Repeated Supramaximal Exercise-Induced Oxidative Stress: Effect of ß-Alanine Plus Creatine Supplementation.

BACKGROUND: Carnosine is a dipeptide formed from the ß-alanine and histidine amino acids and found in mainly in the brain and muscle, especially fast twitch muscle. Carnosine and creatine has an antioxidant effect and carnosine accounts for about 10% of the muscle's ability to buffer the H(+) ions produced by exercise. OBJECTIVES: The aim of the study was to investigate the effects of beta alanine and/or creatine supplementation on oxidant and antioxidant status during repeated Wingate tests (WTs). PATIENTS AND METHODS: Forty four sedentary males participated in the study. Participants performed three 30s WTs with 2 minutes rest between exercise bouts. After the first exercise session, the subjects were assigned to one of four groups: Placebo, Creatine, Beta-alanine and Beta-alanine plus creatine. Participants ingested twice per day for 22 consecutive days, then four times per day for the following 6 days. After the supplementation period the second exercise session was applied. Blood samples were taken before and immediately after the each exercise session for the analysis of oxidative stress and antioxidant markers. RESULTS: Malondialdehyde levels and superoxide dismutase activities were affected by neither supplementation nor exercise. During the pre-supplementation session, protein carbonyl reduced and oxidized glutathione (GSH and GSSG) levels increased immediately after the exercise. However, during the post-supplementation session GSH and GSSG levels increased in beta-alanine and beta-alanine plus creatine groups immediately after the exercise compared to pre-exercise. In addition, during the post-supplementation session total antioxidant capacity increased in beta-alanine group immediately after the exercise. CONCLUSIONS: Beta-alanine supplementation has limited antioxidant effect during the repeated WTs.

Effects of Coenzyme Q10 Supplementation on Exercise Performance and Markers of Oxidative Stress in Hemodialysis Patients: A Double-Blind Placebo-Controlled Crossover Trial.

Coenzyme Q10 (CoQ10) supplementation has been shown to decrease oxidative stress in a number of clinical settings. However, there are mixed results regarding the role of CoQ10 supplementation on exercise performance. Chronic kidney disease is recognized as an inflammatory state, and hemodialysis patients have low level of exercise performance. We aimed to evaluate the effect of CoQ10 supplementation on oxidative stress markers and exercise performance measures. This was a prospective, double-blind, placebo-controlled, crossover study in which all patients received placebo and oral CoQ10 200 mg/d. Participants underwent 6-minute walking test and cycle ergometer. Blood samples were drawn to determine malondialdehyde, oxidized low-density lipoprotein, superoxide dismutase, and glutathione peroxidase. Walking distance in 6-minute walking test and estimated maximal oxygen consumption (VO2max) were recorded. Twenty-eight patients were randomized, but 23 patients completed the study protocol. Serum CoQ10 level significantly increased with supplementation compared with basal values (P < 0.05). Neither walking distance nor estimated VO2max was different between the placebo and CoQ10 groups (P > 0.05). Serum malondialdehyde levels significantly increased in both groups compared with baseline values just after the exercise (P < 0.05). There was no difference in markers of oxidative stress and antioxidant system between placebo and CoQ10 supplementation with exercise (P > 0.05). The results of this study showed no significant effect of CoQ10 supplementation on exercise performance measures and oxidative system markers compared with placebo in maintenance hemodialysis patients.

Effects of grape seed extract on oxidative stress and antioxidant defense markers in streptozotocin-induced diabetic rats.

BACKGROUND/AIM: To evaluate the effects of grape seed extract (GSE) supplementation on oxidative stress and antioxidant markers in streptozotocin (STZ)-induced diabetic rats. MATERIALS AND METHODS: Thirty-six male rats were divided into the following four groups: control, GSE-supplemented control, diabetic, and GSE-supplemented diabetic. Beginning on day 7 after STZ injection, the rats were administered GSE (100 mg kg(-1) day(-1) in drinking water for 6 weeks. At the end of week 6, rats were sacrificed by cardiac puncture. Plasma nitric oxide (NO) levels and xanthine oxidase (XO), adenosine deaminase (ADA), and glutathione peroxidase (GPx) activities were analyzed. RESULTS: Both XO and ADA activities increased and NO levels decreased in diabetic rats (P < 0.05). GSE supplementation normalized all of these changes. Antioxidant enzyme activities decreased in diabetic rats compared to the controls (P < 0.05). GSE supplementation increased antioxidant enzyme activities in both diabetic and healthy rats (P < 0.05). CONCLUSION: These findings suggest that 6 weeks of oral GSE supplementation may prevent oxidative stress and improve antioxidant status in diabetic rats.

Lack of association between leptin levels and leptin gene polymorphism in obese women.

The aim of the present study was to evaluate the relationship between oligopolymorphism in the 25th codon of leptin gene and obesity. Eighty-seven obese women and 75 healthy women were constituted obese and control groups. Body fat percent, fat mass and lean body mass were determined by bioimpedance meter and leptin levels were determined. The presence of 25th codon oligopolymorphism in the leptin gene was done by PCR-RFLP technique. Mean leptin levels were 38.5±22.0 ng/ml, and 147.9±44.8 ng/ml in the control and obese groups, respectively. The correlations of serum leptin level to body fat percentage and fat mass in the control group were significant. The correlations in the obese group were not significant. This data implies that the difference of leptin levels between control and obese groups are more likely to be associated with alterations in the leptin gene other than 25th codon or alterations in the leptin receptor gene.

Coenzyme Q10 supplementation and diastolic heart functions in hemodialysis patients: a randomized double-blind placebo-controlled trial.

Coenzyme Q10 (CoQ10) supplementation has been shown to improve diastolic heart function in various patient cohorts. Systolic and diastolic dysfunctions are common in patients with end-stage renal disease. Favorable effects of CoQ10 on cardiac functions are yet to be seen in hemodialysis patients. We aimed to evaluate effect of CoQ10 supplementation on diastolic function in a cohort of maintenance hemodialysis patients. This was a prospective, double-blind, placebo-controlled, crossover study in which all patients received placebo and oral CoQ10 200 mg/d during the 8 weeks in each phase, with a 4-week washout period. Participants underwent conventional and tissue Doppler echocardiography before and after each study phase. Parameters characterizing left ventricle diastolic function and other standard echocardiographic measurements were recorded. Twenty-eight patients were randomized, but 22 patients completed study protocol. Intraventricular septum (IVS) thickness and left ventricle mass were significantly decreased in CoQ10 group (P = 0.03 and P = 0.01, respectively). Myocardial peak systolic and early diastolic velocities derived from IVS were significantly increased (P = 0.048 and P = 0.04, respectively). Isovolumetric relaxation time and E/Em ratio calculated for IVS also significantly reduced in CoQ10 group (p = 0.02 and p = 0.04, respectively). There was no significant difference in any of the studied echocardiographic parameters in placebo group. The results of this study showed that CoQ10 supplementation did not significantly improved diastolic heart functions compared with placebo in maintenance hemodialysis patients.

Effects of grape seed polyphenols on oxidative damage in liver tissue of acutely and chronically exercised rats.

The objective of the present study was to investigate the effects of grape seed extract (GSE) supplementation on oxidative stress and antioxidant defense markers in liver tissue of acutely and chronically exercised rats. Rats were randomly assigned to six groups: Control (C), Control Chronic Exercise (CE), Control Acute Exercise (AE), GSE-supplemented Control (GC), GSE-supplemented Chronic Exercise(GCE) and GSE-supplemented Acute Exercise (GAE). Rats in the chronic exercise groups were subjected to a six-week treadmill running and in the acute exercise groups performed an exhaustive running. Rats in the GSE supplemented groups received GSE (100 mg.kg(-1) .day(-1) ) in drinking water for 6 weeks. Liver tissues of the rats were taken for the analysis of malondialdehyde (MDA), nitric oxide (NO) levels and total antioxidant activity (AOA) and xanthine oxidase (XO) activities. MDA levels decreased with GSE supplementation in control groups but increased in acute and chronic exercise groups compared to their non-supplemented control. NO levels increased with GSE supplementation. XO activities were higher in AE group compared to the CE group. AOA decreased with GSE supplementation. In conclusion, while acute exercise triggers oxidative stress, chronic exercise has protective role against oxidative stress. GSE has a limited antioxidant effect on exercise-induced oxidative stress in liver tissue.

Oxidative stress and anti-oxidant status in diabetic rat liver: effect of plant polyphenols.

Increased evidence in role of oxidative stress and grape seed extract (GSE) in diabetes and its complication led us to investigate the changes of oxidative stress and anti-oxidant defence in liver tissue of diabetic rats and possible effects of GSE. Diabetes was induced by a single intraperitoneal injection of streptozotocin. Seven days after STZ injection four groups were formed: Control, GSE-supplemented control, diabetic and GSE-supplemented diabetic and GSE was given for 6 weeks. Malondialdehyde levels and xanthine oxidase activities were not different among the groups. However, nitric oxide (NO) levels were higher in diabetic and GSE supplemented groups compared with non-diabetic and non-supplemented groups, respectively. Total anti-oxidant activity (TAA) was lower in diabetic groups compared with their non-diabetic controls and it was not affected by GSE. In conclusion, GSE supplementation has limited protective effect in liver tissue of diabetic rats via affecting NO levels and was not affecting TAA.

Serum leptin, adiponectin, resistin and ghrelin levels in psoriatic patients treated with cyclosporin.

Cyclosporin has various effects on adipose tissue and glucose metabolism. This situation may lead to changes in serum levels of adipocyte-derived cytokines which have influence on the pathogenesis of psoriasis. The aim of this study was to evaluate the effect of cyclosporin treatment on some adipocyte-derived cytokines in psoriatic patients. This case-control study was performed between June 2009 and March 2010, at the Department of Dermatology of Meram School of Medicine. Serum leptin, adiponectin, resistin and ghrelin levels were assessed in 26 patients with psoriasis before and after cyclosporin treatment and body mass index-matched 26 healthy control subjects. The adipokines levels were compared between the groups. Serum leptin, ghrelin, resistin and adiponectin levels in patients with psoriasis before the treatment were higher than those of the control group but the differences were not statistically significant. A positive correlation between serum leptin and family history of psoriasis was detected (r = 0.398, P = 0.044). A strong negative correlation between the Psoriasis Area and Severity Index and serum ghrelin levels was seen (r = -0.52, P = 0.001) and there was a strong positive correlation between the Nail Psoriasis Severity Index and serum resistin levels (r = 0.62, P = 0.001). Following the treatment, a significant increase was seen in the serum level of adiponectin (P = 0.02) and resistin (P = 0.003). The correlations between the adipokines and the disease parameters before the treatment were lost after the treatment. Our results suggest that levels of some adipocyte-derived cytokines in psoriatic patients are affected by cyclosporin treatment.

Effects of grape seed extract supplementation on exercise-induced oxidative stress in rats.

The aim of the present study was to investigate the effects of grape seed extract (GSE) supplementation on exercise performance and oxidative stress in acutely and chronically exercised rats. A total of sixty-four male rats were used in the study. Rats were divided into six groups: control, chronic exercise control, acute exercise control (AEC), GSE-supplemented control, GSE-supplemented chronic exercise and GSE-supplemented acute exercise groups. Chronic exercise consisted of treadmill running at 25 m/min, 45 min/d, 5 d a week for 6 weeks. Rats in the acute exercise groups were run on the treadmill at 30 m/min until exhaustion. GSE were given at 100 mg/kg of body weight with drinking water for 6 weeks. Plasma was separated from blood samples for the analysis of oxidative stress markers. There was no significant difference in time of exhaustion between the acute exercise groups. Plasma malondialdehyde (MDA) levels were higher in the acute exercise groups and lower in the chronic exercise groups. GSE supplementation decreased MDA levels. Xanthine oxidase and adenosine deaminase activities were higher in the AEC group compared to all the other groups. NO levels were increased with both chronic exercise and GSE supplementation. Superoxide dismutase and glutathione peroxidase activities were lower in the acute exercised groups and higher in the chronic exercised groups. GSE supplementation caused an increase in antioxidant enzyme activities. In conclusion, GSE supplementation prevents exercise-induced oxidative stress by preventing lipid peroxidation and increasing antioxidant enzyme activities.

Coenzyme Q10 and its relation with oxidant and antioxidant system markers in patients with end-stage renal disease.

RATIONALE AND OBJECTIVES: Oxidative stress is increased in chronic kidney disease (CKD) patients and end-stage renal disease (ESRD) patients undergoing dialysis treatment. Coenzyme Q(10) (CoQ(10)) is a ubiquitous and strong antioxidant. Role of CoQ(10) is not fully evaluated in renal patients. We aimed to investigate the relationship of CoQ(10) with oxidant and antioxidant system markers in patients with renal disease. MATERIAL AND METHODS: Forty patients with CKD (stages 3-5) who were managed conservatively without dialysis treatment, 40 hemodialysis, and 60 chronic ambulatory peritoneal dialysis (CAPD) patients were included in the study. Biochemical and whole blood analyses were done using hospital auto-analyzers from stored samples. Serum CoQ(10), malondialdehyde (MDA), superoxide dismutase (SOD), and antioxidant activity (AOA) levels were determined. MAIN FINDINGS: There was no difference among the groups in terms of serum CoQ(10) levels. However, other components of antioxidant system, namely, SOD and AOA were significantly higher in CAPD patients when compared to CKD patients. MDA levels were not significantly different among the groups. PRINCIPAL CONCLUSION(S): The results of this study showed no difference among CKD, CAPD, and hemodialysis patients in terms of serum CoQ(10) levels.

The effect of supplementation of grape seed proanthocyanidin extract on vascular dysfunction in experimental diabetes.

Increased oxidative stress and impaired endothelium-dependent relaxation could underlie many of the vascular complications associated with diabetes. We aimed to investigate the effect of supplementation with grape seed proanthocyanidin extract (GSPE), a natural antioxidant, on vascular responses and oxidative stress in streptozotocin-induced diabetic rats. Male Sprague-Dawley rats were divided into three groups: control rats, untreated diabetic rats, and GSPE (100 mg/kg, for 6 weeks)-supplemented diabetic rats. Thoracic aorta rings of the rats were mounted in organ baths, and relaxant responses to acetylcholine (ACh), A23187, and sodium nitroprusside (SNP) were assayed in tissues precontracted with 60 mM KCl. Plasma samples used for the measurement of malondialdehyde (MDA) level and superoxide dismutase (SOD) activity. The endothelium-dependent relaxations in response to ACh and A23187 were impaired, but endothelium-independent relaxation in response to SNP did not change in diabetic rats. Supplementation with GSPE significantly improved the relaxant responses to ACh and A23187. The MDA level was significantly elevated and the plasma SOD activity was decreased in diabetic rats, but supplementation with GSPE attenuated the elevated MDA levels and increased plasma SOD activity. Thus supplementation of GSPE may attenuate oxidative stress through the inhibition of lipid peroxidation and may restore endothelial function and reduce the risk of vascular disease in diabetes.

Diabetes mellitus- and cooling-induced bladder contraction: an in vitro study.

The effects of diabetes mellitus during cooling on ACh- and KCl-induced responses were investigated in rat urinary bladder. Diabetes was induced in the rats by 50 mg/kg streptozotocin via an intraperitoneal injection. Rats' body and bladder weights were measured. The isometric tension to ACh (10(-9) - 3 × 10(-4) M) and KCl (5-100 mM) in strips of urinary detrusor muscle of diabetic and non-diabetic rats, in organ baths at 37 and 28ºC were recorded. The body weights were significantly decreased and the bladder weights increased in STZ-induced diabetic group compared to the non-diabetic group. ACh and KCl caused concentration-dependent contractions of urinary bladders from non-diabetic and STZ-induced diabetic rats. During cooling, the sensitivity and the maximal response were significantly higher than those during 37ºC, both in non-diabetic and diabetic preparations. Cooling of detrusor muscle preparations induces a graded contraction inversely proportional to the temperature in diabetic rats. It may be assumed that the cooling response involves the same mechanisms in the diabetic and non-diabetic animals.

The effect of grape seed extracts on serum paraoxonase activities in streptozotocin-induced diabetic rats.

Procyanidins, a group of flavonoids, are oligomeric forms of catechins that are abundant in red wine, grapes, cocoa, and apples. Paraoxonase acts as an antioxidant enzyme and protects low-density lipoprotein-cholesterol against oxidation. In our study we aimed to evaluate the effects of grape seed extract (GSE) on paraoxonase activities in streptozotocin-induced diabetic rats. Our study included four groups of rats: Group I (n = 8), control; Group II (n = 10), GSE-supplemented; Group III (n = 6), streptozotocin-induced diabetic; and Group IV (n = 7), GSE-supplemented diabetic rats. Serum paraoxonase activities were determined with a spectrophotometric method. Paraoxonase activities in Group III were significantly lower than in the other three groups (P < .001, P < .001, and P = .005 for Groups I, II, and IV, respectively), and Group IV showed increased paraoxonase activities compared to Group III (P = .005). This is the first study to show an association between paraoxonase status and GSE supplementation and demonstrated that GSE increased paraoxonase activities. This beneficial effect of GSE was more obvious in the diabetic group, which was more prone to atherosclerotic events compared to the healthy population.

Effects of long-term 50 Hz magnetic field exposure on the micro nucleated polychromatic erythrocyte and blood lymphocyte frequency and argyrophilic nucleolar organizer regions in lymphocytes of mice.

OBJECTIVES: We aimed to investigate the effects of weak extremely low frequency electromagnetic fields (ELF-EMFs) on the nucleus size, the silver staining nucleolar organizer regions (AgNORs), the frequency of micro nucleated peripheral blood lymphocytes (MPBLs) and the micro nucleated polychromatic erythrocytes (MPCEs). METHODS: One hundred and twenty Swiss albino mice were equally divided into 6 groups. The study groups were exposed to 1, 2, 3, 4 and 5 microT 50 Hz-EMFs for 40 days. Micronucleus number (MN) per PBL was determined.. RESULTS: ELF-EMF exposure caused a nonlinear decline of nucleus area. A sharp drop occurred in AgNOR area of 1 microT group, and following it gained an insignificantly higher level than that of the control group. The field did not change mean AgNOR numbers per nucleus of the groups. Relative AgNOR area had the highest level in 1 microT-exposure group, and the level was quite similar to that of the 5 microT-exposure group. The remaining groups had significantly lower values quite similar to that of the control level. The field exposure at any intensity did not affect significantly the frequency of either MPBLs or MPCEs. The number of MN per PBL in the 4 and 5 microT-exposure groups were significantly higher than those of the lower intensity exposure groups. The males in 4 microT-exposure group displayed the highest MN number per PBL, whereas values changed in a nonlinear manner. CONCLUSIONS: The results of the present study suggest that

Effects of coenzyme Q10 supplementation on plasma adiponectin, interleukin-6, and tumor necrosis factor-alpha levels in men.

The aim of the study was to determine the effects of coenzyme Q10 supplementation on plasma adiponectin, interleukin (IL)-6, and tumor necrosis factor (TNF )-alpha levels in sedentary men. Fourteen healthy, nonsmoking, sedentary men participated in the study. The protocol was approved by the Ethical Committee of our institution. This study was a randomized, double-blind, crossover trial. Blood samples were collected from all participants before coenzyme Q10 or placebo supplementation. The participants were randomly allocated to two groups. Seven participants received oral coenzyme Q10 (100 mg/day) supplementation, and seven participants received placebo (glucose) for 8 weeks. At the end of the 8 weeks, a second blood sampling was performed. After a 4-week washout period, placebo was given to the participants who used coenzyme Q10 the first time, and vice versa, and blood sampling was repeated. Plasma was stored at -80 degrees C until the time of analysis for adiponectin, IL-6, and TNF-alpha. Both CoQ10 and placebo supplementation did not affect plasma adiponectin and TNF-alpha levels. IL-6 level increased with coenzyme Q10 supplementation, but this increase did not differ from that seen with placebo supplementation. Coenzyme Q10 supplementation did not affect plasma adiponectin, IL-6, and TNF-alpha levels in sedentary men.

Changes in lipid peroxidation and antioxidant capacity during walking and running of the same and different intensities.

The aim was to investigate the changes in lipid peroxidation, antioxidant enzyme activities, and muscle damage in the same and different exercise intensities during walking and running. Fourteen healthy males participated in this study. The subjects' individual preferred walk-to-run transition speeds (WRTS) were determined. Each subject covered a 1.5-mile distance for 4 exercise tests; walking (WRTS-W) and running (WRTS-R) tests at WRTS, 2 kmxh-1 slower walking than WRTS (WRTS-2) and 2 kmxh-1 faster running than WRTS (WRTS+2). Blood samples were taken pre, immediately, and 30 minutes post each test. The changes in (MDA) and glutathione (GSH) levels and superoxide dismutase (SOD), catalase (CAT), and creatine kinase activities were measured. Oxygen uptake, carbon dioxide output, oxygen uptake per kilogram of body weight, and heart rate during exercises were significantly higher in both the WRTS-W and the WRTS+2 exercises compared with the WRTS-2 and WRTS-R. Oxygen consumption and energy expenditure were higher in walking than in the running exercise at the preferred WRTS and only WRTS-W exercise significantly increased MDA levels. Catalase activities were increased by WRTS-W, WRTS-R, and WRTS+2 exercises. Changes in SOD and CAT activities were not different between walking and running exercises at the preferred WRTS. Total plasma GSH increased in response to WRTS-W exercise, which could be associated with an increase in MDA. Also, total GSH levels 30 minutes postexercise were significantly lower than postexercise in WRTS-2, WRTS-W, and WRTS+2 exercises. Our results indicate that walking and running exercises at the preferred WRTS have different oxidative stress and antioxidant responses.

The effects of exercise and zinc deficiency on some elements in rats.

The objective of the present study was to determine the effects of exercise and zinc deficiency on some elements in rats. Forty adult male Sprague-Dawley species male rats were allocated to four groups as follows: Group 1: control, Group 2: zinc-deficient, Group 3: exercise in which exercise group fed with a normal diet, Group 4: zinc-deficient exercise, exercise group fed by a zinc-deficient diet for 15 days. After the procedure ended, rats in groups 3 and 4 were exercised on the treadmill for 60 min at a speed of 6 m/min until the exhaustion. The rats were decapitated 48 h after exercise together with their controls, and blood samples were collected to determine copper (Cu), iron (Fe), magnesium (Mg), calcium (Ca), and phosphorus (P) levels. The highest Cu and Fe values in the serum were obtained in group 2 (p < 0.01). The levels of these elements in group 4 were lower than those in group 2 and higher than the levels in groups 1 and 3 (p < 0.01). Serum Mg levels did not differ significantly between groups. Group 4 had the lowest serum Ca and P levels (p < 0.01). These same parameters in Group 2 were higher than those in group 4 but significantly lower than those in groups 1 and 3 (p < 0.01). There was no significant difference between Ca and P levels of groups 1 and 3. The results of the study indicate that zinc deficiency adversely affects copper, iron, calcium, and phosphorus mechanisms and that these adverse effects much more marked after an effort exercise.

The association of nocturnal serum melatonin levels with major depression in patients with acute multiple sclerosis.

The association of nocturnal serum melatonin levels was investigated in acute multiple sclerosis (MS) patients with major depression (MD). The sample comprised 13 patients with MD and 12 with no psychiatric disorders admitted to our clinic due to acute MS attacks. Psychiatric evaluation was performed with the Structured Clinical Interview for DSM-IV (SCD-I). The level of depressive symptoms was assessed with the Beck Depression Scale (BDS). Blood samples were taken from the patients to determine melatonin level at 03.30 h and 10.00 h before steroid treatment started. Melatonin levels were determined using the ELISA test. Nocturnal serum melatonin levels (21.2+/-17.1 pg/ml) of the patients with MD were significantly lower than those (51.5+/-18.3 pg/ml) of the patients without MD. A significant negative correlation was found between BDS scores and nocturnal serum melatonin levels. These findings suggest that a melatonin deficiency may be among the factors involved in the occurrence of depression in MS patients.

Coenzyme Q(10) and alpha-lipoic acid supplementation in diabetic rats: conduction velocity distributions.

Diabetic neuropathies are a family of nerve disorders caused by diabetes. Patients with diabetes can develop nerve problems at any time, but the longer a person has diabetes the greater the risk. This study aims to investigate diabetes- and coenzyme Q(10) (CoQ(10)) or alpha-lipoic acid (ALA) supplementation-induced changes in the conduction velocity (CV) distributions of rat sciatic nerve fibers. Sciatic nerve compound action potentials (CAPs) were recorded by suction electrode and CV distributions by the collision technique. Diabetes resulted in a significant increase in time to peak, rheobase and chronaxie values of these CAP waveforms, whereas the maximum depolarization, area, kinetics and CVs of both fast and slow nerve fiber groups were found to be decreased. Coenzyme Q(10) (CoQ(10)) supplementation was found to have some positive effect on the diabetes-induced alterations. CoQ(10) supplementation induced positive changes mainly in the area and fall-down phase of the kinetics of CAP waveforms, as well as rheobase, chronaxie and speed of the intermediately conducting groups ( approximately or equal to 40 m/s). alpha-Lipoic acid (ALA) supplementation did not produce statistically significant effects. This study has shown for the first time that diabetes induces a shift of actively contributing nerve fibers toward slower CVs, and supplementation with CoQ(10) not only stopped this shift but also tended to restore velocities toward those of the age-matched control group. In addition to its effects on mitochondrial alterations, these positive effects of CoQ10 on diabetic neuropathy can be attributed to its antioxidant activity.

Single dose of tiotropium improves the 6-minute walk distance in chronic obstructive pulmonary disease.

The aim of this study was to evaluate the effect of a single dose of tiotropium on the exercise capacity of stable chronic obstructive pulmonary disease (COPD) patients. The study was a randomized, placebo-controlled, double-blind, cross-over study. Forty-four stable COPD patients with moderate to severe airway obstruction were selected according to the GOLD criteria. The regular anticholinergic therapies of the patients were interrupted one week before the test. In the morning hours of the first day, half the group was given one capsule (18 mcg) of tiotropium and the other half was given placebo as inhalation using the HandiHaler device. Before and 120 min after the medication, the 6-min walk test was performed. Oxygen saturation, modified Borg dyspnea ratings, blood pressure, and heart rate were recorded before and after the test. The same procedure was repeated at the same time on the third day but this time the patients were given placebo if they used tiotropium on the first day and vice versa. Before using tiotropium or placebo there was no difference between 6-min walk distances. The 6-min walk distance after the use of tiotropium (429.3 +/- 70.6 m) was significantly longer than that after the use of placebo (414.7 +/- 74.6 m). The changes in Borg dyspnea ratings and arterial oxygen saturation values with tiotropium and placebo use were not significant. We conclude that exercise capacity might be improved by using a single-dose tiotropium inhalation in moderate to severe COPD patients.