Human corticotropin-releasing factor plus lysine vasopressin test during glucocorticoid therapy.

Abstract

Methods1.0 Ag/kg body wt human corticotropin-releasing factor (hCRF) and 0.005 IU/kg body wt lysine vasopressin (LVP) were administered in a bolus dose to patients receiving daily or alternate-day glucocorticoid therapy. In normal subjects with this hCRF-LVP test, the plasma ACTH increment was significantly greater (-2.5-fold) 15 min after injection than under the CRF test. In patients receiving daily glucocorticoid therapy (> 15 mg prednisolone or an equivalent daily dose), the plasma ACTH and cortisol responses to hCRF-LVP were suppressed 2 wk to 1 mo after the beginning of glucocorticoid administration but partially improved at 2-10 mo, and was markedly suppressed several years later. On the other hand, in patients receiving alternate-day glucocorticoid therapy, the plasma ACJ7H response was normal at 2 wk, normal or higher at 1-3 mo, and normal after 4 mo. A normal plasma cortisol response was observed throughout the test period in patients receiving alternate-day therapy after pulse therapy, whereas plasma cortisol response was gradually improved in patients receiving alternate-day therapy after several months of daily therapy.

A Synergistic Adrenocorticotropin Response to Naloxone and Vasopressin in Normal Humans: Evidence That Naloxone Stimulates Endogenous Corticotropin-Releasing Hormone

“…Dose-response studies of intravenous AVP administration to normal humans have demonstrated that while a peripheral plasma AVP concentration of 60 pmol/1 does not stimulate ACTH and cortisol release [42], levels of 135 pmol/1 cause a significant rise in both ACTH and cortisol [43]. Considerably lower AVP concentrations of 5-10 pmol/1, achieved by hypertonic saline infusion, will augment the stimulatory effect of synthetic CRH in vivo [6,7], and this is consistent with reports that very low intra venous doses of AVP or LVP, which do not by themselves significantly increase ACTH levels above basal, still sub stantially increase the ACTH response to human or ovine 203 CRH [41,[44][45][46]. In the present study, plasma AVP levels were greater than 220 prnol/1 (considerably greater than the above threshold for ACTH release) 15 min prior to the peak ACTH responses (i.e., 10 min after AVP was admin istered) in all three tests in which active AVP was given.…”

Potentiation of the classic ovine corticotrophin releasing hormone stimulation test by the combined administration of small doses of lysine vasopressin

“…Three previous studies used smaller doses of LVP (either 0.35 or 0.5 IU, but in the form of i.v. bolus injections) combined with 50-100 pg hCRH(Spath-Schwalbe, 1987;Hashimoto et al, 1988; Arai & Takabe, 1991).…”