title: Efficacy of melatonin as protectant against oxidative stress and structural changes in liver tissue in pinealectomized rats.
abstract: Previous observations demonstrated that physiological levels of melatonin, the pineal secretory product, are important in protecting against oxidative stress-induced tissue damage. We investigated the effects of pinealectomy and administration of exogenous melatonin on liver tissue in rats. Pinealectomized (Px) and sham-operated (non-Px) rats were used. We evaluated structural changes, reduced glutathione (GSH) levels and malondialdehyde (MDA) levels. Rats were divided into three groups (10 rats in each group): control (non-Px), Px+vehicle and Px+melatonin (4 mg/kg given daily intraperitoneally for 10 days). Liver GSH levels were significantly lower in Px rats than in the control group. Melatonin administration significantly increased GSH levels (p < 0.05). Px caused a significant increase in MDA levels as compared with the control group and melatonin administration to Px rats significantly reduced MDA levels in the liver (p < 0.05). Sinusoidal dilatation to a varying degree developed in all Px rats. Severity of mononuclear cell infiltration and sinusoidal congestion were lower in Px+melatonin group than in the Px group. These findings suggest that a significant increase in oxidative and structural changes occur in rat livers after pinealectomy, which can be diminished by melatonin treatment.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Firat University, Elazig, Turkey. esahna@hotmail.com
authors.forename: Engin
authors.initials: E
authors.lastname: Sahna
authors.forename: Hakan
authors.initials: H
authors.lastname: Parlakpinar
authors.forename: Nigar
authors.initials: N
authors.lastname: Vardi
authors.forename: Yilmaz
authors.initials: Y
authors.lastname: Ciğremis
authors.forename: Ahmet
authors.initials: A
authors.lastname: Acet
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism; D007274:Injections, Intraperitoneal; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000473:pathology; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008550:Melatonin / Q000008:administration & dosage / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D010870:Pineal Gland / Q000187:drug effects* / Q000378:metabolism / Q000601:surgery; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D008315:Malondialdehyde; D005978:Glutathione; D008550:Melatonin