Weekend versus working day: differences in telemetric blood pressure in male Wistar rats (2007)

Schreuder, M. F., Fodor, M., van Wijk, J. A. E. et al.

Abstract

We retrospectively compared Blood Pressure values in adult male Wistar rats during working hours with values from non-working days, using telemetry. Values were obtained at the age of 6 and 12 months during working hours (Friday 10:00-16:00 h, lights on 06:00-18:00 h) and compared with data from the average of Saturday 10:00-16:00 h and Sunday 10:00-16:00 h, representing non-working days.Data were available from 12 and 7 rats at 6 months and 12 months of age respectively. Relative differences in heart rate, spontaneous locomotor activity, systolic and diastolic BP were 2.2% (P<0.001), 32.9% (P<0.05), 3.2% (P<0.05) and 3.7% (P<0.05), respectively, with no differences between the age groups.We have shown a significant and important difference between BP values obtained during working hours and non-working days using telemetry in adult male Wistar rats. This phenomenon has implications for the interpretation of BP measurements in animals.