Validation of the use of nonnaive surgically catheterized rats for pharmacokinetics studies.

Although large animals, such as dogs and nonhuman primates, often are used for more than 1 pharmacokinetics study, common practice is to use only naive rodents for pharmacokinetics studies. We undertook a series of studies to validate whether surgically cannulated nonnaive rats could be used again after a 7-d washout. When vascular catheters are cared for appropriately, we find that they remain patent for more than 2 wk, with negligible drug carryover.