Long-term melatonin treatment reduces ovarian mass and enhances tissue antioxidant defenses during ovulation in the rat

Brazilian Journal of Medical and Biological Research

L.g.a. Chuffa²  J.p.a. Amorim²  G.r. Teixeira¹  L.o. Mendes²  B.a. Fioruci²  P.f.f. Pinheiro¹  F.r.f. Seiva¹  E.l.b. Novelli¹  W. Mello Júnior¹  M. Martinez¹  F.e. Martinez¹ 

[1] ,Universidade Estadual de Campinas Instituto de Biologia Programa de Pós-Graduação em Biologia Celular e EstruturalCampinas SP ,Brasil

关键词: Melatonin;    Ovary mass;    Lipid peroxidation;    Antioxidant defenses;    Superoxide dismutase;   

DOI  :  10.1590/S0100-879X2011007500018

来源: SciELO

【 摘 要 】

Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (± 250-260 g), were randomly divided into two equal groups. The control group received 0.3 mL 0.9% NaCl + 0.04 mL 95% ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 µg·100 g body weight-1·day-1) both intraperitoneally daily for 60 days. All animals were killed by decapitation during the morning estrus at 4:00 am. Body weight gain and body mass index were reduced by melatonin after 10 days of treatment (P < 0.05). Also, a marked loss of appetite was observed with a fall in food intake, energy intake (melatonin 51.41 ± 1.28 vs control 57.35 ± 1.34 kcal/day) and glucose levels (melatonin 80.3 ± 4.49 vs control 103.5 ± 5.47 mg/dL) towards the end of treatment. Melatonin itself and changes in energy balance promoted reductions in ovarian mass (20.2%) and estrous cycle remained extensive (26.7%), arresting at diestrus. Regarding the oxidative profile, lipid hydroperoxide levels decreased after melatonin treatment (6.9%) and total antioxidant substances were enhanced within the ovaries (23.9%). Additionally, melatonin increased superoxide dismutase (21.3%), catalase (23.6%) and glutathione-reductase (14.8%) activities and the reducing power (10.2% GSH/GSSG ratio). We suggest that melatonin alters ovarian mass and estrous cyclicity and protects the ovaries by increasing superoxide dismutase, catalase and glutathione-reductase activities.

【 授权许可】

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