand, fasting glucose levels were decreased significantly after adrenalectomy. Plasma glucose levels were significantly increased in the 60th min, but no differences were found in fasting values and in the 120th min in the IHA group. There was a significantly higher incidence of impaired glucose tolerance (36 % before, 45 % after treatment) and DM (9 %, 18 %) in the IHA group compared to the APA group (8 %, 32 %; DM 0 %, 0 %). In conclusion, the treatment of PH does not improve glucose tolerance. Mild worsening of glucose tolerance after treatment could be explained by an increase of the body mass index. These data, in accordance with our previous study, do not support the idea that PH is a secondary form of diabetes mellitus., B. Štrauch, J. Widimsky Jr., G. Šindelka, J. Škrha., and Obsahuje bibliografii
Anticonvulsant action of vigabatrin (300, 600, 900 and/or 1200 mg/kg i.p.), an inhibitor of GABA-transaminase, was studied in a model of motor sezures elicited by pentylenetetrazol. Five age groups of rats (7, 12, 18, 25 and 90 days old) received a s.c. injection of pentylenetetrazol 4, 6 and/or 24 hours after vigabatrin administration. The incidence of minimal, predominantly clonic seizures was not changed in any age group, but their latencies were prolonged in 18- and 25-day-old rats. Generalized tonic-clonic seizures were influenced in a more complex manner. Incidence of these seizures was decreased in 7-day-old rat pups 24 hours after vigabatrin administration. Higher doses of vigabatrin exhibited a similar effect in adult rats at all intervals studied. Specific suppression or at least restriction of the tonic phase was observed in all groups of immature rats, the effect was more marked 24 hours after vigabatrin than at shorter intervals. The anticonvulsant action of vigabatrin, which could be demonstrated mainly against generalized tonic-clonic seizures, varies markedly during development., R. Haugvicová, H. Kubová, P. Mareš., and Obsahuje bibliografii