european college of sport science

PP-BC01 Biochemistry 1
Purpose: The main purpose of the present study was to investigate the effect of adrenaline on glycogen synthase activity after contraction.
Furthermore, the effect of adrenaline on insulin-mediated glycogen synthase activation was investigated.
Methods: Rat epitrochlearis muscles were stimulated electrically in vitro for 30 min; non-contracted muscles served as controls. After
contraction, muscles were incubated 15 min with or without adrenaline. Non-contracted muscles were also incubated with insulin in the
presence or absence of adrenaline. Muscle glycogen synthase activity was analysed to achieve kinetic data for GS affinity for UDPglucose
and affinity for glucose 6-phosphate (fractional velocity).
Results: Muscle contraction reduced glycogen content from 196.4±10.8 mmol/kg to 93.7±4 mmol/kg dry weight (p < 0.05, n=8 in each
group). Furthermore, glycogen synthase fractional activity increased from 10.4±0.9 % (basal) to 51.9±1.3 % 15 min after contraction.
Adrenaline reduced glycogen synthase fractional activity to 4.1±0.3 % in non-contracted muscles. In contracted muscles, glycogen synthase
fractional activity remained elevated (25.5 ±6.0 %) when adrenaline was present. Insulin increased GS fractional activity to 17±1.3 %,
and adrenaline completely blocked insulin-stimulated glycogen synthase fractional activity (9.8±1.4 %). Glycogen synthase Km for UDPglucose
decreased from 0.65±0.04 (basal) to 0.15±0.01 mM after contraction. Insulin reduced glycogen synthase Km for UDP-glucose to
0.42 ±0.02 mM. Adrenaline did not significantly influence glycogen synthase Km for UDP-glucose.
Conclusions: Muscle contraction is a much stronger activator of glycogen synthase than insulin, and glycogen synthase fractional activity
remains high even when adrenaline is present in contracted muscles. Insulin-mediated glycogen synthase activation, on the other hand,
is completely blocked by adrenaline.
THE EFFECTS OF A WATER POLO GAME ON THE BLOOD REDOX STATUS OF MALE WATER POLO PLAYERS.
PETRIDIS, L., JAMURTAS, A.Z., NIKOLAIDIS, M.G., VESKOUKIS, A., KOURETAS, D.
UNIVERSITY OF THESSALY, TRIKALA, 42100, GREECE
The purpose of this study was to examine the effects of a single water polo game on the blood redox status of male water polo players.
Twelve male adult athletes (25.8±3.7 yrs) participated in the study and blood samples were taken before and after a water polo game of
the Greek national championship. Mean playtime was 42.8 ± 9.4 min, which corresponded to 78.12±17.14% of the total playtime. Blood
lactate concentration after the game reached considerably high values (9.16±3.91 mmol/L). Blood volume didn’t change after the game.
Thiobarbituric acid-reactive substances (TBARS) increased significantly following the game (44%) whereas there was no difference in
oxidized glutathione concentration (GSSG), protein carbonyls, catalase activity and total antioxidant capacity. Eventhough the results
suggest that an intense exercise, like a water polo game, can induce blood oxidative stress, as it is indicated by the increase of TBARS,
the absence of change in the other redox status indices measured in this study, indicate that further studies need to be done in this field
to elaborate a possible connection between this type of activity and the redox status of the athletes.
EFFECT OF RUNNING EXERCISE ON THIOL REDOX STATUS AND INFLAMMATORY MEDIATORS IN HEALTHY UNTRAINED
MEN
ZEMBRON-LACNY, A., OSTAPIUK-KAROLCZUK, J., NACZK, M., GAJEWSKI, M., SZYSZKA, K.
PHYSICAL CULTURE GORZOW WLKP. UNIVERSITY OF PHYSICAL EDUCATION POZNAN, PUBLIC COUNTY HOSPITAL GORZOW WLKP.
Introduction: Glutathione is the major non-protein thiol and one of the reactive oxygen species (ROS) sensors engaged in cellular control
of thiol redox. The ratio of reduced (GSH) to oxidised glutathione (GSSG) plays an essential role in regulating thiol-depend metabolic
pathways. Changes in thiol redox affect transcriptional activity via activation or inhibition of transcriptional factors, finally modulating the
synthesis of many molecules such as cytokines (Allen and Tresini 2000, Ji et al. 2006). The present study was designed to evaluate the
plasma marker of ROS activity and pro- and anti-inflammatory cytokines, and their relationship with thiol redox status in nonathletes
exposed to running exercise.
Method: Twelve untrained male subjects performed 90-min run at 60% VO2max. Blood was sampled before, 20 min, 6 h, 24 h and 48 h
following exercise to measure blood thiol redox status (GSHt - 2GSSG/ GSSG), plasma concentrations of interleukin IL-beta1, IL-4, IL-6, IL-
10, tumour necrosis factor (TNF)-alpha and 8-isoprostane as a marker of ROS activity. The post-exercise values were corrected for
changes in plasma volume.
Results: The running exercise caused significant increase in thiol redox status at 6 h, 24 h and 48 h rest. The pro-inflammatory cytokines
did not change following exercise whereas anti-inflammatory IL-6 and IL-10 increased 5-fold and 1.76-fold at 20 min rest. Changes in IL-6
and IL-10 levels were independent of thiol redox status but were associated with 8-isoprostane concentration. 8-isoprostane increased at
20 min and 6 h rest and directly correlated with IL-6 (r = 0.761) and IL-10 (r = 0.617).
Discussion: Our study has shown 1) changes in thiol redox status and anti-inflammatory cytokines in nonathletes performed running
exercise and 2) an integration of changes anti-inflammatory cytokines with marker of ROS activity but no relationship with thiol redox
status.
References
Allen GR, Tresini M. (2000). Free Radic Biol Med, 28, 463-499. Ji LL, Gomez-Cabrera MC, Vina J. (2006). Ann N Y Acad Sci, 1067, 425-435.
THE LEVELS OF PRO- AND ANTI-INFLAMMATORY CYTOKINES AND REACTIVE OXYGEN AND NITROGEN SPECIES IN
NON-ATHLETES EXPOSED TO RUNNING EXERCISE
OSTAPIUK-KAROLCZUK, J., ZEMBRON-LACNY, A., NACZK, M., GAJEWSKI, M., SZYSZKA, K.
FACULTY OF PHYSICAL CULTURE GORZOW WLKP., UNIVERSITY OF PHYSICAL EDUCATION POZNAN, PUBLIC COUNTY HOSPITAL GORZOW
WLKP. (POLAND)
Introduction: The induction of reactive oxygen and nitrogen species (RONS) by physical exercise is well documented in both animal and
human studies. RONS are physiological products of aerobic metabolism, and impact on variety of metabolic processes including gene
expression, protein turnover, inflammatory reaction, arachidonic acid immobilisation, cellular differentiation etc. RONS are released from
muscle, endothelial, and immune cells to stimulate changes in the immune status related to the cytokine synthesis (Kosmidou et al. 2002,
Valko et al. 2007). The aim of the study was to determine the changes in RONS and pro- and anti-inflammatory cytokines levels in response
to running exercise.
Method: Twelve untrained male subjects performed 90-min run at 60% VO2max on a treadmill. Blood was sampled before, 20 min, 6 h,
24 h and 48 h following exercise to measure plasma concentrations of hydrogen peroxide (H2O2), nitric oxide (NO), interleukin IL-1beta,
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ANNUAL CONGRESS OF THE EUROPEAN COLLEGE OF SPORT SCIENCE