Effects of chlordimeform on cardiovascular functional parameters: Part 2. Acute and delayed effects following intravenous administration in the postweanling rat.

The effects of intravenous (iv) administration of chlordimeform (CDM) were investigated in 22- to 30-d-old pentobarbital-anesthetized Sprague-Dawley rats. Animals (n = 25) were given sequential iv injections of 5, 10, 30, 60, and 120 mg CDM/kg, or normal saline vehicle followed by a single injection of 60 mg CDM/kg. Heart rate (HR), arterial blood pressure (BP), and electrocardiogram (ECG) were monitored for all animals, while body temperature was maintained at control levels (37 degrees C). CDM produced profound acute effects on all cardiovascular parameters monitored and persistent delayed effects on HR and BP. These effects were similar to but less severe than those observed in a previous study using geriatric animals. Younger animals also appeared to be more resistant to the lethal actions of CDM.