title: Effects of wire-bottom caging on heart rate, activity and body temperature in telemetry-implanted rats.
abstract: Some experimental procedures are associated with placement of animals in wire-bottom cages. The goal of this study was to evaluate stress-related physiological parameters (heart rate [HR], body temperature [BT], locomotor activity [LA], body weight [BW] and food consumption) in rats under two housing conditions, namely in wire-bottom cages and in bedding-bottom cages. Telemetry devices were surgically implanted in male Sprague-Dawley rats. HR, BT and LA were recorded at 5 min intervals. Analysis under each housing condition was performed from 16:00 to 08:00 h of the following day (4 h light, 12 h dark). During almost all of the light phase, the HR of rats housed in wire-bottom cages remained high (371 ± 35 bpm; mean ± SD; n = 6) and was significantly different from that of rats housed in bedding-bottom cages (340 ± 29 bpm; n = 6; P < 0.001; Student's t-test). In general, BT was similar under the two housing conditions. However, when rats were in wire-bottom cages, BT tended to fluctuate more widely during the dark phase. LA decreased when animals were housed in wire-bottom cages, in particular during the dark phase. Moreover, there was a significant difference with respect to the gain in BW: BW of rats housed in bedding-bottom cages increased 12 ± 2 g, whereas that of rats in wire-bottom cages decreased by 2 ± 3 g (P < 0.001). Our results demonstrate that housing rats in wire-bottom cages overnight leads to immediate alterations of HR, BW and LA, which might be related to a stress response.
authors.affiliation: Department of Pharmacology, Unit of Biological Research and Development, Palau Pharma SA, Barcelona, Spain. marta.giral@almirall.com
authors.forename: Marta
authors.initials: M
authors.lastname: Giral
authors.forename: Dolores C
authors.initials: DC
authors.lastname: García-Olmo
authors.forename: Klaas
authors.initials: K
authors.lastname: Kramer
mesh_terms: D000818:Animals; D000830:Animals, Laboratory / Q000502:physiology* / Q000601:surgery; D001831:Body Temperature / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D004435:Eating / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006799:Housing, Animal / Q000592:standards*; D007756:Laboratory Animal Science / Q000592:standards*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D051381:Rats; D013312:Stress, Physiological / Q000502:physiology*; D013686:Telemetry / Q000295:instrumentation