Theodore Parthimos

Harokopion University of Athens, Athens, Attiki, Greece

Are you Theodore Parthimos?

Claim your profile

Publications (15)36.41 Total impact

  • Article: Maternal–neonatal erythrocyte membrane Na+, K+-ATPase and Mg2+-ATPase activities in relation to the mode of delivery
    [show abstract] [hide abstract]
    ABSTRACT: Free radical production and high catecholamine levels are implicated in the modulation of Na+, K+-ATPase, and Mg2+-ATPase activities. The aim of this study was to investigate the effect of the mode of delivery on the above-mentioned enzyme activities in maternal–neonatal erythrocyte membrane. Women with normal pregnancy (N=30) were divided into two groups: Group A (N=16) with normal labor and vaginal delivery, and Group B (N=14) with scheduled cesarean section; 20 non-pregnant women were the controls. Blood was obtained from controls and mothers, pre- versus post-delivery, and from the umbilical cord (CB). Total antioxidant status (TAS), membrane enzyme activities, and catecholamine blood levels were measured with a commercial kit, spectrophotometrically, and by HPLC methods, respectively. The results showed that: TAS levels, catecholamine, and the membrane enzyme activities were similar in the two groups of mothers pre-delivery, whereas both enzyme activities were lower than those of controls. TAS levels were reduced whereas Na+, K+-ATPase activities (0.35±0.03 vs. 0.65±0.06μmolPi/h×mg protein, P<0.001), and catecholamine levels were increased post-delivery in mothers of Group A and unaltered in Group B (0.38±0.02 vs. 0.40±0.03μmolPi/h×mg protein, P>0.05), at the same times of study. Mg2+-ATPase activities remained unaltered in both groups of mothers and newborns. Na+, K+-ATPase activity was similarly lower in the CB of neonates than those of their mothers, pre-delivery. Our results suggest that: (a) during a normal vaginal delivery process, the low TAS and the increased levels of catecholamines may increase Na+, K+-ATPase activity, post-delivery; (b) the low enzyme activities evaluated in mothers pre-delivery may be due to the high estrogen levels and those in newborns due to perinatal immaturity.
    Arbeitsphysiologie 04/2012; 103(5):501-508. · 2.15 Impact Factor
  • Article: Evidence for the participation of the stimulated sympathetic nervous system in the regulation of carnitine blood levels of soccer players during a game.
    [show abstract] [hide abstract]
    ABSTRACT: Catecholamines and carnitine blood levels are closely implicated with training. The aim of the study was to investigate the effect of sympathetic nervous system stimulation on carnitine and its fraction levels during training. Blood was obtained from 14 soccer players pregame, at intermission, and postgame. Catecholamines were measured with high-performance liquid chromatography methods; muscle enzymes creatine kinase and lactate dehydrogenase as well as lactate, pyruvate, and total antioxidant status with commercial kits; and carnitine and fraction levels with tandem mass spectrometry. Total antioxidant status (2.97 +/- 0.13 vs 0.96 +/- 0.10 mmol/L, P < .01) as well as free carnitine levels (20.47 +/- 4.0 vs 12.30 +/- 2.8 micromol/L, P < .001) were remarkably decreased especially postgame. Total acylcarnitines (5.20 +/- 1.8 vs 9.42 +/- 3.0 micromol/L, P < .001) and especially total very long-chain acylcarnitines (0.80 +/- 0.01 vs 1.85 +/- 0.03 micromol/L, P < .001) as well as catecholamine levels (adrenaline: 230 +/- 31 vs 890 +/- 110 pmol/L, P < .01; noradrenaline: 1.53 +/- 0.41 vs 3.7 +/- 0.6 nmol/L, P < .01) were significantly increased in players postgame. A statistically significant inverse correlation was found between adrenaline and free carnitine (r = -0.51, P < .01); and a positive correlation was found between adrenaline, total acylcarnitines (r = 0.58, P < .01), and total long-chain acylcarnitine (r = 0.49, P < .01). The significant positive correlation of adrenaline levels with total acylcarnitine and total long-chain acylcarnitine blood levels in athletes as well as the inverse correlation with free carnitine levels may indicate participation of the stimulated sympathetic nervous system in the regulation of some carnitine fraction levels during exercise.
    Metabolism: clinical and experimental 06/2009; 58(8):1080-6. · 2.59 Impact Factor
  • Article: Significant reduction of erythrocyte glucose-6-phosphate dehydrogenase activity in soccer-players during play. Evidence for catecholamine mediated enzyme inhibition.
    Clinical Chemistry and Laboratory Medicine 02/2009; 47(5):621-4. · 2.15 Impact Factor
  • Article: The effect of the mode of delivery on the maternal-neonatal erythrocyte membrane acetylcholinesterase activity.
    [show abstract] [hide abstract]
    ABSTRACT: Free radical production and high catecholamine levels are implicated with the modulation of acetylcholinesterase (AChE) activity. To investigate the effect of the mode of delivery on maternal-neonatal erythrocyte membrane AChE activity. Some women with normal pregnancy (N = 30) were divided into two groups: group A (N = 16) with normal labour and vaginal delivery and group B (N = 14) with scheduled Cesarean section, twenty non-pregnant women were the controls. Blood was obtained from controls and from mothers pre- vs post-delivery as well as from the umbilical cord (CB). Total antioxidant status (TAS), membrane AChE activities and catecholamine blood levels were measured with a commercial kit, spectrophotometrically and HPLC methods, respectively. TAS and catecholamine levels as well as membrane AChE activities were similar in the two groups of mothers pre-delivery and in controls. TAS levels were reduced whereas AChE activities and catecholamine levels were increased post-delivery in mothers of group A and unaltered in group B at the same times of study. AChE activity was similarly lower in the CB of neonates than those of their mothers pre-delivery. During a normal delivery process, the low TAS, the increased levels of catecholamines and the increased AChE activity, post-delivery, may be due to the increased stress due to the participation of uterus and skeletal muscles as during endurance exercise. The low AChE activity in newborns may be related to perinatal immaturity.
    Clinical biochemistry 08/2008; 41(10-11):818-23. · 2.02 Impact Factor
  • Article: Maternal-neonatal erythrocyte membrane Na(+), K (+)-ATPase and Mg (2+)-ATPase activities in relation to the mode of delivery.
    [show abstract] [hide abstract]
    ABSTRACT: Free radical production and high catecholamine levels are implicated in the modulation of Na(+), K(+)-ATPase, and Mg(2+)-ATPase activities. The aim of this study was to investigate the effect of the mode of delivery on the above-mentioned enzyme activities in maternal-neonatal erythrocyte membrane. Women with normal pregnancy (N = 30) were divided into two groups: Group A (N = 16) with normal labor and vaginal delivery, and Group B (N = 14) with scheduled cesarean section; 20 non-pregnant women were the controls. Blood was obtained from controls and mothers, pre- versus post-delivery, and from the umbilical cord (CB). Total antioxidant status (TAS), membrane enzyme activities, and catecholamine blood levels were measured with a commercial kit, spectrophotometrically, and by HPLC methods, respectively. The results showed that: TAS levels, catecholamine, and the membrane enzyme activities were similar in the two groups of mothers pre-delivery, whereas both enzyme activities were lower than those of controls. TAS levels were reduced whereas Na(+), K(+)-ATPase activities (0.35 +/- 0.03 vs. 0.65 +/- 0.06 micromol Pi/h x mg protein, P < 0.001), and catecholamine levels were increased post-delivery in mothers of Group A and unaltered in Group B (0.38 +/- 0.02 vs. 0.40 +/- 0.03 micromol Pi/h x mg protein, P > 0.05), at the same times of study. Mg(2+)-ATPase activities remained unaltered in both groups of mothers and newborns. Na(+), K(+)-ATPase activity was similarly lower in the CB of neonates than those of their mothers, pre-delivery. Our results suggest that: (a) during a normal vaginal delivery process, the low TAS and the increased levels of catecholamines may increase Na(+), K(+)-ATPase activity, post-delivery; (b) the low enzyme activities evaluated in mothers pre-delivery may be due to the high estrogen levels and those in newborns due to perinatal immaturity.
    Arbeitsphysiologie 07/2008; 103(5):501-8. · 2.15 Impact Factor
  • Article: The in vivo and in vitro effects of L-carnitine supplementation on the erythrocyte membrane acetylcholinesterase, Na+, K+-ATPase and Mg2+-ATPase activities in basketball players.
    [show abstract] [hide abstract]
    ABSTRACT: We investigated whether the activities of erythrocyte membrane acetylcholinesterase (AChE), Na+, K+-ATPase and Mg2+-ATPase are modulated in basketball players pre- vs. post-forced training with or without L-carnitine (L-C) supplementation. Blood was obtained from 10 male players pre-game (group A) and post-game (group B) and after 1 month L-C supplementation (2 g/24 h orally) pre-training (group C) and post-training (group D). Lactate, pyruvate and total antioxidant status (TAS) were measured with commercial kits, catecholamines with HPLC and the enzyme activities spectrophotometrically. Lactate, pyruvate, AChE, Na+, K+-ATPase and catecholamines were increased (p<0.001) and TAS was decreased (p<0.001) in group B. In contrast, TAS remained unaltered and the all enzyme activities were reduced (p<0.001) in group D at the same time of study. Mg2+-ATPase activity remained unchanged. In vitro incubation of the modulated AChE and Na+, K+-ATPase with L-C (25 microM) from group B and group D resulted in a non-significant reduction of the enzymes in group B and complete restoration of their activities in group D. The increase of AChE and Na+, K+-ATPase activities may be due to the elevation of catecholamines in group B. Carnitine utilization by the muscles during training may result in a reduction of the enzyme activities (group D). The latter is supported by the recovery of the enzyme activities after incubation of the membranes from group D with L-C.
    Clinical Chemistry and Laboratory Medicine 01/2008; 46(1):137-42. · 2.15 Impact Factor
  • Article: The effect of alpha-Tocopherol supplementation on training-induced elevation of S100B protein in sera of basketball players.
    [show abstract] [hide abstract]
    ABSTRACT: To investigate the effect of alpha-Tocopherol (alpha-T) supplementation on S100B elevated serum levels in basketball players' training. Blood was obtained from 10 basketball players pre-exercise (group A), post-exercise (group B) and after 30 days on alpha-T (200 mg/24 h orally) supplementation pre- (group C) and post-training (group D). Blood samples were taken for the evaluation of total antioxidant status (TAS), alpha-T and catecholamines in plasma and S100B and muscle enzyme levels in serum. TAS, muscle enzymes: creatine kinase (CK), lactate dehydrogenase (LDH), and S100B protein levels were measured with commercial kits, whereas alpha-T and catecholamine levels with HPLC methods. TAS was found higher in the groups with alpha-T addition (groups C and D) than in the other ones. On the contrary, CK, LDH and S100B were remarkably lower (116.8+9.5 U/L, 427+22 U/L, 0.18+0.04 microg/L, respectively) in group D than those in group B (286+12 U/L, 688+26 U/L, 0.28+0.06 microg/L, p<0.001, respectively). S100B levels were negatively correlated with TAS (r=-0.64, p<0.001) and positively with CK levels (r=0.58, p<0.001). alpha-T supplementation may reduce S100B increased release from muscle and nerves induced by training. S100B serum evaluation may be a useful biomarker for the effect of training on the participation of the neuromuscular system.
    Clinical Biochemistry 08/2007; 40(12):900-6. · 2.08 Impact Factor
  • Article: An in vivo and in vitro study of erythrocyte membrane acetylcholinesterase, (Na+, K+)-ATPase and Mg2+-ATPase activities in basketball players on alpha-tocopherol supplementation. The role of L-carnitine.
    [show abstract] [hide abstract]
    ABSTRACT: Vitamin E (alpha-tocopherol, alpha-Te) and carnitine reduce lipid peroxidation. THE AIM WAS TO: To investigate the erythrocyte membrane acetylcholinesterase (AChE), Na+, K+-ATPase and Mg2+-ATPase activities in basketball players with or without alpha-Te supplementation, before and after training. In vitro, we aimed to find out any additional effect of L-carnitine (L-C) on the modulated enzyme activities. Blood was obtained from 10 players before (group A), after exercise (group B) and after 1 month on alpha-Te (200 mg/24 h orally) supplementation before (group C) and after the game (group D). Lactate, pyruvate, muscle enzyme activities and total antioxidant status (TAS) were measured with commercial kits. Catecholamines and alpha-Te were determined with HPLC methods and membrane enzyme activities spectrophotometrically. Lactate, pyruvate, muscle enzymes and catecholamine levels were increased (P<0.001) in all groups after training. Alpha-Te levels and Mg2+-ATPase activity remained unaltered before and after exercise. TAS was decreased in the groups after the game. AChE activity was increased in group B (P<0.01) and decreased in group D (P<0.01). After the exercise, Na+, K+-ATPase activity was increased in group B and remained unaltered in group D. In vitro incubation of membranes from group D with L-C resulted in a partially restoration of the membrane AChE activity, whereas Na+, K+-ATPase and Mg2+-ATPase activities were found unchanged. Alpha-Te supplementation in basketball players results in an increase of TAS and AChE activity, whereas the other enzyme activities were found unchanged. L-C addition may restore AChE activity, which was modulated by training in players on alpha-Te.
    Clinical Nutrition 03/2007; 26(1):63-9. · 3.73 Impact Factor
  • Article: L-cysteine supplementation prevents exercise-induced alterations in human erythrocyte membrane acetylcholinesterase and Na+,K+-ATPase activities.
    [show abstract] [hide abstract]
    ABSTRACT: L-Cysteine (L-Cys) is implicated in the reduction of free radical production. The aim of this study was to investigate whether L-Cys supplementation prevents modulation of the activities of erythrocyte membrane acetylcholinesterase (AChE), Na(+),K(+)-ATPase and Mg(2+)-ATPase induced by free radicals in basketball players during training. Blood was obtained from 10 basketball male players before (group A) and after a game (group B) and after 1 week of L-Cys (0.5 g/24 h orally) supplementation before (group C) and after training (group D). Lactate, pyruvate and total antioxidant status (TAS) were measured using commercial kits and the enzyme activities were determined spectrophotometrically. Both lactate and pyruvate levels remarkably increased after exercise. In contrast, TAS levels significantly decreased in group B, increased in group C and then declined (group D), reaching those of group A. AChE activity was statistically increased post-exercise (3.98+/-0.04 Delta OD/min x mg protein) compared with pre-training (2.90+/-0.05 Delta OD/min x mg protein, p<0.01). Na(+),K(+)-ATPase activity was also higher post-exercise (1.27+/-0.05 micromol Pi/h x mg protein) than that pre-exercise (0.58+/-0.04 micromol Pi/h x mg protein, p<0.001). When the players were supplemented with L-Cys, both AChE and Na(+),K(+)-ATPase activities remained unaltered post-exercise. Mg(2+)-ATPase activities were unchanged in all groups studied. L-Cys supplementation may protect the enzyme activities studied against stimulation induced by free radical production during training in athletes by ameliorating their total antioxidant capacity.
    Clinical Chemistry and Laboratory Medicine 02/2007; 45(1):67-72. · 2.15 Impact Factor
  • Article: alpha-Tocopherol supplementation restores the reduction of erythrocyte glucose-6-phosphate dehydrogenase activity induced by forced training.
    [show abstract] [hide abstract]
    ABSTRACT: Erythrocyte glucose-6-phosphate dehydrogenase (G6PD) activity is closely related to free radical production. alpha-Tocopherol (alpha-T) is implicated with the reduction of lipid peroxidation. To investigate the effect of training and alpha-T supplementation on the erythrocyte G6PD activity. Blood was obtained from 10 basketball players pre-game (group A), post-game (group B) and after 30 days on alpha-T (dl-alpha-tocopheryl-acetate, 200mg 24h(-1) orally) supplementation pre- (group C) and post-training (group D). alpha-T and catecholamines were evaluated with HPLC methods and creatine kinase, lactate dehydrogenase, total antioxidant status (TAS) and G6PD activity with commercial kits. TAS was increased in the groups with alpha-T addition (groups C and D). Post-exercise, TAS and G6PD activity were remarkably higher (2.10+/-0.13mmoll(-1), 7.92+/-1.5Ug(-1)Hb, respectively) in group D than those in group B (0.92+/-0.10mmoll(-1), 4.8+/-1.4Ug(-1)Hb, p<0.01, respectively). G6PD activity positively correlated with TAS (r=0.64, p<0.001) in all the studied groups. Supplementation with alpha-T may protect G6PD activity from reduction induced by forced training.
    Pharmacological Research 11/2006; 54(5):373-9. · 4.44 Impact Factor
  • Article: L-cysteine supplementation protects the erythrocyte glucose-6-phosphate dehydrogenase activity from reduction induced by forced training.
    [show abstract] [hide abstract]
    ABSTRACT: L-cysteine (L-cys) is implicated in the reduction of free radical production. To investigate the effect of training and L-cys supplementation on the erythrocyte glucose-6-phosphate dehydrogenase (G6PD) activity. Blood was obtained from 10 basketball players pre-game (group A), post-game (group B) and after 1 week on L-cys (0.5 g/24 h orally) supplementation pre- (group C) and post-training (group D). Total antioxidant status (TAS) and G6PD activity were evaluated with commercial kits. TAS increased in the groups with l-cys addition (group C and group D). Post-exercise, TAS and G6PD activity were remarkably higher (1.48+/-0.12 mmol/L, 8.9+/-1.7 U/g Hb, respectively) in group D than those in group B (0.92+/-0.10 mmol/L, 4.8+/-1.6 U/g Hb, p<0.01). G6PD activity positively correlated with TAS (r=0.70, p<0.001 pre- and r=0.61, p<0.001 post-training) in all the studied groups. G6PD activity is lowered by training probably due to free radical action. L-cys supplementation may protect G6PD activity from reduction by increasing total antioxidant capacity and glutathione production. G6PD activity should be evaluated in the blood of athletes of Mediterranean origin and female G6PD-deficient heterozygotes.
    Clinical Biochemistry 11/2006; 39(10):1002-6. · 2.08 Impact Factor
  • Article: The beneficial effect of L-cysteine supplementation on DNA oxidation induced by forced training.
    [show abstract] [hide abstract]
    ABSTRACT: Forced training is closely implicated with free radicals production and indication of tissue damage as well as DNA oxidation. To investigate the effect of L-cysteine (L-cys) supplementation on DNA oxidative damage found in basketball players after forced training. Blood was obtained from 10 players pre-game (group A), post-game (group B) and after 1 month L-cys (0.5 g 24 h(-1), orally) supplementation, pre- (group C) and post-training (group D). Total antioxidant status (TAS) and the biomarker of DNA oxidative damage 8-hydroxy-2-deoxyguanosine (8-OHdG) as well as creatine kinase (CK) and lactate dehydrogenase (LDH) were measured with commercial kits. TAS was increased in the groups with L-cys (group C and group D). Post-exercise 8-OHdG levels, CK and LDH were remarkably lower (0.16+/-0.03 ng ml(-1), 115+/-15 U l(-1), 417+/-90 U l(-1), respectively) in group D than those in group B (0.36+/-0.05 ng ml(-1), 286+/-12 U l(-1), 688+/-88U l(-1), p<0.001, respectively). 8-OH dG levels were negatively correlated with TAS(r=-0.718, p<0.01) and positively with CK levels(r=0.590, p<0.01). L-cys supplementation in basketball players may reduce DNA damage induced by training. The sulfur-containing amino acid may protect muscle cells "death" by increasing TAS and the cellular defense against oxidative stress.
    Pharmacological Research 04/2006; 53(4):386-90. · 4.44 Impact Factor
  • Article: alpha-tocopherol supplementation reduces the elevated 8-hydroxy-2-deoxyguanosine blood levels induced by training in basketball players.
    [show abstract] [hide abstract]
    ABSTRACT: The aim of the present study was to investigate the effect of alpha-tocopherol (alpha-Te) supplementation on DNA oxidative damage induced by heavy training in basketball players. Blood was obtained from 10 players before (group A) and after training (group B) and after 1 month on alpha-Te (200 mg/day, orally) supplementation, before (group C) and after training (group D). Total antioxidant status (TAS), muscle enzyme activities and the biomarker of DNA oxidation, 8-hydroxy-2-deoxyguanosine (8-OHdG), were measured using commercial kits. alpha-Te and catecholamine blood levels were determined using HPLC methods. TAS was higher in the groups with alpha-Te (groups C and D). Levels of 8-OHdG and muscle creatine kinase (CK) and lactate dehydrogenase (LDH) were remarkably lower (0.20+/-0.03 ng/mL, 120+/-15 U/L and 430+/-90 U/L, respectively) in the group with alpha-Te (group D) than in group B (0.42+/-0.05 ng/mL, 286+/-12 U/L and 688+/-88 U/L, respectively; p<0.001). 8-OHdG levels were negatively correlated to TAS and positively to CK levels. alpha-Te supplementation may reduce DNA oxidation induced by training by protecting muscle cell "death" from glutamate entry and/or by elevation of TAS via amelioration of lipid peroxidation.
    Clinical Chemistry and Laboratory Medicine 01/2006; 44(8):1004-8. · 2.15 Impact Factor
  • Article: Erythrocyte membrane Na+,K+-ATPase and Mg2+-ATPase activities in subjects with methylenetetrahydrofolate reductase (MTHFR) 677 C-->T genotype and moderate hyperhomocysteinaemia. The role of L-phenylalanine and L-alanine.
    [show abstract] [hide abstract]
    ABSTRACT: Increased homocysteine (Hcy) blood levels are correlated with vascular and neurological problems. The aim of our study was to investigate erythrocyte membrane Na(+),K(+)-ATPase and Mg(2+)-ATPase activities in patients with methylenetetrahydrofolate reductase (MTHFR) 677 C-->T genotype. Blood was obtained from 25 patients before and after folic acid supplementation and from controls (n=30) once. Plasma folate, vitamin B(12) and total antioxidant status (TAS) were measured using commercial kits, Hcy was determined by HPLC and membrane enzyme activities were measured spectrophotometrically. Mg(2+)-ATPase remained unaltered. Membrane Na(+),K(+)-ATPase activity was remarkably increased in patients (0.77+/-0.06 micromol Pi/h x mg protein) and decreased to normal levels (0.52+/-0.05 micromol Pi/h x mg protein; p<0.001) after therapy. TAS did not differ significantly before and after treatment. Hcy levels were significantly higher before therapy (25.4+/-2.8 micromol/L) than levels after therapy (12.1+/-2.0 micromol/L; p<0.001) and in controls (10.5+/-2.5 micromol/L, p<0.001). In vitro, L-phenylalanine (Phe) reversed to normal the stimulated enzyme from patients before therapy. In addition, Phe incubation of the Hcy activated membrane Na(+),K(+)-ATPase from controls resulted in restoration of its activity, whereas L-alanine (Ala) incubation protected the enzyme from Hcy activation. The increased membrane Na(+),K(+)-ATPase activity may be due to high -SH group Hcy levels. In vitro, Phe reversed the increase in enzyme activity induced by Hcy in controls, as well as the stimulated membrane enzyme in untreated patients. Ala protected the enzyme from Hcy action.
    Clinical Chemistry and Laboratory Medicine 01/2006; 44(4):423-7. · 2.15 Impact Factor
  • Article: The effect of α-Tocopherol supplementation on training-induced elevation of S100B protein in sera of basketball players
    [show abstract] [hide abstract]
    ABSTRACT: Objective:To investigate the effect of α-Tocopherol (α-T) supplementation on S100B elevated serum levels in basketball players' training.Design:Blood was obtained from 10 basketball players pre-exercise (group A), post-exercise (group B) and after 30 days on α-T (200 mg/24 h orally) supplementation pre- (group C) and post-training (group D). Blood samples were taken for the evaluation of total antioxidant status (TAS), α-T and catecholamines in plasma and S100B and muscle enzyme levels in serum.Methods:TAS, muscle enzymes: creatine kinase (CK), lactate dehydrogenase (LDH), and S100B protein levels were measured with commercial kits, whereas α-T and catecholamine levels with HPLC methods.Results:TAS was found higher in the groups with α-T addition (groups C and D) than in the other ones. On the contrary, CK, LDH and S100B were remarkably lower (116.8 + 9.5 U/L, 427 + 22 U/L, 0.18 + 0.04 μg/L, respectively) in group D than those in group B (286 + 12 U/L, 688 + 26 U/L, 0.28 + 0.06 μg/L, p < 0.001, respectively). S100B levels were negatively correlated with TAS (r = − 0.64, p < 0.001) and positively with CK levels (r = 0.58, p < 0.001).Conclusions:α-T supplementation may reduce S100B increased release from muscle and nerves induced by training. S100B serum evaluation may be a useful biomarker for the effect of training on the participation of the neuromuscular system.
    Clinical Biochemistry.