Inhibition of mitochondrial respiratory chain in brain of rats subjected to an experimental model of depression

• Published in: Neurochemistry international Vol. 53; no. 6; pp. 395 - 400
• Main Authors: Rezin, Gislaine T., Cardoso, Mariane R., Gonçalves, Cinara L., Scaini, Giselli, Fraga, Daiane B., Riegel, Rafael E., Comim, Clarissa M., Quevedo, João, Streck, Emilio L.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-12-2008; Elsevier
• Subjects: Adrenal Glands - metabolism; Adrenal Glands - physiopathology; Adrenal Glands - secretion; Animals; Appetite Regulation - physiology; Biological and medical sciences; Biomarkers - analysis; Biomarkers - metabolism; Body Weight - physiology; Brain - anatomy & histology; Brain - metabolism; Brain - physiopathology; Brain Diseases, Metabolic - complications; Brain Diseases, Metabolic - metabolism; Brain Diseases, Metabolic - physiopathology; Chronic Disease; Chronic stress; Creatine kinase; Creatine Kinase - analysis; Creatine Kinase - metabolism; Depression; Depressive Disorder - etiology; Depressive Disorder - metabolism; Depressive Disorder - physiopathology; Disease Models, Animal; Down-Regulation - physiology; Electron Transport - drug effects; Electron Transport - physiology; Energy Metabolism - physiology; Fundamental and applied biological sciences. Psychology; Male; Mitochondria; Mitochondria - drug effects; Mitochondria - metabolism; Organ Size - physiology; Oxidative Phosphorylation; Rats; Rats, Wistar; Respiratory chain; Stress, Psychological - complications; Stress, Psychological - metabolism; Stress, Psychological - physiopathology; Vertebrates: nervous system and sense organs; Depression; Chronic stress; Mitochondria; Respiratory chain; Creatine kinase; Human; Rat; Enzyme; Transferases; Rodentia; Central nervous system; Stress; Encephalon; Vertebrata; Chronic; Mammalia; Animal; Models
• ISSN: 0197-0186; 1872-9754
• DOI: 10.1016/j.neuint.2008.09.012

Depressive disorders, including major depression, are serious and disabling. However, the exact pathophysiology of depression is not clearly understood. Life stressors contribute in some fashion to depression and are an extension of what occurs normally. In this context, chronic stress has been used as an animal model of depression. Based on the hypothesis that metabolism impairment might be involved in the pathophysiology of depression, in the present work we evaluated the activities of mitochondrial respiratory chain complexes and creatine kinase in brain of rats subjected to chronic stress. After 40 days of mild stress, a reduction in sweet food ingestion was observed, as well as increased adrenal gland weight, when compared to control group. We also verified that control group gained weight after 40 days, but stressed group did not. Moreover, our findings showed that complex I, III and IV were inhibited in stress group only in cerebral cortex and cerebellum. On the other hand, complex II and creatine kinase were not affected in stressed group. Although it is difficult to extrapolate our findings to the human condition, the inhibition of mitochondrial respiratory chain by chronic stress may be one mechanism in the pathophysiology of depressive disorders.