Jacketed telemetry in rats: a novel non-invasive method for cardiorespiratory phenotyping during treadmill exercise

Area of Science:

• Physiology
• Cardiorespiratory Function
• Animal Models

Background:

• Non-invasive monitoring of cardiorespiratory function is crucial for ethical and scientific advancement.
• Existing telemetry tools have limitations, often requiring restraint or surgical implantation, and are not validated for high activity levels.
• A novel jacketed telemetry device was developed for simultaneous monitoring of ECG, respiratory inductive plethysmography, and accelerometry.

Purpose of the Study:

• To evaluate the feasibility and reliability of a non-invasive jacketed telemetry system during a challenging exertion protocol in freely moving rats.
• To assess the device's capability to monitor cardiorespiratory adaptations during incremental treadmill exercise.

Main Methods:

• Male Wistar rats (n=10) were fitted with a jacketed telemetry device.
• An incremental treadmill exercise protocol was employed, with speeds ranging from 5 to 40 cm/s, including 30-second breaks.
• Continuous monitoring of heart rate (HR) and minute ventilation (MV) was performed throughout the protocol and recovery.

Main Results:

• The jacketed telemetry device was successfully worn by rats during the exertion protocol.
• Significant increases in HR and MV were observed at each exercise level and during recovery breaks compared to resting values.
• Cardiorespiratory parameters returned to baseline within 60 minutes post-exercise, indicating reliable monitoring despite mechanical disturbances.

Conclusions:

• The non-invasive jacketed telemetry system is feasible for monitoring cardiorespiratory function in rats during high-activity treadmill exercise.
• This technology enables reliable, non-invasive assessment of cardiorespiratory adaptations in freely moving animals under strenuous conditions.
• The study overcomes previous limitations, allowing for previously unattainable monitoring of cardiorespiratory variables during high activity.