Oestrone, oestradiol and testosterone in normal and hypogonadal men following LH-RH or HCG stimulation.

oestrone, oestradiol-17beta and testosterone in serum were measured during a LH-RH infusion test and a Leydig cell function test with HCG in healthy men and in patients with primary or secondary hypogonadism. Following infusion of LH-RH increases of LH (+112%), oestradiol (+62%) and testosterone (+51%) were observed in normal men, while oestrone remained unchanged. Of the patients only those with Klinefelter's syndrome showed a significant increase in testosterone and oestradiol after LH-RH infusion. During the Leydig cell function test oestradiol and testosterone exhibited a largely parallel pattern under normal and pathological conditions as well as in subjects with experimental hypogonadism. Augmentations of plasma oestrone were usually smaller than those for oestradiol.