Effects of cage enrichment on heart rate, blood pressure, and activity of female Sprague-Dawley and spontaneously hypertensive rats at rest and after acute challenges.

Here we sought to determine whether a nonsocial cage enrichment program, identical to one we previously used with male rats, was effective in reducing heart rate or systolic blood pressure (SBP) in female Sprague-Dawley rats and spontaneously hypertensive rats (SHR). Young adult rats, each instrumented with a radiotelemetry pressure transmitter, were housed individually under enriched or nonenriched conditions. Heart rate and SBP were monitored at 5- and 1-min intervals, respectively, when the rats were undisturbed or after several different types of experimental manipulations some of which are considered stressful.

Effect of housing rats in dim light or long nights on heart rate.

Housing laboratory animals under lighting conditions that more closely mimic the natural environment may improve their wellbeing. This study examined the effects of dim light or a long-night photocycle on resting heart rate (HR) of rats and their HR responses to acute procedures. Male and female Sprague-Dawley (SD) and spontaneously hypertensive (SHR) rats, instrumented with radiotelemetry transmitters and housed individually under a 12:12-h light:dark photocycle with 10 lx illumination (dim light) or under an 8:16-h light:dark photocycle with 200 lx illumination (long nights), were compared with control rats individually housed under a 12:12-h light:dark photocycle with 200 lx illumination.

Stress-like responses to common procedures in rats: effect of the estrous cycle.

The objective of this study was to assess cardiovascular and behavioral responses of Sprague-Dawley female rats subjected to or witnessing common husbandry and experimental procedures at various points during the estrous cycle. Heart rate (HR) and mean arterial blood pressure (MAP) were determined using radiotelemetry for 2 h before and 3 h after: cage change, restraint and subcutaneous (s.c.

Stress-like responses to common procedures in male rats housed alone or with other rats.

The objective of this study was to assess the cardiovascular function and behavior of male Sprague-Dawley rats housed individually or with one or three cagemates during resting conditions and when subjected to common husbandry and experimental procedures and potentially stressful olfactory stimuli. Heart rate (HR), mean arterial blood pressure (MAP), and movement in the cage were collected by using radiotelemetry for 24 h on an experiment-free day and for 2 h before and 3 h after the following acute procedures: cage change, restraint and subcutaneous injection, restraint and tail-vein injection, exposure to the odor of urine and feces from stressed rats, and exposure to the odor of dried rat blood. Home cage behaviors (sleeping, awake, moving, rearing, and grooming) were scored once each minute for 15 min before and 45 min after the acute procedures.