Abstract

Hiett, D. M. (1974).British Journal of Industrial Medicine,31, 53-58. Tests of ventilatory function for use in long-term animal studies. Techniques for use in long-term experiments to measure total resistance and total compliance of the guinea-pig ventilatory system are described. The resonance characteristics, required for use of the forced oscillation techniques to determine total resistance, were satisfied by the guinea-pig ventilatory system, and the resonant frequency of these animals was found to be 32 Hz.

The total resistance and total compliance techniques were tested to determine the variability of repeated measurements on individual animals, on groups of animals, and on groups of animals measured over intervals of time. A coefficient of variation of less than 20% was found for repeated measurements on individuals and groups of animals. A gradual increase in total compliance and decrease in total resistance occurred over a period of several weeks when the animals were maturing. Values of 0·13 ml/cmH₂O for total compliance and 0·40 cmH₂O/ml per second for total resistance were found for young guinea-pigs (250-500 g weight), and these are similar to previously reported pulmonary values for similar guinea-pigs.

The value of total measurements of ventilatory function of the complete animal when detecting changes in the lung alone are discussed with respect to guinea-pigs.

The tests are believed to be adequately sensitive and practicable for long-term studies of ventilatory function.