[Modification of endocrinologic parameters by total body UV irradiation]

In 49 healthy test persons we measured various endocrine parameters (ACTH, cortisol, prolactin, triiodothyronine, thyroxine, TSH) prior to and after whole-body irradiation with UV light of varying quality and quantity. 60 min after sunlamp and SUP exposure a marked decrease in the average cortisol plasma level appears which is less than the daily circadian variation. After irradiation with a lamp that mainly emits UVA rays these reactions fail to appear. After sunlamp and SUP irradiation also the concentrations of the thyroid hormones triiodothyronine and thyroxine show a decrease of 22.1 and 13.7%, respectively, which is, however, statistically significant for triiodothyronine only. ACTH and TSH values remain unchanged. According to these results we can conclude that depending on the quality of rays defined endocrinological reactions are caused. Peripheral "consumption" of these hormones and concomitant insufficient central stimulation are suggested.