Feasible model for locoregional and systemic longterm administration of drugs and concomitant blood sampling in Sprague-Dawley rats.

This methodological study describes three surgical procedures for locoregional and systemic drug administration, which are based on a similar experimental design. Cannulation of the arterial and portal access to the liver in comparison to the general venous system, and arterial access to the large intestine through a permanently implantable system, suitable for serial bolus injections and infusions in unrestrained rats, is presented (experiment I). Furthermore, an infusion system for longterm administration (experiment II) and a method for blood sampling during locoregional or systemic infusion procedures (experiment III) have been developed. The positioning and free flow of the catheters were checked by means of scintigraphy, administration of fluorescein under UV light and angiography in animals of experimental series I. After 7 days, no obstruction was detected. On day 15 and 30 following implantation 73.3% and 58.3% of the animals, respectively, showed unimpeded flow through the catheter system. The methods described here were well tolerated by the animals without alteration of their general condition and are currently in use in a series of chemotherapeutic and pharmacokinetic investigations.