Protein concentration in immunological preparations and pyrogenic reaction of rabbits.

The drop of arterial pressure was found to be caused by proteins injected intravenously into test animals. The drop was related to the protein concentration and the volume of the dose. Low pressure was caused neither by the histamine nor by the protein characterized by its property of liberating histamine. Antihistamines had no influence on quantitative or qualitative depressory reaction, caused by the presence of dissolved proteins. Concentrated protein solutions, when applied intravenously, did not contribute to identifying the pyrogenic reaction, but had a damaging effect on the organism and homeostasis of animals used in the experiments.