THE USE OF TELEMETRY TO RECORD ELECTROCARDIOGRAM AND HEART-RATE IN FREELY SWIMMING RATS

Measurement of parameters from the circulatory system of laboratory an imals can play an important role in pharmacological or toxicological r esearch. To study the mutual interaction between physical exercise and antioxidant systems in rats, we selected swimming as a model for exer cise performance. Swimming belongs to the natural behavior of the rat, and under proper experimental conditions, it primarily involves physi cal exercise with little emotional arousal. Therefore, we developed a swimming basin in which the intensity of exercise could be manipulated through speed and duration of swimming. A laser beam interruption sys tem enables the rat to be followed during each swimming session. A mot or-controlled following device, consisting of a rail and sledge connec ted to a position sensor, contains an antenna mounted in a receiver bo ard. In this way, we can record the electrocardiogram (ECG) and heart rate (HR) with a commercially available telemetry transmitter implante d in the peritoneal cavity of freely swimming mts and evaluate the phy sical fitness (condition) of the the swim-trained rats.