[The effect of increased levels of chronic UVB-radiation on the functional state of the body in sheep].

The effect of increased doses of UV-B-radiation produced by LER-40 lamps (with an intensity of 5.5 W/m2 at a daily dose of 20 kJ/m2 and a total dose for 15 days of 300 kJ/m2) on the cardiovascular function, biochemical, biophysical and structural parameters of blood plasma and cells of sheep was investigated. It was found that increased UV-B-radiation produced functional changes in different physiological systems of animals: arrhythmias, diastole shortening, increase of the systole-diastole index; decrease of platelet count, shortening of blood coagulation time; increase of calcium, iron and copper and decrease of zinc in plasma; conformational changes in cytoplasmic membranes of platelets and lymphocytes. The changes that occurred in the sheep at an early stage of exposure can be viewed as adaptive. However, functional changes that were seen at remote stages suggested that the sensitivity of various systems of the body to UV-B-radiation was different.