ABSTRACT
BACKGROUND: Topical corticosteroids (TCS) are typically used for extended periods of time for chronic skin conditions, including psoriasis. Chronic TCS use may result in side effects similar to those of systemic corticosteroids. Patients may have subclinical adrenal suppression and be unaware of their risk in the case of serious trauma.
OBJECTIVE: The objective of this study was to investigate the real world effects of chronic TCS use and its effects on adrenal suppression in a chronic disease such as psoriasis.
MATERIALS: This retrospective study utilized data from screening visits of a psoriasis clinical trial in which subjects had been on chronic TCS.
RESULTS: In this study, subjects with moderate to severe psoriasis affecting 16-20% of total body surface area (BSA) and using high-potency TCS at screening had a lower post-cosyntropin cortisol level (18.83 mcg/dL) compared to those with moderate psoriasis involving 10-15% of total BSA and using lower potency TCS at screening (23.22 mcg/dL; P=0.03). Both subject groups had lower post-cosyntropin cortisol levels compared to normal, healthy adults (P<0.001 for both).
CONCLUSION: This suggests that real world chronic use of high potency TCS over a larger BSA may result in silent adrenal suppression.
J Drugs Dermatol. 2016;15(8):945-948.
Subject(s)
Adrenal Cortex Hormones/blood , Glucocorticoids/administration & dosage , Psoriasis/blood , Psoriasis/drug therapy , Administration, Cutaneous , Adrenal Cortex Hormones/antagonists & inhibitors , Adult , Aged , Body Surface Area , Cosyntropin/antagonists & inhibitors , Cosyntropin/blood , Drug Administration Schedule , Female , Glucocorticoids/adverse effects , Humans , Hydrocortisone/antagonists & inhibitors , Hydrocortisone/blood , Male , Middle Aged , Psoriasis/diagnosis , Retrospective StudiesABSTRACT
In rats subjected to myocardial ischemia/reperfusion, melanocortin peptides, including gamma(1)-melanocyte-stimulating hormone (gamma(1)-MSH), are able to exert a protective effect by stimulating brain melanocortin MC(3) receptors. A non-melanocortin receptor belonging to a group of receptors for Phe-Met-Arg-Phe-NH(2) (FMRFamide)-like peptides may be involved in some of the cardiovascular effects of the gamma-MSHs. FMRFamide-like peptides and gamma(1)-/gamma(2)-MSH share, among other things, the C-terminal Arg-Phe sequence, which seems to be essential for cardiovascular effects in normal animals. So we aimed to further investigate which receptor and which structure are involved in the protective effects of melanocortins in anesthetized rats subjected to myocardial ischemia by ligature of the left anterior descending coronary artery (5 min), followed by reperfusion. In saline-treated rats, reperfusion induced, within a few seconds, a high incidence of ventricular tachycardia and ventricular fibrillation, and a high percentage of death within the 5 min of observation period. Reperfusion was associated with a massive increase in free radical blood levels and with an abrupt and marked fall in systemic arterial pressure. The i.v. treatment (162 nmol/kg) during the ischemic period with the adrenocorticotropin fragment 1-24 [ACTH-(1-24): the reference protective melanocortin which binds all melanocortin receptors], as well as with both the melanocortin MC(3) receptor agonists gamma(2)-MSH and [D-Trp(8)]gamma(2)-MSH, reduced the incidence of ventricular tachycardia, ventricular fibrillation and death, the increase in free radical blood levels and the fall in arterial pressure. On the contrary, gamma(2)-MSH-(6-12) (a fragment unable to bind melanocortin receptors) was ineffective. Such protective effect was prevented by the melanocortin MC(3)/MC(4) receptor antagonist SHU 9119. In normal (i.e., not subjected to myocardial ischemia/reperfusion) rats, the same i.v. dose (162 nmol/kg) of gamma(2)-MSH, [D-Trp(8)]gamma(2)-MSH and gamma(2)-MSH-(6-12) provoked a prompt and transient increase in arterial pressure; on the other hand, ACTH-(1-24), which lacks the C-terminal Arg-Phe sequence, decreased arterial pressure, but only at higher doses. Heart rate of normal rats was not affected by any of the assayed peptides. The present data confirm and extend our previous findings that melanocortins prevent myocardial reperfusion injury by activating melanocortin MC(3) receptors. Moreover, they further support the notion that, in normal rats, cardiovascular effects of gamma-MSHs are mediated by receptors for FMRFamide-like peptides, for whose activation, but not for that of melanocortin MC(3) receptors, the C-terminal Arg-Phe structure being relevant.
Subject(s)
Cosyntropin/pharmacology , Melanocyte-Stimulating Hormones/pharmacology , Myocardial Reperfusion Injury/prevention & control , Receptor, Melanocortin, Type 3/drug effects , alpha-MSH/pharmacology , gamma-MSH/pharmacology , Animals , Coronary Disease/complications , Coronary Disease/physiopathology , Cosyntropin/antagonists & inhibitors , Cosyntropin/blood , FMRFamide/chemistry , FMRFamide/metabolism , Female , Hypotension/complications , Hypotension/drug therapy , Hypotension/prevention & control , Injections, Intravenous , Lidocaine/pharmacology , Male , Melanocyte-Stimulating Hormones/physiology , Myocardial Reperfusion Injury/complications , Myocardial Reperfusion Injury/mortality , Rats , Rats, Wistar , Receptor, Melanocortin, Type 3/physiology , Signal Transduction , Tachycardia, Ventricular/complications , Tachycardia, Ventricular/prevention & control , Time Factors , Ventricular Fibrillation/complications , Ventricular Fibrillation/prevention & control , alpha-MSH/physiology , gamma-MSH/antagonists & inhibitors , gamma-MSH/chemistry , gamma-MSH/physiologyABSTRACT
Cytokines are autocrine, paracrine and endocrine glycoproteins that interact with specific cell receptors and have pleiotropic effects. Increasing evidence indicates that cytokines, immune interferon (IFN-gamma) and interleukin 6 (IL-6) among others, modulate hypothalamic-pituitary-adrenal function. Corticostatins/defensins are a family of cationic peptides recently isolated from phagocytic cells of myeloid lineage. Four peptides have been isolated from human neutrophils: HP-1, 2, 3 and 4. As defensins they participate in immunosurveillance against viruses, bacteria and fungi. Some members of the family are also able to inhibit ACTH-induced steroidogenesis. Among human peptides, only HP-4 is corticostatic. We previously demonstrated that HP-1 and HP-4 inhibit in vitro the spontaneous and cytokine-inducible natural killer activity of human peripheral blood mononuclear cells (PBMC) and potentiate cortisol-dependent inhibition. The present work was carried out to determine whether two human corticostatins/defensins, HP-1 and HP-4, were able to modulate in vitro IFN-gamma and IL-6 production by human PBMC stimulated with phytohemagglutinin or Concanavalin A. IFN-gamma was titrated using biological assay with WISH cells as indicators and vesicular stomatitis virus as the challenge virus. IL-6 was measured by means of enzyme amplified sensitivity immunoassay. Both HP-1 and HP-4 significantly reduced cytokine production. Our data indicate that HP-1 and HP-4 are novel modulators of lymphocyte functions in vitro. Their depressing properties on ACTH-induced steroidogenesis and on cytokine production add complexity to neuroendocrine-immune circuits involving hypothalamic-pituitary-adrenal function.
Subject(s)
Anti-Infective Agents/pharmacology , Antifungal Agents/pharmacology , Blood Bactericidal Activity , Blood Proteins/pharmacology , Cosyntropin/antagonists & inhibitors , Cytokines/biosynthesis , Neutrophils/immunology , Peptides/pharmacology , alpha-Defensins , Anti-Bacterial Agents , Concanavalin A/pharmacology , Cytokines/analysis , Defensins , Female , Humans , Immunoenzyme Techniques , In Vitro Techniques , Intercellular Signaling Peptides and Proteins , Interferon-gamma/analysis , Interferon-gamma/biosynthesis , Interleukin-6/analysis , Interleukin-6/biosynthesis , Killer Cells, Natural/drug effects , Killer Cells, Natural/metabolism , Male , Mitogens/pharmacology , Phytohemagglutinins/pharmacologyABSTRACT
The possible involvement of the ACTH-(11-24) fragment on the stretchings, yawnings and penile erections induced by the intracerebroventricular injection of ACTH-(1-24) in rats, was studied. The results indicate that this C-terminal fragment is devoid of any behavioral activity, but inhibits the behavioral syndrome induced by ACTH-(1-24). This suggests that the fragment-(11-24) of the ACTH molecule may contain or represent an address sequence for brain ACTH receptors and may be involved in the termination of the behavioral response to melanocortins.
Subject(s)
Behavior, Animal/drug effects , Cosyntropin/antagonists & inhibitors , Cosyntropin/pharmacology , Peptide Fragments/pharmacology , Animals , Male , Penile Erection/drug effects , Rats , Rats, WistarABSTRACT
Corticostatins (CS)-defensins are a family of peptides recently isolated from neutrophils and cells of myeloid lineage. They have been termed CS in that members of the family inhibit ACTH-induced steroidogenesis, and defensins in that they are highly effective as enhancers of intracellular killing of pathogens. Natural killer (NK) cells are an immunocyte subset whose cytotoxic activity is modulated by lymphokines and hormones. Recent evidence suggests a myeloid origin for these cells. We evaluated whether two human CS-defensins, HP-1 and HP-4, are able to modulate in vitro spontaneous NK cell activity of human peripheral blood mononuclear (PBM) cells and in vitro susceptibility to the stimulatory effect by immune interferon (IFN-gamma) or interleukin 2 (IL-2) and to the inhibitory effect of cortisol. PBM cells were incubated for 20 h with HP-1 or HP-4 and IFN-gamma or IL-2 or cortisol. NK cell activity was measured in a 4-h direct cytotoxicity assay (K562 cells as a target). We also searched for CS-defensins in NK-enriched cell preparations by means of HPLC separation of the supernatant obtained from sonicated cells. HP-1 and HP-4 significantly inhibited both spontaneous and lymphokine-inducible NK cell activity, and potentiated cortisol-dependent inhibition. Radioimmunoassay on HPLC purified fractions demonstrated the presence of HP-1 in NK-enriched cell preparations. Our data indicate that HP-1 and HP-4 are negative modulators of NK cell cytotoxicity and that autocrine/paracrine mechanisms are conceivably involved. HP-1 production by NK cells may be viewed as additional support for the thesis of the myeloid origin of these immune effectors.
Subject(s)
Blood Proteins/pharmacology , Cosyntropin/antagonists & inhibitors , Killer Cells, Natural/drug effects , Neutrophils/immunology , Peptides/pharmacology , alpha-Defensins , Cell Separation , Cytotoxicity Tests, Immunologic/methods , Cytotoxicity, Immunologic/drug effects , Cytotoxicity, Immunologic/immunology , Defensins , Humans , Hydrocortisone/pharmacology , Intercellular Signaling Peptides and Proteins , Killer Cells, Natural/immunology , Lymphokines/pharmacologyABSTRACT
A volume-controlled hemorrhagic shock was produced in anesthetized rats by intermittent bleeding from an iliac vein over a period of 20-30 min, until the carotid mean arterial pressure (MAP) stabilized around 20-24 mmHg. In this condition, which caused the death of all saline-treated animals within 25-30 min, the intravenous (i.v.) bolus injection of the adrenocorticotropin fragment 1-24 (ACTH(1-24)) at a dose of 160 micrograms/kg promptly restored MAP, as well as pulse pressure, heart rate and respiratory function, and greatly prolonged the survival time. Capsaicin (125 mg/kg cumulatively, s.c., 1 week before) completely prevented the anti-shock effect of ACTH(1-24), which, on the other hand, was shared by i.v. [Nle11]-substance P (SP) (200-300 micrograms/kg). Finally the SP-antagonist [D-Arg1,D-Pro2,D-Trp7,9,Leu11]-SP prevented the effect of ACTH(1-24). These results suggest that SP-containing nerve fibers are required for the effect of ACTH in hemorrhagic shock.
Subject(s)
Adrenocorticotropic Hormone/antagonists & inhibitors , Capsaicin/pharmacology , Cosyntropin/antagonists & inhibitors , Hemodynamics/drug effects , Neurons, Afferent/physiology , Recombinant Proteins , Shock, Hemorrhagic/physiopathology , Substance P/analogs & derivatives , Substance P/physiology , Adrenocorticotropic Hormone/therapeutic use , Afferent Pathways/drug effects , Animals , Capsaicin/toxicity , Cosyntropin/therapeutic use , Endorphins/physiology , Female , Male , Neurons, Afferent/drug effects , Rats , Rats, Wistar , Shock, Hemorrhagic/drug therapy , Substance P/antagonists & inhibitors , Substance P/pharmacology , Substance P/therapeutic use , Survival RateABSTRACT
Using an antiserum against synthetic rabbit corticostatin-1 (CS-1), we established a specific RIA for CS-1 and examined its distribution in various tissues, including the hypothalamic-pituitary-adrenal axis. Among the tissues examined, the highest levels of CS-1-like immunoreactivity (-LI) were found in the lung and spleen. CS-1-LI was also detected at relatively high levels in the pituitary, adrenal medulla, and small intestine, while it was barely detectable in the hypothalamus. Immunocytochemical studies revealed the widespread distribution of CS-1 in these tissues. Plasma CS-1 levels averaged 7.8 ng/ml and increased to 185.4 ng/ml in the presence of infection. CS-1-LI in the adrenal gland, small intestine, and hypothalamus also increased in rabbits with active inflammation. These data suggest that CS-1 may modify the hypothalamic-pituitary-adrenal axis in an endocrine or paracrine manner in response to infection.
Subject(s)
Hypothalamo-Hypophyseal System/chemistry , Peptides/analysis , Peptides/immunology , Pituitary-Adrenal System/chemistry , Animals , Chromatography, Gel , Chromatography, High Pressure Liquid , Cosyntropin/antagonists & inhibitors , Immunohistochemistry , Intercellular Signaling Peptides and Proteins , Intestine, Small/chemistry , Peptides/blood , Rabbits , RadioimmunoassayABSTRACT
ACTH-(1-24) dose-dependently improved cardiovascular function in rats and dogs subjected to experimental hemorrhagic shock, and intravenous dose of 160 and 100/microgram/kg, respectively, completely restoring arterial blood pressure and pulse amplitude. All saline-treated animals died within 30 min of bleeding, while all ACTH-treated animals were still alive at the end of the observation period (2 hr). The injection of ACTH-(1-24) also dramatically improved the respiratory function. Morphine, i.v. injected into rats at the dose of 2.5 mg/kg, antagonised the effect of ACTH-(1-24) to a greater or lesser degree, depending on the dose of peptide employed: at 160/microgram/kg, antagonism was complete, at 320/microgram/kg antagonism was only partial, while at 480/microgram/kg antagonism was almost completely overcome. These data further support the idea that melanocortins are physiological antagonists of opioids, and suggest that melanocortin peptides may prove to be rational and effective drugs in the treatment of hypovolemic shock.
Subject(s)
Adrenocorticotropic Hormone/antagonists & inhibitors , Cosyntropin/antagonists & inhibitors , Morphine/pharmacology , Shock, Hemorrhagic/drug therapy , Animals , Blood Pressure/drug effects , Cosyntropin/therapeutic use , Dogs , Female , Heart Rate/drug effects , Naloxone/pharmacology , Rats , Rats, Inbred Strains , Respiration/drug effects , Shock, Hemorrhagic/physiopathologyABSTRACT
ACTH-(1-24), intravenously injected at the dose of 160 micrograms/kg to rats bled to the point of otherwise irreversible hypovolemic shock, causes a prompt and sustained increase in blood pressure and pulse amplitude, all treated rats surviving at the end of the experiment (2 hr). Bilateral vagotomy, as well as atropine sulphate (2 mg/kg i.p. immediately before bleeding), almost completely abolishes the anti-shock activity of ACTH. These data indicate that a central cholinergic pathway and vagal afferent (but not efferent) fibers play an important role in the anti-shock effect of ACTH.
Subject(s)
Adrenocorticotropic Hormone/therapeutic use , Atropine/pharmacology , Cosyntropin/therapeutic use , Shock/prevention & control , Vagotomy , Animals , Blood Pressure/drug effects , Cosyntropin/antagonists & inhibitors , Cosyntropin/pharmacology , Female , Pulse/drug effects , Rats , Rats, Inbred Strains , Shock/physiopathologyABSTRACT
Experiments were conducted to compare the blood pressure and heart rate responses of conscious rats given intracerebroventricular (ICV) injections of adrenocorticotropin (ACTH 1-24) and corticotropin releasing factor (CRF). Under sodium pentobarbital anaesthesia, rats were implanted with a stainless-steel cannula into the lateral cerebral ventricle and had their right femoral artery and vein cannulated. Upon recovery (24-48 hr later) conscious, unrestrained rats were given ICV injections (total volume 5 microliter by gravity flow) of sterile saline, ACTH (1-24) (0.85 and 1.7 nmoles) or CRF (0.55 and 1.1 nmoles) and blood pressure and heart rate were monitored over the next 2 hr (from the abdominal aorta via the femoral arterial catheter). Both ACTH and CRF caused mean arterial pressure (MAP) to increase, which was paralleled with increases in mean heart rate (MHR). Moreover, these elevations in MAP and MHR were temporally associated with excessive grooming (for ACTH) and locomotor activity (for CRF), which occurred before and lasted as long as MAP and MHR were enhanced. Intravenous (IV) pretreatment whereby naloxone was given 10 min before ICV administration of ACTH (1.7 nmoles) or CRF (1.1 nmoles), showed that naloxone blocked the behavioral, pressor and tachycardic effects of both ACTH and CRF. The results demonstrate that the pressor, tachycardic and locomotor effects evoked in conscious rats by ICV administration of ACTH or CRF are antagonized by naloxone and that their hemodynamic changes may, in part, be mediated by prior behavioral activation.
Subject(s)
Adrenocorticotropic Hormone/pharmacology , Blood Pressure/drug effects , Cerebral Ventricles/physiology , Corticotropin-Releasing Hormone/pharmacology , Cosyntropin/pharmacology , Grooming/drug effects , Heart Rate/drug effects , Motor Activity/drug effects , Naloxone/pharmacology , Animals , Cerebral Ventricles/drug effects , Corticotropin-Releasing Hormone/administration & dosage , Corticotropin-Releasing Hormone/antagonists & inhibitors , Cosyntropin/administration & dosage , Cosyntropin/antagonists & inhibitors , Injections, Intraventricular , Male , Rats , Rats, Inbred StrainsABSTRACT
Controversy surrounds the issue of whether beta-endorphin affects adrenal steroidogenesis. Recent work has both supported and refuted the claim that beta-endorphin stimulates a rise in serum aldosterone. We investigated the role of beta-endorphin in adrenal steroidogenesis by examining its potential modulation of the response of serum cortisol to exogenous ACTH (Cosyntropin). Four of five normal men received: 1) synthetic beta-endorphin (1 microgram/kg X min) for 30 min, followed by a bolus dose of 0.2 micrograms ACTH; 2) beta-endorphin (100 micrograms, iv), followed by 0.2 micrograms ACTH iv; 3) 0.2 micrograms ACTH iv; and 4) beta-endorphin (100 micrograms iv) alone. The integrated cortisol response to exogenous ACTH, calculated as the area under the cortisol response curve, was significantly less when the ACTH infusion was preceded by the 30-min beta-endorphin infusion than when administered alone [163 +/- 50 (SE) microgram/dl X min vs. 282 +/- 51 micrograms/dl X min, respectively; P less than 0.01]. By contrast, there was no difference between the integrated cortisol response to exogenous ACTH alone and exogenous ACTH after the bolus dose of beta-endorphin (282 +/- 51 vs. 293 +/- 39 micrograms/dl X min, respectively). Beta-Endorphin (30-min infusion or 100-micrograms bolus dose alone) caused no change in serum aldosterone, dehydroepiandrosterone, or PRA. Serum PRL levels, however, were raised significantly (P less than 0.05) by the 30-min infusion of beta-endorphin. The infusion and bolus doses of beta-endorphin raised plasma beta-endorphin levels to over 100,000 pg/ml and 5,000 pg/ml, respectively. We conclude that very high plasma levels of beta-endorphin may influence the response of cortisol to ACTH through a direct effect on the adrenal cortex. However, even in disease states such as Addison's and Nelson's diseases, such levels of plasma beta-endorphin are not known to be achieved.
Subject(s)
Adrenocorticotropic Hormone/analogs & derivatives , Cosyntropin/pharmacology , Endorphins/pharmacology , Hydrocortisone/blood , Adult , Aldosterone/blood , Cosyntropin/antagonists & inhibitors , Dehydroepiandrosterone/blood , Dose-Response Relationship, Drug , Endorphins/blood , Humans , Male , Prolactin/blood , Renin/blood , Time Factors , beta-EndorphinABSTRACT
Bombesin, beta-endorphin and ACTH-(1-24) induce excessive grooming behavior in rats. Whereas ACTH increases the frequency of all components of grooming behavior (head washing, bodily grooming and paw licking), the most pronounced element of bombesin- and beta-endorphin-induced excessive grooming is scratching. Naloxone counteracts peptide-induced grooming and in particular excessive scratching is reduced by this opiate antagonist. Also neurotensin suppresses peptide-induced grooming behavior and in particular scratching. It is concluded that the element scratching is the component of grooming behavior which is mainly displayed by activation of opiate receptors and that neurotensin is able to interfere with opiate receptor mediated behavior.
Subject(s)
Bombesin/pharmacology , Cosyntropin/pharmacology , Grooming/drug effects , Naloxone/pharmacology , Neurotensin/pharmacology , beta-Endorphin/pharmacology , Animals , Bombesin/antagonists & inhibitors , Cosyntropin/antagonists & inhibitors , Male , Rats , Rats, Inbred Strains , beta-Endorphin/antagonists & inhibitorsABSTRACT
The unilateral microinjection of ACTH 1-24 (20 nmol) into the locus coeruleus (LC) produced a long lasting (2-3 hr) posture asymmetry and movement disorder in all rats tested. This response was readily suppressed by the subsequent local microinjection of an equimolar dose of beta-endorphin or morphine or by the intraperitoneal injection of morphine sulphate (50 mg/kg). Microinjection of naloxone (20 nmol) into the LC produced the above syndrome in a lower percentage of animals. The results support the hypothesis that ACTH peptides and opioids play opposite roles in the control of different brain functions.
Subject(s)
Adrenocorticotropic Hormone/analogs & derivatives , Cosyntropin/antagonists & inhibitors , Dyskinesia, Drug-Induced , Endorphins/pharmacology , Locus Coeruleus/drug effects , Morphine/pharmacology , Posture , Animals , Cosyntropin/administration & dosage , Cosyntropin/pharmacology , Endorphins/administration & dosage , Male , Microinjections , Morphine/administration & dosage , Naloxone/administration & dosage , Naloxone/pharmacology , Rats , Rats, Inbred Strains , beta-EndorphinABSTRACT
Dispersed guinea-pig adrenal cells can be maximally stimulated to secrete cortisol by adrenocorticotrophin (ACTH greater than 50 ng/l). Further, this stimulation appears to be specific to ACTH alone, with other naturally occurring chemicals (e.g. steroids, protein hormones) at supra-physiological concentrations being without effect on cortisol production. The effect of drugs of differing structure and therapeutic function (aminogluthethimide, metyrapone, trilostane, 17-ketotrilostane, danazol, epostane, megestrol acetate, stanozolol and etomidate) on ACTH-stimulated (50 ng/l) cortisol production has been tested in this system. All the drugs depressed steroid output in a similar dose-related fashion. The concentration of drug which inhibited cortisol output by 50% was (mumol/l, mean +/- SEM): etomidate 0.097 +/- 0.002: epostane 0.44 +/- 0.02: 17-ketotrilostane 0.55 +/- 0.04: trilostane 1.3 +/- 0.1: metyrapone 3.5 +/- 0.6: megestrol acetate, 11 +/- 2: danazol 22 +/- 2: aminogluthethimide 41 +/- 5: stanozolol 50 +/- 4. Thus, etomidate, an anaesthetic, is more potent than the established anti-steroidogenic drugs metyrapone, aminogluthethimide and trilostane. Further, direct anti-steroidogenic effects have been demonstrated for megestrol acetate and stanozolol for the first time. We conclude that this technique offers a promising new approach to the assessment of biological potency of drugs affecting endocrine tissues.
Subject(s)
Adrenal Glands/metabolism , Steroids/biosynthesis , Adrenal Glands/drug effects , Animals , Cosyntropin/antagonists & inhibitors , Cosyntropin/pharmacology , Guinea Pigs , Kinetics , MaleABSTRACT
Intravenous injection of (1-24) ACTH and 2-deoxy-d-glucose (2DG) stimulated the plasma epinephrine and norepinephrine levels in pentobarbital-anesthetized male rats. Naloxone, a specific opiate antagonist, inhibited the plasma epinephrine response to ACTH but not to 2DG. Norepinephrine release induced by ACTH or 2DG was not affected by naloxone. These results suggest that the opioid peptidergic synapse might be involved in the ACTH- but not in the 2DG-induced epinephrine release.