Reciprocal Influence of Sex Steroid Environment and Adipocyte Function in Men

Inclusion Criteria: * Informed consent obtained. * Male subjects * Age 18 - 40 * weight \< 120 kg Exclusion Criteria: * Primary hypogonadism or secondary hypogonadism due to genetic causes (Kallman syndrome etc.), tumors, infiltrative diseases, infections, pituitary apoplexy, trauma, critical illness, chronic systemic illness or intentional. * Treatment with insulin, corticoids, opiates (on a daily basis), androgen- or estrogen analogs or CYP2A6 substrates (Dexmedetomidine, Ifosfamide, Methoxsalen, Miconazole, Tranylcypromine). * Impaired renal function defined as serum-creatine \> 1.5 mg/dL * Impaired liver function, defined as ALAT \> 2.5 times upper limit of normal * Clinically significant active cardiovascular disease including history of myocardial infarction within the past 6 months and/or heart failure (NYHA class III or IV) at the discretion of the investigator * Cancer or any clinically significant disease or disorder, which in the investigator's opinion could interfere with the results of the trial * Palpable prostate nodule or induration, PSA \> 3 ng/mL, prostatism, untreated sleep apnee syndrome, erythrocytosis (hematocrit \> 50%) or hyperviscosity. * Known or suspected abuse of alcohol or narcotics * Mental incapacity, unwillingness, or language barrier precluding adequate understanding or cooperation.