title: Melatonin attenuates the effects of sub-acute administration of lead on kidneys in rats without altering the lead-induced reduction in nitric oxide.
abstract: Exposure to lead induces oxidative stress and renal damage. Although most forms of oxidative stress are characterized by simultaneous elevation of nitrogen and oxidative species, lead-induced oxidative stress is unusual in that it is associated with a reduction in nitric oxide (NO) levels in the kidney. The role of NO in kidney injury is controversial; some studies suggest that it is associated with renal injury, whereas others show that it exerts protective effects. Concentration-dependent effects have also been proposed, linking low levels with vasodilatation and high levels with toxicity. The aim of this study was to evaluate the effects of melatonin co-exposure on the lead-induced reduction in renal NO levels. We found that sub-acute intraperitoneal administration of 10 mg/kg/day of lead for 15 days induced toxic levels of lead in the blood and caused renal toxicity (pathological and functional). Under our experimental conditions, lead induced an increase in lipid peroxidation and a decrease in NO. Melatonin co-treatment decreased lead-induced oxidative stress (peroxidation level) and toxic effects on kidneys without altering the lead-induced reduction in renal NO. These results suggest that, in our experimental model, the reduction in renal NO levels by lead exposure is not the only responsible factor for lead-induced kidney damage.
authors.affiliation: Departamento de Farmacia, Universidad de Guanajuato, Noria Alta, Guanajuato 36050, Mexico. Electronic address: alfarominerva@yahoo.fr.
authors.forename: Minerva
authors.initials: M
authors.lastname: Martínez-Alfaro
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Ramírez-García
authors.forename: Silvia
authors.initials: S
authors.lastname: Gutiérrez-Granados
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Alcaraz-Contreras
authors.forename: Marco-Alonso
authors.initials: MA
authors.lastname: Gallegos-Corona
authors.forename: G Zaldivar Lelo
authors.initials: GZ
authors.lastname: de Larrea
authors.forename: Alfonso
authors.initials: A
authors.lastname: Cárabez-Trejo
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D007274:Injections, Intraperitoneal; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008550:Melatonin / Q000008:administration & dosage / Q000494:pharmacology*; D009569:Nitric Oxide / Q000737:chemistry* / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D009942:Organometallic Compounds / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000097:blood / Q000633:toxicity; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D009942:Organometallic Compounds; D009569:Nitric Oxide; D008550:Melatonin; C008261:lead acetate
keywords: Lead acetate; Melatonin; Nitric oxide