title: Evidence for a depressive-like state induced by repeated saline injections in Fischer 344 rats.
abstract: We investigated the behavioral changes induced by mild stress in animals that may be relatively susceptible to a depressive-like state, the Fischer 344 rat strain. The mild stress of repeated handling and intraperitoneal (i.p.) injections with saline (2 ml/kg, twice a day for 14 days) elicited a moderate suppression of body weight gain, a decrease in open field activity, and a prolonged immobility during the tail suspension test in Fischer 344 rats compared with Sprague-Dawley rats. Chronic treatment of Fischer 344 rats with imipramine (10 mg/kg i.p., twice a day for 14 days) effectively suppressed open field activity and prolonged immobility. These results suggest that repeated saline injections may be a mild stressor in these rats. In the Fischer 344 strain, which may be vulnerable to the effects of mild stressors, repeated saline injections might induce a depressive-like state and could presumably represent an experimental model for depression.
authors.affiliation: Central Research Laboratories, Zeria Pharmaceutical Co., Ltd., Saitama, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Izumi
authors.forename: M
authors.initials: M
authors.lastname: Washizuka
authors.forename: Y
authors.initials: Y
authors.lastname: Hayashi-Kuwabara
authors.forename: K
authors.initials: K
authors.lastname: Yoshinaga
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Y
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Y
authors.initials: Y
authors.lastname: Kiuchi
authors.forename: K
authors.initials: K
authors.lastname: Oguchi
mesh_terms: D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology; D001835:Body Weight; D003866:Depressive Disorder / Q000139:chemically induced* / Q000503:physiopathology / Q000523:psychology; D004644:Emotions / Q000502:physiology; D006234:Handling, Psychological; D019417:Hindlimb Suspension; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000502:physiology; D051381:Rats; D011916:Rats, Inbred F344; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000633:toxicity*
chemical_list: D000929:Antidepressive Agents, Tricyclic; D012965:Sodium Chloride; D007099:Imipramine