Effects of chlordimeform on cardiovascular functional parameters: Part 3. Comparison of different routes of administration in the postweanling rat.

The effects of intraperitoneal (ip) administration of chlordimeform (CDM) were investigated in 22- to 24-d-old pentobarbital-anesthetized Sprague-Dawley rats. Animals (n = 32) received a single ip injection of CDM at either 10, 30, or 60 mg/kg, or of normal saline vehicle. Heart rate (HR) and electrocardiogram (ECG) were monitored for all animals, while body temperature was maintained at control levels (37 degrees C). HR decreased 21-29% in the treated animals, and there were no differences observed across dose groups or over time. ECG effects were confined to rate-related changes only. The decrease in HR produced by CDM in these animals was comparable to the delayed HR effect seen in previous studies from this laboratory, despite major differences in dosing regimens and routes of administration.