title: Protective effect of hydrocortisone on iminodipropionitrile-induced neurotoxicity in rats.
abstract: Occupational and environmental exposure of synthetic nitriles is of potential relevance to human health. Iminodipropionitrile (IDPN), a prototype nitrile toxin, has been shown to produce dyskinetic syndrome in rodents. This study reports the effect of concomitant exposure of rats to hydrocortisone and IDPN on behavioural abnormalities namely excitation, circling and chorea (ECC) syndrome. Four groups of female Wistar rats were given hydrocortisone (0, 10, 30 and 60 mg/kg, gavage, for 10 days) 30 min. before IDPN (100 mg/kg, intraperitoneally for 8 days). Two additional groups of rats were treated with either saline (control group) or 60 mg/kg of hydrocortisone (drug alone group). The animals were observed for neurobehavioural abnormalities including dyskinetic head movement, circling, tail hanging, air righting reflex and contact inhibition of righting reflex. After behavioural studies, the animals were killed, and the discrete brain regions and temporal bones were collected for biochemistry and inner ear histopathology, respectively. Hydrocortisone significantly and dose dependently attenuated the incidence and severity of IDPN-induced behavioural syndrome. Administration of hydrocortisone (60 mg/kg) alone significantly increased glutathione (GSH) levels in olfactory bulb and striatum, whereas IDPN alone significantly reduced GSH levels in olfactory bulb, striatum and hippocampus. Hydrocortisone (60 mg/kg) significantly compensated IDPN-induced depletions of GSH in different brain regions. Hydrocortisone also protected the animals against IDPN-induced vestibular hair cell degeneration. The protective effect of hydrocortisone may be attributed to its anti-inflammatory and antioxidant properties.
authors.affiliation: Neuroscience Research Group, Armed Forces Hospital, Riyadh, Saudi Arabia. rkh_research@yahoo.com
authors.forename: Mohammad
authors.initials: M
authors.lastname: Tariq
authors.forename: Haseeb Ahmad
authors.initials: HA
authors.lastname: Khan
authors.forename: Mairaj M
authors.initials: MM
authors.lastname: Siddiquei
authors.forename: Khalaf
authors.initials: K
authors.lastname: Al Moutaery
authors.forename: Saleh
authors.initials: S
authors.lastname: Al Deeb
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004409:Dyskinesia, Drug-Induced / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D005978:Glutathione / Q000187:drug effects / Q000378:metabolism; D018069:Hair Cells, Vestibular / Q000187:drug effects / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D006854:Hydrocortisone / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D009498:Neurotoxins / Q000633:toxicity; D009570:Nitriles / Q000633:toxicity; D009830:Olfactory Bulb / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000893:Anti-Inflammatory Agents; D009498:Neurotoxins; D009570:Nitriles; C008110:3,3'-iminodipropionitrile; D005978:Glutathione; D006854:Hydrocortisone