Corticotropin Releasing Hormone (CRH) is a hypothalamic hormone made up of 41 amino acids.
Amino acids are proteins that when combined make up different substances, like hormones.
The order of amino acids in CRH, has been determined, meaning that the hormone can now be
synthetically reproduced in a laboratory setting.
When CRH is released from the hypothalamus it stimulates the pituitary gland to secrete
another hormone, ACTH. ACTH then causes the adrenal glands to make a third hormone,
cortisol. This process is known as the hypothalamic-pituitary-adrenal axis. Problems can
occur in any of the steps of this process and result in a variety of diseases (Cushing's
Syndrome and adrenal insufficiency).
Researchers hope that CRH created in a laboratory setting, ovine CRH (oCRH) can be used to
help diagnose and treat conditions of the HPA axis. This study will test the relationship
for single doses of oCRH in normal volunteers and patients with disorders of the HPA axis.
The oCRH will be injected into the patients vein as a single injection or slowly through an
IV line over 24 hours. The participants will have blood tests taken to measure hormone
levels before, during, and after receiving the oCRH.
Corticotropin-releasing hormone (CRH) is a 41 amino acid hypothalamic peptide whose chemical
structure has recently been determined after more than two decades of intensive research.
This peptide stimulates secretion of ACTH by the corticotroph cells of the pituitary gland.
As with the previously discovered hypothalamic hormones, CRH has important diagnostic and
therapeutic applications. This study seeks to explore these clinical applications by
determining the dose-response relationship for single doses of ovine CRH (oCRH) in normal
volunteers and in patients with disorders of the hypothalamic-pituitary-adrenal axis. CRH
is administered intravenously at doses up to 10 pg/kg, given as a bolus or up to 1 ug/kg/b
as a continuous infusion lasting up to 24 hours. Plasma levels of ACTH, cortisol and CRH
are measured before, during and after CRH administration.
The normal volunteers are obtained through the NIH volunteer program or are NIH employees.
Normal volunteers are in excellent health and are receiving no chronic medications.
We now routinely test patients with hypocortisolism or hypercortisolism in our clinic and