Ethopharmacology of the antidepressant effect of clonazepam in diabetic rats.
Diabetes-associated depression may occur due to changes in the quality of life imposed by treatment, or may be a consequence of the biochemical changes accompanying the disease. It was our objective to evaluate the behaviors of diabetic rats through an animal model of depression, and determine if a positive GABA modulator agent, clonazepam, is an effective antidepressant. Wistar male rats were submitted to the forced-swimming test after 26 days of the induction of diabetes with streptozotocin (60 mg/kg). Test and retest days analyzed with an ethological approach. Clonazepam (control, 0.25, 0. 5, and 1.0 mg/kg) was administered IP 24, 5, and 1 h before the retest. Diabetic rats presented longer immobility duration during test and retest of forced swimming. Diabetic rats dived significantly less during the test. Clonazepam 0.25 and 0.5 mg/kg decreased immobility of diabetic rats with no consequences on the behaviors of nondiabetic rats. These results demonstrate that diabetic rats present more intense depressive-like behavior, such as immobility and lack of interest in exploring the environment, when exposed to the forced-swimming test. It is possible that decreased GABA function is involved in depression associated with diabetes, because a benzodiazepine partially counteracts these changes without modifying blood glucose and glycogen parameters.
Gomez
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R
Division of Pharmacology, Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Sarmento Leite, 245, PC 90050-170, RS, Porto Alegre, Brazil.
Barros
H M
HM
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001786:Blood Glucose / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002998:Clonazepam / Q000494:pharmacology*; D003863:Depression / Q000150:complications* / Q000188:drug therapy* / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000150:complications* / Q000378:metabolism / Q000523:psychology*; D018757:GABA Modulators / Q000494:pharmacology*; D006003:Glycogen / Q000378:metabolism; D008112:Liver Glycogen / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D000928:Antidepressive Agents; D001786:Blood Glucose; D018757:GABA Modulators; D008112:Liver Glycogen; D002998:Clonazepam; D006003:Glycogen