The effect of L-carnitine on carbonic anhydrase level in rats exposed to exhaustive exercise and hypothermic stress

L-Carnitine is a quaternary ammonium compound biosynthesized from the amino acids lysine and methionine. It plays an important regulatory role in the mitochondria and is required for the transport of fatty acids from the cytosol into the mitochondria during the breakdown of lipids or fats for the generation of metabolic energy. The functions of L-carnitine in skeletal muscle are critical to sustaining normal bioenergetics during exercise. Carbonic anhydrase (CA; carbonate hydrolyase, EC 4.2.1.1) is a well-characterized pH regulatory enzyme in most tissues including erythrocytes and catalyzes reversible hydration of CO2 to HCO3- and H+. The only known physiological function of the CA isozymesis to facilitate the interconversion of CO2 and HCO3 -, Therefore they play key roles in diverse processes, such as physiological pH control and gas balance, calcification, and photosynthesis. In the presentstudy, the effect of L-carnitine on carbonic anhydrase levels in rats exposed to hypothermic stress was investigated. For this purposes, 24 healthy Spraque Dawley male rats were divided into four groups: thefirst group made exhaustive swimming exercises at the temperature of 18°C; to the second group Lcarnitine was given and exhaustive swimming exercises made at the temperature of 18°C; to the thirdgroup (sedentary group) only L-carnitine was given; and the last group (sedentary group) served as control. The results obtained from the present study demonstrated that the biggest inhibition was observed in the group that was given L-carnitine and made exhaustive swimming exercises at the temperature of 18°C. There were differences between groups 1 and 2, 3 and 4 (

Endurance training attenuates the oxidative stress due to acute exhaustive exercise in rat liver

The aim of this study was to investigate whether an 8-week treadmill training attenuates exerciseinduced oxidative stress in rat liver. Male rats were divided into untrained and trained groups. Endurance training consisted of treadmill running at a speed of 2.1 km/h, 1.5 h/day, 5 days a week for 8 weeks. To see the effects of endurance training on acute exhaustive exercise induced oxidative stress, untrained and trained rats were further devided into two groups: animals killed at rest and those killed after acute exhaustive exercise, in which the rats run at 2.1 km/h (10% uphill) until exhaustion. Acute exhaustive exercise increased malondialdehyde level in untrained but not in trained rats. It decreased the activity of glutathione peroxidase and total (enzymatic plus non-enzymatic) superoxide scavenger activity in untrained rats and catalase activity in trained rats. However, it did not affect glutathione S-transferase, glutathione reductase, superoxide dismutase and non-enzymatic superoxide radical scavenger activities in both trained and untrained rats. On the other hand, endurance training decreased glutathione peroxidase and glutathione S-transferase activities. The results suggested that endurance training attenuated exercise-induced oxidative stress in liver, probably by preventing the decreases in glutathione peroxidase and total superoxide scavenger activities during exercise. © 2008 Akadémiai Kiadó

Endurance training attenuates the oxidative stress due to acute exhaustive exercise in rat liver

The aim of this study was to investigate whether an 8-week treadmill training attenuates exerciseinduced oxidative stress in rat liver. Male rats were divided into untrained and trained groups. Endurance training consisted of treadmill running at a speed of 2.1 km/h, 1.5 h/day, 5 days a week for 8 weeks. To see the effects of endurance training on acute exhaustive exercise induced oxidative stress, untrained and trained rats were further devided into two groups: animals killed at rest and those killed after acute exhaustive exercise, in which the rats run at 2.1 km/h (10% uphill) until exhaustion. Acute exhaustive exercise increased malondialdehyde level in untrained but not in trained rats. It decreased the activity of glutathione peroxidase and total (enzymatic plus non-enzymatic) superoxide scavenger activity in untrained rats and catalase activity in trained rats. However, it did not affect glutathione S-transferase, glutathione reductase, superoxide dismutase and non-enzymatic superoxide radical scavenger activities in both trained and untrained rats. On the other hand, endurance training decreased glutathione peroxidase and glutathione S-transferase activities. The results suggested that endurance training attenuated exercise-induced oxidative stress in liver, probably by preventing the decreases in glutathione peroxidase and total superoxide scavenger activities during exercise