The effect of sampling technique on pharmacokinetic parameters in rats: A comparison of tradition blood sampling methods with an automated sampler (2001)

Kissinger, C. B., Cregor, M., Hilt, R. et al.

Abstract

The condition of the animal during collection of such fluids [blood, bile, urine, cerebrospinal fluid] may influence metabolism or excretion of the drug. Specifically, conditions that accelerate blood pressure, heart rate and endogenous metabolism can be expected to affect xenobiotic metabolism as well. In this presentation, traditional methods of collecting blood from rats (tail vein, catheters) which involve human contact were compared with a new technique (Culex ABS) which involves neither handling the animal nor human presence during blood collection and which allows the animal to move freely within a [experimental] cage outfitted with food and water ad libitum. ... Blood samples collected manually ... showed levels of stress hormones up to 50 [emphasis added] times higher than blood samples collected automatically without human intervention or presence. ... The correlation between differences in PK [pharmacokinetic] parameters and reduction in the stress hormones supports the use of automated blood sampling as a technique more likely to reflect normal physiology during drug disposition studies in the laboratory rat.