Influence of weight on pulmonary function in the adult guinea pig.
We examined a group of 63 adult female Hartley strain guinea pigs with weight ranging from 625 to 1,200 g in order to ascertain whether pulmonary function tests including lung volumes, pressure-volume curves, and flow-volume curves were affected by the weight of the animal. We found that there was a weight effect on total lung capacity, vital capacity, residual volume, and the forced expiratory flow between 25 and 75% of total lung capacity, although there was no effect on other parameters of airflow. Flow-volume curves for each animal could be accurately fitted to a mathematical equation, and this equation did not vary with the animals' weight. Pressure-volume curves were affected by animal weight, but could be accurately fitted to a weight-corrected equation. We conclude that when pulmonary function tests are performed on adult guinea pigs, lung volumes may be altered in proportion to the weight of the animal. When pressure-volume or flow-volume curves are being considered, although weight can either be corrected for or has no bearing on the shape of the curve, there is a large between-animal variation, and it may be necessary to use large experimental groups when it is impossible to use the same animal as its own control.
Wiggs
B
B
Pulmonary Research Laboratory, St. Paul's Hospital, University of British Columbia, Vancouver, Canada.
Churg
A
A
Wright
J
J
D000818:Animals; D001835:Body Weight; D005540:Forced Expiratory Flow Rates; D005541:Forced Expiratory Volume; D006168:Guinea Pigs; D015656:Respiratory Mechanics; D014109:Total Lung Capacity; D014797:Vital Capacity