Effect of synthetic ovine corticotropin-releasing factor. Dose response of plasma adrenocorticotropin and cortisol.

Abstract

A B S T R A C T Synthetic ovine corticotropin-releasing factor (CRF) was administered to normal male volunteer subjects as an intravenous bolus or 30-s infusion. Doses of CRF ranging from 0.001 to 30 sg/kg body wt were administered, and plasma immunoreactive (IR)-ACTH and IR-cortisol concentrations were measured. The threshold dose appeared to be 0.01-0.03 ag/kg, the half-maximal dose 0.3-1 sg/kg, and the maximally effective dose 3-10 ug/kg. Basal concentrations of IR-ACTH and IR-cortisol were 14±7.6 pg/ ml (mean±SD) and 5.6±2.2 gg/dl, respectively. IR-ACTH rose as early as 2 min after CRF injection, reached peak levels in 10-15 min, and declined slowly thereafter. IR-cortisol rose at 10 min or later and reached peak levels in 30-60 min. At a dose of 30 jig/ kg, neither IR-ACTH nor IR-cortisol fell from peak levels of 82±21 pg/ml (mean±SE) and 23±1.4 ,g/dl, respectively, during the 2-h course of the experiment, indicating that CRF has a sustained effect on ACTH release and/or a prolonged circulating plasma halflife. There was little or no increase in the levels of other anterior pituitary hormones. At doses of 1 gg/ Preliminary results of these studies were presented by Dr.

Corticotropin-Releasing Factor Testing Reveals a Dose-Dependent Difference in Methadone Maintained Vs Control Subjects

“…In humans, ovine CRF (oCRF), which is the commercially available CRF used in clinical diagnostics, has a longer plasma half-life (73 min) than human CRF (hCRF) (27 min) (eg Saphier et al, 1992). Dose-response studies of oCRF, which differs by 7 amino acids from hCRF, using doses of 0.001-30 mg/kg (Orth et al, 1983) and hCRF using doses of 0.01-5 mg/kg (Schurmeyer et al, 1984) have demonstrated an apparent maximal response in cortisol at doses above 3.0 and 1.0 mg/kg, respectively. However, neither of these studies, nor any other published dose-response studies of oCRF or hCRF, achieved a maximal response (ie no plateau reached) in ACTH to the highest administered doses of CRF.…”

Arginine vasopressin potentiates adrenocorticotropin release induced by ovine corticotropin-releasing factor.

“…In man, ovine CRF (oCRF) is a potent stimulus to ACTH secretion (5) and has a prolonged duration of action (6) that is probably due to its prolonged circulating half-life in plasma (7).…”

Inconsistent stimulation of plasma ACTH through corticotropin-releasing factor in a patient with central Cushing's disease due to pituitary adenoma

“…The negative CRF test before adenomectomy remains unexplained, as there is usually a significant increase of ACTH and cortisol within the first hour of the test in patients with central CS [2,6,7,9]. Improper application of CRF is an unlikely explanation, since the patient showed the usual symptoms of flush and heat waves during both tests [7,9].…”

“…Improper application of CRF is an unlikely explanation, since the patient showed the usual symptoms of flush and heat waves during both tests [7,9].…”