Growth hormone infusions tested for immune boost in healthy men

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

* INCLUSION CRITERIA: 1. Healthy men only (There is a gender difference in GH response with adult females requiring on average twice the GH dose for similar effects. In order to eliminate gender difference as a confounding factor in this study, we are studying male subjects only because the GH dose requirement is lower.) 2. Age 25-50 (Age restriction is used to remove age as a confounding factor because GH and thymic function are known to decrease with age.) 3. Screening laboratory evaluations with no clinically significant abnormal results (minor deviations from "normal" lab results will be at the discretion of the principal investigator): 1. fasting comprehensive metabolic panel 2. complete blood count with differential and platelets 3. 75-gram oral glucose tolerance test (OGTT) * fasting plasma glucose (FPG) \< 100 mg/dL * 2-hr OGTT \< 140 mg/dL 4. Insulin-like growth factor-I (IGF-I) 5. thyroid function test (TSH, free T3, free T4) 6. fasting lipid profile 4. BMI \< 30 (Men with BMI \>= 30 are excluded because decrease in GH secretion and clearance has been shown in obesity.) 5. Have NOT participated in another clinical trial involving any pharmacologic agents within the past 60 days 6. Able to complete an inform consent 7. Agree to not participate in other clinical trials within the study period EXCLUSION CRITERIA: 1. Women 2. FPG \>= 100 mg/dL or 2-hour OGTT \>= 140 mg/dL 3. Abnormal electrocardiogram (EKG) suggesting possible underlying cardiac conditions that, in the opinion of the investigator(s), may cause participation of the subject in the study unsafe 4. Positive stool guaiac 5. Evidence of illicit drug use 6. History of smoking any tobacco products within one year prior to screening 7. Alcohol intake \> 30 grams (drink more than 2 beers per day OR equivalent amount of alcohol) 8. History of Human Immunodeficiency Virus (HIV) infection 9. History of active or chronic Hepatitis B and/or C infection 10. History of malignancy 11. History of coronary disease 12. History of seizures or other neurologic diseases 13. History of liver or renal diseases 14. History of gastrointestinal or endocrine disorders 15. History of glucocorticoid use (over one month) or other immunosuppressive agents (any) 16. unable to undergo a magnetic resonance imaging (MRI) procedure 17. Any medical history that, in the opinion of the investigator(s), will make participation of the subject in the study unsafe