Urine from stressed rats increases immobility in receptor rats forced to swim: role of 2-heptanone.
The present study was aimed to determine whether the urine from donor rats, which were physically stressed (UD-PS) by unavoidable electric footshocks, produces despair in receptor partner rats (RP) in the long-term. For each trial, an RP rat was placed during 10 min once per day for 21 days in a small non-movement-restricting cage impregnated with the urine collected from a UD-PS rat. Control rats, free of stimulation, maintained their locomotion and immobility scores at basal values throughout the 21-day test. After 21 days of stressing experience [F(2,90)=15.22, P<0.0001] locomotion significantly increased in RP rats (r=0.938, P<0.01), whereas in the UD-PS group locomotion decreased (r=-0.606, P<0.05). The RP and UD-PS groups displayed the longest time of immobility [F(2,90)=8.83, P<0.001] in the forced-swim test (RP, r=0.886, P<0.05; UD-PS, r=0.962, P<0.001) compared with the control group (r=-0.307, NS). We conclude that the RP became similarly despaired as the UD-PS group through the action of 2-heptanone, a ketonic compound identified in UD-PS urine by HS-GC/MS techniques. This ketone was found to be increased [F(2,15)=3.50, P<0.05] from the 1st day of unavoidable electric footshocks, and to induce despair, an effect reverted [F(2,21)=16.5, P<0.0001] by imipramine (5.0 mg/kg) in another group of rats.
Gutiérrez-García
Ana G
AG
Facultad de Psicología, Universidad Veracruzana, Xalapa, Veracruz, México.
Contreras
Carlos M
CM
Mendoza-López
M Remedios
MR
García-Barradas
Oscar
O
Cruz-Sánchez
J Samuel
JS
D000280:Administration, Inhalation; D000819:Animal Communication; D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D008401:Gas Chromatography-Mass Spectrometry; D007099:Imipramine / Q000494:pharmacology; D007659:Ketones / Q000494:pharmacology* / Q000652:urine*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009812:Odorants; D051381:Rats; D017208:Rats, Wistar; D052617:Solid Phase Microextraction; D013315:Stress, Psychological / Q000652:urine*; D013550:Swimming / Q000523:psychology*
D000929:Antidepressive Agents, Tricyclic; D007659:Ketones; C011917:2-heptanone; D007099:Imipramine