New model for intravenous drug administration and blood sampling in the awake rat, designed to increase quality and throughput for in vivo pharmacokinetic analysis.

Introduction: There is a continuing need for increased throughput in the examination of new chemical entities (NCEs) in terms of the pharmacokinetic (PK) parameters. The aim was to validate a new study method designed to improve throughput and reduce inter-animal variability and animal number requirement in routine bioavailability and plasma PK studies of NCEs in awake rats.

Methods: The design uses a new method for intravenous (iv) administration via the saphenous vein in combination with serial blood sampling via the tail vein.

Method for the determination of the levels of beta-amyloid peptide in the CSF sampled from freely moving rats.

Introduction: In the present study, a model was developed to determine the effect of secretase inhibition on beta-amyloid peptide (Abeta) levels in the cerebrospinal fluid (CSF) of freely moving adult rats.

Methods: Rats were chronically implanted with a cannula into the cisterna magna and CSF samples were collected at different time points from the same animal without anaesthesia. The levels of CSF Abeta were measured by a sandwich ELISA assay.