| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2001: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
In order to evaluate effects of housing conditions on rats and rabbits, we investigated variabilities in physiological parameters. Arterial blood pressure (BP), heart rate (HR) and body temperature (BT) were measured by telemetry in conscious unrestrained animals. Rats were housed in individual plastic cages floored with wood shavings. Rabbits were housed in individual FRP cages floored with stainless steel wire. The experimental room, a light-dark cycle (LD 12:12), was maintained under controlled temperature. The physiological signals were continuously recorded every 5 minutes by a telemetry system. These signals changed with a 24-hour cycle (circadian rhythm) in rats and rabbits. Nocturnal patterns, in which the values in the dark phase were higher than those in the light phase, were observed in rats and rabbits. However, BP and HR in rabbits were lower than those in rats. All animals indicated the rhythms of physiological signals in wide range of room temperature (17-30 degrees centigrade). Male cotton rats showed clear peaks of BT after the light off and on. The difference of dark-light temperature in rabbits was less than in rats. The results suggest that temperature above 28 or below 18 degrees centigrade might produce physiological effects to rats and rabbits. A telemetry system may be useful to evaluate effects of housing conditions on rats and rabbits. Rats and rabbits may adapt to extremes by behavioral, physiologic, and morphologic mechanisms, but such adaptation takes time and might alter experimental outcomes or otherwise affect performance. Thus ventilation in animal room is very important to remove thermal loads caused by animal respiration, lights, and equipment.
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