Effects of adenosine triphosphate on methanol-induced experimental optic nerve damage in rats: biochemical and histopathological evaluation

Abstract

Purpose: Acute methanol exposure leads to systemic intoxication and toxic optic neuropathy. In this experimental study, we aimed to determine the protective effects of intravenous administration of ATP in methanol-induced optic neuropathy.

Materials and methods: A total of 18 male albino Wistar rats weighing between 267 and 282 g were used for the experiment. The animals were divided into three groups as healthy control (HC), methanol (M), and methanol + ATP (M-ATP) groups. Distilled water was given to the healthy control group (n = 6) as the solvent, while 20% methanol was administered orally to the rats in M (n = 6) and M-ATP (n = 6) groups at a dose of 3 g/kg. Four hours after the administration of 20% methanol orally to the M-ATP group, ATP was injected intraperitoneally at a dose of 4 mg/kg. Eight hours after ATP injection, the animals were sacrificed by high-dose (50 mg/kg) thiopental anaesthesia and biochemical and histopathological examinations were performed on the removed optic nerve tissues. Malondialdehyde (MDA), total glutathione (tGSH), total oxidant status (TOS) and total anti-oxidant status (TAS) were analysed with biochemical tests.

Results: MDA, TOS and OSI were significantly higher and tGSH and TAS levels were significantly lower in methanol administered group compared with the healthy controls or M-ATP group (p: 0.001). There was not any significant difference between healthy controls and M-ATP group regarding the oxidative stress parameters. There was a significant destruction and increase in thickness and astrocyte numbers and edema-vacuolization in methanol administered group compared with the healthy controls or M-ATP group (p: 0.001).

Conclusion: Intravenous ATP administration had a significant positive effect on the oxidative stress parameters and optic nerve structure in methanol-intoxicated rats. Antioxidant therapies should be considered in future studies as a possible therapy for methanol-induced toxic optic neuropathy.

Keywords: Adenosine triphosphate; methanol; optic nerve; oxidative stress; rats.