Influence of physical effort on aortic stiffness in young male athletes.

OBJECTIVE: The progression of cardiovascular disease is blunted by regular exercise training as a common non-pharmacological treatment. Recent findings have confirmed that central aortic pressure is more strongly related to cardiovascular events than brachial blood pressure. The aim of the study was to evaluate the influence of a single bout of significant physical effort on central aortic pressure and pulse wave velocity in young male athletes. PATIENTS AND METHODS: The study group consisted of 16 healthy male athletes undergoing regular endurance training. The subjects of the study (21.6 ± 2.85 years of age) underwent a submaximal exercise test consisting of cycling for 30 minutes. Aortic pulse wave velocity (PWV) and derivatives (augmentation index set to 75 heart beats, AIx75; pulse pressure amplification, PPA), ejection duration (ED), subendocardial viability ratio (SEVR) and central blood pressure were examined before and after the exercise test Blood pressure and pulse waveform were evaluated in the supine position after a 15-minute rest by means of the oscillometric method the oscillometric method. RESULTS: Comparing the rest condition to the period immediately following the exercise test, athletes showed lower central than peripheral systolic blood pressure both before (129 ± 11 mmHg and 112 ± 8 mmHg, respectively, p < 0.001) and after (130 ± 10 mmHg to 112 ± 8 mmHg, respectively, p < 0.001) the test. They also showed a decrease of ED from 339.7 ± 44.4 ms to 326.9 ± 41.4 ms (p < 0.02) and an increase of PPA from 136.2 ± 5.4% to 140.3 ± 5.0% (p < 0.02), whereas PWV, AIx75 and SEVR changed insignificantly. CONCLUSIONS: We confirm that PPA is sensitive to an instant change in aortic elasticity. Furthermore, the hemodynamic response to a single physical effort composed of shorter ejection time and increased relative elasticity of the aorta prevents impairment of oxygen supply to the heart musculature.

Antioxidant status of turkey breast meat and blood after feeding a diet enriched with histidine.

The objective of this study was to investigate the effects of 1) spray dried blood cells rich in histidine and 2) pure histidine added to feed on the antioxidant status and concentration of carnosine related components in the blood and breast meat of female turkeys. The experiment was performed on 168 Big7 turkey females randomly assigned to 3 dietary treatments: control; control with the addition of 0.18% L-histidine (His); and control with the addition of spray dried blood cells (SDBC). Birds were raised for 103 d on a floor with sawdust litter, with drinking water and feed ad libitum. The antioxidant status of blood plasma and breast muscle was analyzed by ferric reducing ability (FRAP) and by 2,2-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging ability. The activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) was analyzed in the blood and breast meat, with the content of carnosine and anserine quantified by HPLC. Proximate analysis as well as amino acid profiling were carried out for the feed and breast muscles. Growth performance parameters also were calculated. Histidine supplementation of the turkey diet resulted in increased DPPH radical scavenging capacity in the breast muscles and blood, but did not result in higher histidine dipeptide concentrations. The enzymatic antioxidant system of turkey blood was affected by the diet with SDBC. In the plasma, the SDBC addition increased both SOD and GPx activity, and decreased GPx activity in the erythrocytes. Feeding turkeys with an SDBC containing diet increased BW and the content of isoleucine and valine in breast muscles.

Influence of different histidine sources and zinc supplementation of broiler diets on dipeptide content and antioxidant status of blood and meat.

1. The objective of this study was to investigate how a diet containing spray-dried blood cells (SDBC) (4%) with or without zinc (Zn) would affect the concentration of two histidine heterodipeptides and the antioxidant status of broiler blood and breast muscles. 2. The study was carried out on 920 male Flex chickens randomly assigned to 4 dietary treatments: I - control, II - diet I with SDBC, III - diet I with SDBC and supplemented with Zn and IV - diet I supplemented with L-histidine. Birds were raised on floor littered with wood shavings, given free access to water and fed ad libitum. Performance indices were measured on d 1, 21 and 42. 3. The activity of antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase was analysed in plasma, erythrocytes and muscle tissue. The total antioxidant capacity of plasma and breast muscles was measured by 2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, as well as by ferric reducing antioxidant power (FRAP). Carnosine/anserine content of meat and plasma were determined using HPLC. Diets and breast muscles were analysed for amino acid profile and selected microelement content. 4. Histidine supplementation of the diet increased glutathione peroxidase activity in plasma and superoxide dismutase activity in erythrocytes. Moreover, the addition of SDBC or pure histidine in the diet increased histidine dipeptide content and activated enzymatic and non-enzymatic antioxidant systems in chicken blood and muscles. However, it led to lower growth performance indices. 5. The enrichment of broiler diets with Zn increased the antioxidant potential and the activity of superoxide dismutase in plasma, which was independent of the histidine dipeptide concentration. Zn supplementation combined with SDBC in a broiler diet led to the increase of superoxide dismutase and glutathione peroxidase activity, but it did not affect the radical-scavenging or ferric iron reduction abilities of muscles.

Antioxidation status and histidine dipeptides content in broiler blood and muscles depending on protein sources in feed.

One-day-old chickens were fed mixtures containing different raw materials (fish by-products meal, porcine blood cells meal, blood meal, wheat gluten, fodder yeast), as a source of histidine and ß-alanine - components of carnosine. Control birds were administered a feed mixture, in which soy bean meal was the main protein source. The bodyweight, feed consumption and conversion, antioxidant characteristics and histidine dipeptides content in blood and muscles, and also amino acid composition of chicken meat on day 34 post-hatch were recorded. The best (p < 0.05) performance and feed conversion were observed in chickens fed mixture containing porcine blood cells meal. In blood plasma of control chickens, a significantly (p < 0.01) higher ability to scavenge DPPH radicals was found. However, the highest catalase activity in erythrocytes was determined in chickens fed mixtures with blood by-products. Insignificant differences in both carnosine and anserine levels in plasma between treatments were noted. Breast muscles from control birds were characterized by lower activity of glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) (p < 0.05; p < 0.01), than those from chickens fed blood by-products. Improved ability to reduce ferric ions (FRAP) (p < 0.01) and carnosine content in meat from chickens fed blood cell meal were recorded. No direct relations between amino acids content in feed mixtures and in meat were observed.

Effect of unilateral nephrectomy on the pharmacokinetics of amikacin in humans.

As unilateral nephrectomy is not a rare surgical procedure, it gives rise to the question whether drugs predominantly eliminated through the urinary tract can be handled effectively by the remaining kidney. Amikacin is predominantly excreted via glomerular filtration with only a small fraction undergoing tubular reabsorption, and can be used as a model drug of glomerular elimination. The study was carried out in 28 subjects, 10 one month and 10 one year after unilateral nephrectomy, as well as in 8 healthy subjects. The pharmacokinetics of amikacin was investigated after a 1-h infusion of 5 mg kg(-1) amikacin. Blood samples were collected for 24 h after the end of infusion. Pharmacokinetic parameters of amikacin were calculated using a one-compartment open model for intravenous administration. Amikacin concentrations were significantly elevated in nephrectomized patients as compared with control subjects, both 1 month and 1 year after the surgery, and were similar at these two time-points following unilateral nephrectomy. Pharmacokinetic parameters of amikacin in patients subjected to unilateral nephrectomy were significantly different from those observed in the control subjects. As compared with the controls, an increase in AUC (area under the serum concentration-time curve) by 81% (P < 0.001) and 63% (P < 0.01) 1 month and 1 year after nephrectomy was observed, respectively. The lambda(z) (elimination rate constant) was reduced by 39% (P < 0.001) after 1 month and by 38% (P < 0.001) 1 year after the operation and t 1/2 was prolonged by 70% (P < 0.001) and by 43% (P < 0.01) at the respective time-points following unilateral nephrectomy. CLT (total body clearance of the drug from plasma) and CL(BW) (clearance per kg body weight) were both significantly decreased in unilaterally nephrectomized subjects in comparison with the controls. CLT and CL(BW) were reduced by 53% (P < 0.001) and 42% (P < 0.01) 1 month after nephrectomy, and by 45% (P<0.001) and 42% (P<0.01) 1 year after the surgery, respectively. No significant differences among studied groups were found in C0 (initial serum drug concentration) and Vd (apparent volume of distribution). The results suggest that unilateral nephrectomy impairs elimination of amikacin, and possibly other drugs predominantly eliminated via glomerular filtration.

Serum alpha 2-antiplasmin activity following rapid decompression from a hyperbaric environment in rabbit.

Changes in serum alpha 2-antyplasmin (alpha 2-AP) in rabbits exposed to hyperbaric environment (6 ATA, 40 min.) and 5-minute decompression (1 ATA/min) were estimated. 10 male New Zealand white rabbits consisted the studied group, and 10 the control group. Blood samples were collected in rabbits from the femoral artery: once before placing the rabbit in the hyperbaric chamber, and three times after opening the chamber: just after decompression, at 10 and 20 minutes after collecting the second sample. Serum alpha 2-AP activity was measured using chromogenic substrates. Rapid decompression in rabbits exposed to hyperbaric environment at 6 ATA caused decrease in serum alpha 2-AP activity. Significant decrease in serum alpha 2-AP activity was observed at 20 min. after decompression. Serum alpha 2-AP activity can be applied in diagnostics of DCS.

[Spirometric investigation and spiro-ergometric test in evaluation of exercise tolerance in patients suffering from aluminosis and silicosis]. / Badanie spirometryczne a test spiroergometryczny w ocenie zdolnosci wysilkowej u chorych na pylice krzemowo-glinowa.

The main purpose of our research was to estimate the ventilation and physical efficiency in 6 patients suffering from aluminosis and silicosis. Chest X-ray examinations, statical spirometric investigations and spiroergometric tests (TSE) were performed. Oxygen levels achieved in this group were equal or even higher than medium values achieved by healthy people. Ability to physical effort can be estimated only using TSE.