The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.

The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.

No previous work on the toxicity of increased oxygen tensions in the respired air has been conducted under conditions in which all other factors were constantly and perfectly controlled, and most of the investigations upon this subject have been based upon data obtained from observing a limited number of animals. The possession of a large chamber, susceptible to accurate and steady adjustment, has made it possible to carry out decisive experiments on large groups of animals. The first project to which this new apparatus has been devoted consisted of observations on the life history of a standard laboratory animal living for prolonged periods in an environment normal in all respects except for the increase in the oxygen tension of the air. It was our intention to determine whether or not any acclimatization could be produced against the toxic action upon the lungs of high oxygen tensions and, if so, what changes in the animal were responsible for this adaptation. The data we have accumulated deal with a single species, the standard albino rat, bred from Wistar Institute stock, exposed to compressed air having an oxygen tension of 635 ram. of mercury equivalent to 83.6 per cent oxygen at normal barometric pressure.

Previous papers (1, 2) have described the apparatus and technique used by the authors in prolonged experiments upon the effects of high oxygen tensions on rats. The structural changes produced in the lungs of animals living in an environment having a high oxygen tension, particularly those accompanying long exposure, have never been thoroughly observed, nor has the effect of age received any appreciable comment. Our observations have shown that rats under 1 month of age do not give clinical evidence of suffering the acute pulmonary effects of 83.6 per cent oxygen; that these effects appear with advancing age; that older animals surviving acute oxygen poisoning are immune on second exposure. In this paper we describe structural differences in the lungs of young and old rats; differences in the effects of 80 per cent oxygen on animals of various ages; and finally the structural changes found in the lungs of rats which have become resistant to the acute effects of toxic concentrations of oxygen. Autopsies and Pathological Technique244 albino rats were observed during this study. 137 autopsies were performed, 21 of which were upon normal animals to serve as controls. All dead and dying animals were removed for autopsy as soon as possible. In addition to these, live animals were removed every day during the first 8 days of exposure, and at weekly or biweekly intervals after that. Live rats were killed with an intraperitoneal injection of 0.5 to 1.0 cc. of 1 per cent potassium cyanide. The lungs were removed and fixed in Zenker's fluid for 24 hours. Hematoxylin and eosin stain was used

The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.