[Onset of puberty in boys: comparison between clinical indicators and the changes in the plasma levels of gonadotropic hormones and testosterone]. / Nachalo polovogo sozrevaniia u mal'chikov: sopostavlenie klinicheskikh pokazatelei s dinamikoi urovnia gonadotropnykh gormonov i testosterona v plazme krovi.

The blood plasma LH, FSH and testosterone concentrations were determined in 155 boys aged, 10 to 17 years, by radioimmunoassay. The growth, body weight and puberty degree were detected according to Tanner and the testicular volume by Prader's orchidometer. It was found that hormonal changes in the hypothalamic-hypophyseal-testicular system proceed not parallelly to physical transformations, characteristic of puberty, i.e. hormone concentration rise is seen before the first phenotypical alterations and becomes maximum prior to puberty completion. FSH concentration is 1.67 times as high, reaching the maximum values by the pilar period of the 4th stage and the testicular volume of 8 to 12 ml. LH level is 1.47 times as high, reaching the maximum by the pilar period of the 3d stage and the testicular volume of 8 to 12 ml. Testosterone concentration is 10.47 times as high, reaching the maximum values by the pilar period of the 3d to 6th stage and the testicular volume of 12 to 16 ml. A decrease in the hypothalamic sensitivity to the blood circulating steroids plays a leading role in the puberty pathogenesis.