Cerebrospinal Fluid Characterization in Cynomolgus Monkeys, Beagle Dogs, and Göttingen Minipigs.

Intrathecal administration is an important route for drug delivery, and in pharmacology and toxicology studies, cerebrospinal fluid (CSF) collection and analysis is required for evaluating blood-brain barrier penetration and central nervous system exposure. The characteristics of CSF in commonly used nonrodent models are lacking. The purpose of this study is to evaluate and provide some insights into normal cellular and biochemical composition of CSF as well as diffusion potential following intrathecal injection across several nonrodent species.

Incidence of spontaneous arrhythmias in freely moving healthy untreated Sprague-Dawley rats.

Spontaneous arrhythmia characterization in healthy rats can support interpretation when studying novel therapies. Male (n = 55) and female (n = 40) Sprague-Dawley rats with telemetry transmitters for a derivation II ECG. Arrhythmias were assessed from continuous ECG monitoring over a period of 24-48 h, and data analyzed using an automated detection algorithm with 100% manual over-read.