Effect of ultraviolet radiation and kinins on oxygen uptake by tissue slices and on basal metabolism in rabbits.

The experiments were carried out on 85 rabbits in 15 groups of 5-8 animals in each. The different groups received: 1) ultraviolet radiation once during 45 minutes or daily during 10 minutes for 6 weeks, 2) bradykinin intravenously 10 microgram/kg, 3) kallikrein 5 B.U./kg intramuscularly during 3 weeks. The levels of kinins and kininogen, and the activity of kallikrein and kininases were determined in the blood several times during 24 hours after radiation exposure, and at intervals of two weeks during long-term exposure to radiation. In the same time periods after exposure the basal metabolism and the uptake of oxygen by slices of the kidneys, liver, heart and skin in vitro were determined. Determinations of aerobic metabolism were carried out also after bradykinin injection and at weekly intervals during kallikrein administration. It was found that: 1) after exposure to ultraviolet radiation there was a high rise in the level of kinins and a fall of kininogen, the activity of kininogenases was raised and that of kininases was decreased, while oxygen uptake was reduced moderately; 2) exogenous bradykinin and endogenous kinins reduced oxygen uptake in vivo and in vitro.