Acta physiologica Hungarica最新文献

Unlabelled: A β3 adrenoceptor agonist plays an important regulatory role in stimulation of thermogenesis and lipolysis and it appears to have anti-ulcer and spasmolytic effects. So the present aim was to examine the effect of BRL 37344 (a selective B3 adrenoceptor agonist) on reflux esophagitis.

Methods: Forty-eight rats were divided into twelve sham-operated with BRL 37344 and/or omeprazole with or without indomethacin. RE was induced in rats, then gastric acid output, pH, plasma nitric oxide (NO), esophageal PGE2, malondialdehyde (MDA) and reduced glutathione (GSH) were measured and the esophageal injury was assessed by macroscopic damage score.

Results: Pretreatment with BRL significantly increased plasma NO, GSH, decreased acid output, esophageal MDA and esophageal injury in comparison to pretreatment. In addition, there was a no significant increase in esophageal PGE2.

Conclusion: It can be concluded that BRL 37344 has an anti-oxidant protective effect in rats with RE.

Purpose: We investigated the impact of sex on the protective effect of postconditioning (POC), a series of brief ischemia-reperfusion (IR) cycles at the reperfusion onset, as a recently described novel approach to attenuate renal IR injury. In this study, the left renal pedicles of uni-nephrectomized male and female rats were clamped for 45 minutes followed by 24 hours of reperfusion as IR groups. Uni-nephrectomized, sham-operated male and female rats served as control groups. Ischemic postconditioning was performed using 4 cycles of 10 seconds of IR of renal pedicle at the end of the ischemia. Twenty-four hours later, BUN (blood urea nitrogen), plasma creatinine (Cr), and renal histological changes, as well as kidney levels of MDA (malondialdehyde) and SOD (superoxide dismutase) as oxidative stress markers were evaluated to detect the protective effect of POC against IR injury in rats.

Results: Induction of IR resulted in significant reduction in renal function, demonstrated by increase in plasma Cr and BUN, histological changes and oxidative stress in both genders. Application of POC afforded significant protection against these injuries in male rats, namely decreased levels of BUN and Cr, histological improvements and less oxidative damages. However, there were no significant differences in the above-mentioned parameters in female rats.

Conclusion: While POC is shown to be beneficial against renal IR injury in male rats, it did not show any protective effect in female rats.

The objective of the present study was to analyze the autonomic response of trained swimmers to traditional and reverse training periodization models. Seventeen swimmers were divided in two groups, performing a traditional periodization (TPG) or a reverse periodization (RPG) during a period of 10 weeks. Heart rate variability and 50 m swimming performance were analyzed before and after the training programs. After training, the TPG decreased the values of the high frequency band (HF), the number of differences between adjacent normal R-R intervals longer than 50 ms (NN50) and the percentage of differences between adjacent normal R-R intervals more than 50 ms (pNN50), and the RPG increased the values of HF and square root of the mean of the sum of the squared differences between adjacent normal R-R intervals (RMSSD). None of the groups improved significantly their performance in the 50-m test. The autonomic response of swimmers was different depending on the periodization performed, with the reverse periodization model leading to higher autonomic adaption. Complementary, the data suggests that autonomic adaptations were not critical for the 50-m swimming performance.

Purpose: The aim of the study was to determine whether creatine malate (CML) supplementation results in similar ergogenic effect in sprinters and long-distance runners. The other goal was to compare changes in body composition, physical performance and hormone levels after six-week training in athletes, divided into subgroups supplemented with creatine malate or taking placebo.

Results: Six-week supplementation combined with physical training induced different effects in athletes. Significantly higher increases in relative and absolute peak power and total work (p < 0.05) were found in sprinters compared to other groups. Except for growth hormone, post-exercise venous blood serum hormone levels exhibited no statistically significant differences in athletes. After CML loading period, a significant increase in growth hormone was found in the group of sprinters.

Conclusions: A significant ergogenic effect was found in sprinters, which was reflected by the increase in anaerobic exercise indices and morphological indices and elevated growth hormone level, after graded exercise testing. The significant increase in the distance covered during graded test was only observed in supplemented long-distance runners, whereas no significant changes in maximal oxygen uptake, relative peak power and relative total work were noticed. This could be caused by later anaerobic threshold appearance in exercise test to exhaustion.

Cycle training is widely performed as a major part of any exercise program seeking to improve aerobic capacity and cardiovascular health. However, the effect of cycle training on muscle size and strength gain still requires further insight, even though it is known that professional cyclists display larger muscle size compared to controls. Therefore, the purpose of this review is to discuss the effects of cycle training on muscle size and strength of the lower extremity and the possible mechanisms for increasing muscle size with cycle training. It is plausible that cycle training requires a longer period to significantly increase muscle size compared to typical resistance training due to a much slower hypertrophy rate. Cycle training induces muscle hypertrophy similarly between young and older age groups, while strength gain seems to favor older adults, which suggests that the probability for improving in muscle quality appears to be higher in older adults compared to young adults. For young adults, higher-intensity intermittent cycling may be required to achieve strength gains. It also appears that muscle hypertrophy induced by cycle training results from the positive changes in muscle protein net balance.

Characteristics of the athlete's heart have been investigated mostly in the left ventricle (LV); reports referring to the right ventricle (RV) have only appeared recently. The aim of the present study was to compare the training effects on RV and LV in elite male endurance athletes. To this end, echocardiography was conducted in 52 elite endurance athletes (A) and in 25 non-athletes (NA). Differences between A and NA in the morphology was more marked in the RV (body-size-matched (rel.)) long axis diastolic diameter (RVLADd): 63.4 ± 6.3 vs. 56.4 ± 6.3; rel. short axis diastolic diameter (RVSADd): 27.3 ± 3.6 vs. 23.6 ± 2.7 mm/m, RV diastolic area 28 ± 5.0 vs. 21.3 ± 4.3 cm2 in all cases, p < 0.001) than in the LV (rel. LVLADd: 63.8 mm/m ± 5.6 vs. 60.7 mm/m ± 6.6, p < 0.05, rel.LVSADd 37.8 ± 3.1 vs. 35.3 ± 2.4, no difference). In the athletes ratios of peak early to late diastolic filling velocity (2.07 ± 0.51 vs. 1.75 ± 0.36, p < 0.01), the TDI-determined E'/A' ratio in the septal (1.89 ± 0.55 vs. 1.62 ± 0.55, p < 0.05) and lateral (2.62 ± 0.72, vs. 2.18 ± 0.87, p < 0.001) walls were significantly higher than in NA only in the LV. Results indicate that in male endurance athletes morphologic adaptation is similar or slightly stronger in the RV than in the LV, functional adaptation seems to be stronger in the LV.

Unlabelled: Acute, severe hypovolemia is a medical emergency. Traditional vital sign parameters allow no optimal triage. High predictive power of finger plethysmography-based stroke volume (SV) and pulse pressure (PP) was recently suggested. To assess the performance of the PP and SV parameters, lower body negative pressure of -40 mmHg, than -60 mmHg - corresponding to moderate and severe central hypovolemia - was applied in 22 healthy males (age 35 ± 7 years). Slow breathing induced fluctuations in the above indices, characterized by stroke volume variability (SVV), and pulse pressure variability (PPV), were assessed. Responses in heart rate (HR) and shock index (SI) were also studied. Discriminative capacity of these parameters was characterized by the area under the ROC (receiver operating characteristic) curves (AUC).

Results: In comparison of baseline to severe central hypovolemia SV, PP, HR, and SI showed good discriminating capacity (AUC 99%, 88%, 87%, and 93%, respectively). The discriminating capacity of SVV and PPV was poor (77% and 70%, respectively). In comparison of moderate and severe hypovolemia, the discriminating capacity of the studied parameters was uniformly limited.

Conclusions: Plethysmography-based SV and PP parameters can be used to detect acute severe volume loss. Sensitive parameters discriminating moderate and severe central hypovolemia are still lacking.

Objective: In this study, we investigated the possible effect of Δ(9)-tetrahydrocannabinol (THC), a peroxisome proliferator-activated receptor gamma (PPARγ) agonist, on metabolic control and vascular complications of diabetes in streptozotocin/nicotinamide (STZ/NIC) induced type 2 diabetes mellitus.

Material and methods: Type 2 diabetes was induced with 65 mg/kg STZ, 15 minute later 85 mg/kg NIC was given intraperitoneally (i.p.) to rats. Three days after diabetes induction, THC (3 mg/kg/day, i.p.) was given for 7 days to diabetic rats. Body weight and plasma glucose levels of rats were measured in all groups before and at the end of 3 weeks after diabetes induction. Acetylcholine (Ach) and sodium nitroprusside (SNP) potency and maximum relaxant effects were calculated on aortic rings pre-contracted with noradrenaline (NA).

Results: At the end of 3 weeks, blood glucose levels of diabetic group significantly increased in comparison with the control group. Increased plasma glucose levels were significantly decreased by the treatment of THC. Ach induced relaxation was impaired whereas endothelium-independent relaxation to SNP was unaffected on isolated diabetic rat aorta. THC treatment enhanced Ach induced relaxation on diabetic rat aortas.

Discussion: These results suggested that THC improved endothelium-dependent relaxation in STZ/NIC induced diabetic rat aorta and that these effects were mediated at least in part, by control of hyperglycemia and enhanced endothelial nitric oxide bioavailability.