Mechanisms leading to hypogonadism in men with burns injuries.

A profound and persistent depression of serum testosterone concentrations was found in 19 men with burns injuries. This could not be explained by changes in sex hormone binding globulin capacity, hyperprolactinaemia, classical primary testicular failure, or a hypogonadotrophic state. Pulsatile release of luteinising hormone was found in control subjects but was absent or diminished in burnt patients with low serum testosterone concentrations. In addition, these patients showed reduced biological activity of luteinising hormone as measured by bioassay even though normal concentrations of luteinising hormone were detected by radioimmunoassay. The temporary hypogonadism after burns injury and possibly in other clinical states may be related to hypothalamic dysfunction, which leads to abnormal generation of luteinising hormone releasing hormone and non-pulsatile secretion of luteinising hormone of reduced biological activity.