Daily rhythm of glutathione peroxidase activity, lipid peroxidation and glutathione levels in tissues of pinealectomized rats.
Melatonin is a component of the antioxidant defense system since it has radical scavenging and antioxidant activities. In the present study, we aimed to investigate the endogenous rhythm of antioxidant enzyme glutathione peroxidase (GSH-Px) activity, oxidized glutathione (GSSG) and lipid peroxidation levels in tissues of pinealectomized rats (PINX). Rats were sacrificed by decapitation at 4 h intervals. GSH-Px activity, GSSG and lipid peroxidation levels showed a daily rhythm both in controls and in PINX rats. GSH-Px and GSSG exhibited the peak levels after the peak time of melatonin which was determined previously by other groups. Lipid peroxidation levels increased progressively during the night and started to decline before the GSH-Px peak time. These findings suggest that endogenous melatonin is involved in the night time increase of GSH-Px activity and GSSG levels and modulates the daily rhythm pattern of GSH-Px. In conclusion, pinealectomy which eliminates the melatonin rhythm has a supressor effect on GSH-Px activity levels.
Baydas
Giyasettin
G
Department of Physiology, College of Medicine, Firat University, Elazig 213119, Turkey. baydas@hotmail.com
Gursu
M Ferit
MF
Yilmaz
Seval
S
Canpolat
Sinan
S
Yasar
Abdullah
A
Cikim
Gurkan
G
Canatan
Halit
H
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D002940:Circadian Rhythm / Q000502:physiology*; D003714:Denervation; D016166:Free Radical Scavengers / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D015227:Lipid Peroxidation / Q000502:physiology; D008099:Liver / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008550:Melatonin / Q000172:deficiency*; D018384:Oxidative Stress / Q000502:physiology*; D010870:Pineal Gland / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D016166:Free Radical Scavengers; D008315:Malondialdehyde; D002374:Catalase; D005979:Glutathione Peroxidase; D005978:Glutathione; D008550:Melatonin