Hyperbaric whole-body plethysmograph for rodents.

Area of Science:

• Physiological measurement systems
• Respiratory physiology research
• Animal model studies

Background:

• Accurate measurement of respiratory variables is crucial for physiological research.
• Existing whole-body plethysmographs may have limitations under hyperbaric conditions.
• Adaptable systems are needed for comprehensive respiratory gas analysis.

Purpose of the Study:

• To describe the design and calibration of a novel rodent whole-body plethysmograph.
• To evaluate its performance under normobaric and hyperbaric conditions.
• To assess its adaptability for measuring oxygen consumption and CO2 production.

Main Methods:

• Construction of a dual-cylinder Plexiglas plethysmograph with controlled temperature and gas preconditioning.
• Dynamic and static calibration procedures to assess system linearity and response.
• Testing under normobaric (1 ATA) and hyperbaric conditions.

Main Results:

• The plethysmograph demonstrated uniform system response (60-270 cycles/min) and linear correlations during static calibration.
• Linear correlation between transducer output and calibration volume was maintained under hyperbaric conditions.
• Respiratory variables measured were comparable to literature values; system adaptable for O2 consumption and CO2 production.

Conclusions:

• The described rodent whole-body plethysmograph is a reliable tool for respiratory measurements under various pressures.
• Adaptability for gas exchange measurements is feasible, with specific considerations for steady-state, CO2 accumulation, and gas concentration changes.
• This system offers a valuable platform for advanced respiratory physiology research in rodents.