Effects of Growth Hormone and IGF-1 on Anabolic Signals and Stem Cell Recruitment in Human Skeletal Muscle

12 adult hypopituitary patients with newly diagnosed Growth hormone (GH)-deficiency will be studied two times. The first examinations will be performed shortly after time of diagnose before initiation of exogenous GH treatment, where each subject will receive a single intravenous bolus of 0.5 mg GH. The examination day will be repeated after prolonged GH replacement therapy (\>3 month after treatment initiation).