European Journal of Anatomy

Official Journal of The Spanish Society of Anatomy
Cover Volume 4 - Number 1
Eur J Anat, 4 (1): 53-60 (2000)

Ideal transpulmonary pressure for excised lungs. Morphometric study of the rat

De Dios Escolar J., Tejero C., Escolar M.A., Garisa R., Roques M.

Depto. de Ciencias Morfologicas, Facultad de Medicina, Universidad de Zaragoza, C/ Domingo Miral s/n, 50009 Zaragoza, Spain

ABSTRACT We carried out this study to propose a transpulmonary pressure (TPP) which will permit the utmost fixation of a lung in which artefacts are produced. 80 rats were used divided into two age groups: adults and older animals. These groups were then organised into four sub-groups according to the TPP used for the fixation: 20, 25, 30, and 35 cm H2O They were fixed by airway with formalin at 10% Lung volume was measured and a descriptive histological and morphometric study was made. The results obtained in the adult animals reveal a direct relation with the TPP. As the TPP was elevated, the pulmonary aerial volume and the internal alveolar surface increased significantly in the lungs fixed at 25, 30, and 35 cm H2O cm as compared to those fixed at 20 H2O. The alveolar cord diminished significantly in the three groups fixed at the higher pressure as compared with that of the 20 cm H2O group. The number of alveoli and the tissue volume increased significantly when the TPP was raised from 20 to 30 cm H2O and from 30 to 35 cm H2O. Only the older animals showed significant differences in the alveolar cord when the TPP was raised from 20 to 25 cm H2O. We propose that in the adult animals the TPP of 25 cm H2O is the most adequate for king fixation; the TPP of 35 cm H2O is that which most distended the lung. However, the increase in tissue volume suggests the possibility that tissue edema has occurred. In the lungs of older animals, the slight differences found suggest that any of the TPP utilised may be used since the lungs were barely modified by them.

Keywords: airway, animal experiment, animal tissue, article, artifact, controlled study, exercise, lung alveolus, lung edema, lung pressure, lung volume, morphometrics, nonhuman, rat, tissue fixation, total lung capacity

European Journal of anatomy
ISSN 2340-311X (Online)