INFLUENCE OF LONG-TERM EXPOSURE TO ADVERSE ENVIRONMENTS ON ORGAN WEIGHTS AND HISTOLOGY

摘要

A comparison was made of the morphologic effects of cold, heat, and simulated altitude on adult male tats given exposures of 24 weeks' duration. By the use of co-variance analysis it was possible to determine the extent to which organ weights were dependent on body weight and to adjust the values in order to remove influences of body weight. For liver, heart, and kidney, adjusted weights indicated temperature-dependency, while pressure-dependency was established for liver and kidney only. Histologically, temperature-dependency was indicated for liver, kidney, thyroid, adrenal, and pituitary. Fur weight was reduced in hear but not altered in cold. Fasting in cold induced changes in adrenal and thymus weight and unusually high body weight loss; in heat, fasting caused a significant thymus weight loss without adrenal weight increase. The thymus-adrenal ratio was elevated during a 24-hour fast in all environments except cold, where it was decreased.