Unchanged response to stimulation of pituitary hormone release after serial UV irradiation in men

A group of 24 healthy young men were evaluated before and after serial suberythematous ultraviolet (UV) radiation: group I, control (no irradiation); groups II and III, 12 radiations in 4 weeks with two different spectra (both containing UV-B). Before the first and 2 days after the last exposure all the volunteers were given an intravenous injection of thyrotropin releasing hormone (TRH, protirelin 0.2 mg) and luteinizing hormone releasing hormone (LH-RH, gonadorelin 0.1 mg). The serum concentrations of TSH, follicle stimulating hormone, LH and prolactin were measured at 0, 20, 30, 45 and 60 min by radioimmunoassay. Neither basal nor stimulated levels of the pituitary hormones showed significant changes after UV radiation. The results showed that exposure to suberythematous doses of UV did not influence the regulation of pituitary hormones in these healthy individuals.