Bile duct cannulation (BDC) studies are usually carried out in the rat to help determine the pharmacokinetic profile (absorption, distribution, metabolism and excretion) of new agrochemicals and pharmaceuticals, which is a regulatory requirement. Following dosing of the drug or chemical, bile is collected from rats at regular intervals, and the bile analysed to determine the level of drug/chemical present.
These studies require that rats have cannulas implanted into their bile ducts to allow for repeated bile collection, potentially over many days. The different aspects of these studies, which include the surgical preparation, dosing and bile collection, can be intricate and/or technically complex. The animals are often kept singly housed following surgical implantation of the cannulas. If insufficient data is generated to meet the study objectives, for example due to inadequate bile collection resulting from blockages in the cannulas, the studies may need to be repeated.
A working group of contract research organisations that routinely carry out BDC studies was brought together by the NC3Rs to share their experiences, and establish the key factors necessary to ensure that these studies are successful and do not need to be repeated. Through these discussions the group has identified opportunities for best practice across various aspects of the studies. The aim of these recommendations is to support all staff involved in conducting BDC studies to maximise the amount of useful data generated using the fewest animals possible, whilst ensuring the highest possible standards of animal welfare. These recommendations have been published in Laboratory Animals.
Peer-reviewed publication: Burden N et al. (2017). Maximizing the success of bile duct cannulation studies in rats: recommendations for best practice. Laboratory Animals 51(5): 457–464. doi:10.1177/0023677217698001