Evidence for a depressive-like state induced by repeated saline injections in Fischer 344 rats.
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.
Izumi
J
J
Central Research Laboratories, Zeria Pharmaceutical Co., Ltd., Saitama, Japan.
Washizuka
M
M
Hayashi-Kuwabara
Y
Y
Yoshinaga
K
K
Tanaka
Y
Y
Ikeda
Y
Y
Kiuchi
Y
Y
Oguchi
K
K
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*
D000929:Antidepressive Agents, Tricyclic; D012965:Sodium Chloride; D007099:Imipramine