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

Abstract

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 isozymes
is 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 present
study, 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: the
first 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 third
group (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 (p<0.05).