OBJECTIVES: I. Determine whether release of endogenous growth hormone (GH)-releasing hormone is involved in GH responses to clonidine, pyridostigmine, levodopa, arginine, GH-releasing peptide, insulin-induced hypoglycemia, and exercise in patients with acromegaly.

II. Determine whether endogenous GH-releasing hormone influences the maintenance of GH hypersecretion.

Study Type: Observational

Study Design: Screening

PROTOCOL OUTLINE: Growth hormone-releasing hormone antagonist (GHRH-A) is administered to volunteers and followed with 1 of these challenges: insulin, clonidine, pyridostigmine, arginine, levodopa, growth hormone-releasing peptide, or exercise. Tests are repeated with normal saline as the control; the order of administration (control vs. pharmacologic stimulation) is randomly assigned.

Patients receive GHRH-A (dose determined in volunteer study), thyrotropin-releasing hormone, and growth-releasing hormone.

All stimulation tests follow an overnight fast.

PROTOCOL ENTRY CRITERIA:

• -Disease Characteristics-- Active acromegaly with growth hormone (GH) hypersecretion confirmed within 1 month prior to entry, i.e.: Somatomedin C elevated GH not below 2 ng/mL on standard 100 g oral glucose tolerance test Postmenopausal and hypogonadal women eligible
• Volunteers aged 18 to 30 recruited for up to 3 stimulation tests Weight within 15% of ideal
• Physical exam normal No history of disease No requirement for medication No medical or mental contraindication to protocol participation, including heavy alcohol or tobacco use
• No pregnant women --Prior/Concurrent Therapy-- Not specified --Patient Characteristics--
• Age: 18 to 65 Hematopoietic: No anemia Hepatic: No hepatic disease Renal: No renal disease
• Cardiovascular: No uncontrolled hypertension No heart disease Other: No requirement for replacement gonadal steroids, glucocorticoids, or thyroxine No mental illness No heavy alcohol use No tobacco use No drug abuse No medical contraindication to protocol therapy

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: 65 Years

Are Healthy Volunteers Accepted for this Clinical Trial?: Accepts Healthy Volunteers

Lead Sponsor: National Center for Research Resources (NCRR)

Overall Clinical Trial Officials and Contacts

Ariel Barban Study Chair University of Michigan  

Information obtained from ClinicalTrials.gov on October 06, 2008

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00004332

Study ID Number: 199/11890

ClinicalTrials.gov Identifier: NCT00004332

Health Authority: United States: Federal Government