Search

Background: The objective was to determine the antioxidant role of L-carnitine (LC) against ionizing radiation-induced cataracts in lens after total cranium irradiation of rats with a single dose of 5 Gy., Methods: Sprague-Dawley rats were used in this experiment and were divided into three groups. Group 1 did not receive LC or irradiation (control group). Group 2 received a 5 Gy gamma irradiation as a single dose to the total cranium (RT group). Group 3 received total cranium irradiation plus 100 mg/kg body weight/day LC (RT+LC group). The rats were irradiated using a cobalt-60 teletherapy unit. At the end of the 10th day, the rats were sacrificed and their eyes were enucleated. The lenticular activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were measured. Furthermore, the lenticular content of an indicator of lipid peroxidation, malondialdehyde (MDA), was measured., Results: Irradiation significantly increased the MDA level as an end product of lipid peroxidation. Irradiation also significantly decreased SOD activity and increased GSH-Px activity, indicating the generation of oxidative stress and an early protective response to oxidative damage. Irradiation with 5 Gy to the total cranium as a single fraction formed cataracts in the rat lenses. Cataract development was detectable in 9 rats in the RT group, and in only 4 rats in the RT+LC group 10 days after irradiation. LC administration plus irradiation significantly decreased the MDA level and increased the activity of SOD and GSH-Px enzymes, which might indicate the protection of the lenses from gamma radiation-induced cataracts., Conclusions: L-carnitine may protect against the damage produced by gamma radiation by increasing the activity of the SOD enzyme and by scavenging free radicals generated by ionizing radiation. As a result of this process, MDA as an indicator of lipid peroxidation may decrease.

Purpose: To investigate the efficacy of L-carnitine in preventing retinal injury followed by ischemia-reperfusion., Methods: The eyes of 34 guinea pigs were used in this experiment. The guinea pigs were divided into two groups: the first group (n=17) was given L-carnitine intraperitoneally (500 mg/kg) and second group (n=17) received the same dose of saline solution. Under general anesthesia, peritomy was performed. Retro-orbital tissues were ligated for 90 minutes and ischemia was induced, followed by 4 hours of reperfusion. One of the enucleated eye was stained with hematoxylin and eosin (H&E) and retinal thicknesses were evaluated. Thiobarbituric acid reactive substances (TBARS) levels were determined in the retina of the other eye., Results: Mean TBARS levels in retinal tissue were found lower in L-carnitine group (2.77 +/- 0.55 microM) than in the control group (6.57 +/- 1.19 microM), (p<0.01). On the other hand, mean retinal thickness was found to be increased in the control group (47.47 +/- 5.62 microm) when compared to the L-carnitine group (26.52 +/- 4.65 microm), (p<0.01). In correlation analysis, significantly positive relationships were found between retinal TBARS level and retinal thickness both in the control and L-carnitine groups (r=0.981, p<0.01 and r= 0.967, p<0.01 respectively)., Conclusions: L-carnitine is effective in preventing retinal injury followed by ischemia-reperfusion.