Effects of corticotropin-releasing hormone on proopiomelanocortin derivatives and monocytic HLA-DR expression in patients with septic shock.

Little is known about interactions between immune and neuro-endocrine systems in patients with septic shock. We therefore evaluated whether the corticotropin-releasing hormone (CRH) and/or proopiomelanocortin (POMC) derivatives [ACTH, ß-endorphin (ß-END), ß-lipotropin (ß-LPH), α-melanocyte stimulating hormone (α-MSH) or N-acetyl-ß-END (Nac-ß-END)] have any influences on monocyte deactivation as a major factor of immunosuppression under septic shock conditions. Sixteen patients with septic shock were enrolled in a double-blind, cross-over and placebo controlled clinical study; 0.5µg/(kgbodyweighth) CRH (or placebo) were intravenously administered for 24h. Using flow cytometry we investigated the immunosuppression in patients as far as related to the loss of leukocyte surface antigen-DR expression on circulating monocytes (mHLA-DR). ACTH, ß-END immunoreacive material (IRM), ß-LPH IRM, α-MSH and Nac-ß-END IRM as well as TNF-α and mHLA-DR expression were determined before, during and after treatment with CRH (or placebo). A significant correlation between plasma concentration of α-MSH and mHLA-DR expression and an inverse correlation between mHLA-DR expression and TNF-α plasma level were found. Additionally, a significant increase of mHLA-DR expression was observed 16h after starting the CRH infusion; 8h later, the mHLA-DR expression had decreased again. Our results indicate that the up-regulation of mHLA-DR expression after CRH infusion is not dependent on the release of POMC derivatives. From the correlation between plasma concentration of α-MSH and mHLA-DR expression, we conclude that in patients with septic shock the down-regulation of mHAL-DR expression is accompanied by the loss of monocytic release of α-MSH into the cardiovascular compartment.

Hemodynamic actions of corticotropin-releasing hormone and proopiomelanocortin derivatives in septic patients.

Proopiomelanocortin (POMC) derivatives and mRNA of POMC have been detected in cardiomyocytes and vascular smooth muscle cells. Increased plasma levels of POMC derivatives have been found in septic patients during cardiovascular deregulation; therefore, we evaluated whether corticotroph-type (ACTH, ß-endorphin, ß-lipotropin) or melanotroph-type (α-melanocyte-stimulating hormone and N-acetyl-ß-END) POMC derivatives have influences on patients' hemodynamics during sepsis. Seventeen septic patients were monitored by pulmonary artery catheter and corticotropin-releasing hormone (CRH) tests were performed by intravenous administration of 100 µg CRH. Before, 15, 30, 45, and 60 minutes after CRH administration, hemodynamic variables were measured, and plasma concentrations of POMC derivatives were determined. After CRH administration, heart rate, cardiac index, and stroke index increased, and the systemic vascular resistance index decreased; moreover, a correlation between ACTH concentration and stroke index as well as an inverse correlation between (α-melanocyte-stimulating hormone concentration and systemic vascular resistance index was observed. CRH and ACTH may have opposite effects on the blood pressure (mean arterial pressure). Immediately after CRH injection mean arterial pressure decreased. ACTH (in contrast to ß-endorphin or ß-lipotropin), released into the cardiovascular compartment 15 minutes after CRH injection, might have raised mean arterial pressure as compatible with the correlation between ACTH levels and stroke index. (α-melanocyte-stimulating hormone appears to have a vasodilative effect during sepsis.

Response of proopiomelanocortin and gonado- or lactotroph systems to in-vitro fertilisation procedures stress.

OBJECTIVE: To analyse for the first time the response of the corticotroph-type and the melanotroph-type pituitary proopiomelanocortin (POMC) system with regard to in-vitro fertilisation (IVF) treatment using self-developed highly specific non-cross-reacting radioimmunoassay. SETTING: University hospital. patients: A total of 28 patients undergoing IVF oocyte retrieval. Cross sectional exploratory study, one factorial design with repeated measurements on one factor, non-parametric tests. Blood was collected before anaesthesia (t(A)) (n=28) and immediately after oocyte retrieval (t(B)) (n=28). MAIN OUTCOME MEASURE(S): beta-endorphin immunoreactive material (IRM), acetyl-N-beta-endorphin IRM, beta-lipotropin IRM, ACTH, cortisol, estradiol, progesterone, prolactin, luteinizing hormone, and follicle-stimulating hormone. For determination of authentic beta-endorphin [beta-endorphin (1-31)] a highly specific two-site fluid phase immunoprecipitation radioimmunoassay was developed, which did not cross-react with any beta-endorphin derivative or any other opioid peptide tested. RESULTS: No response of acetyl-N-beta-endorphin IRM and of authentic beta-endorphin (1-31) was observed to oocyte retrieval in contrast to a significant increase of corticotroph-type proopiomelanocortin derivatives. A significant rise in prolactin plasma concentration indicates a pronounced lactotroph response to oocyte retrieval stress. No significant correlation between POMC derivates and prolactin and between POMC derivatives and gonadotropins or sexual steroids except for ACTH and progesterone and for beta-endorphin IRM and estradiol was observed. CONCLUSION: IVF treatment stress led to significant corticotroph-type POMC and lactotroph responses, but not to responses of authentic beta-endorphin or melanotroph-type POMC in women undergoing oocyte retrieval.

Plasma levels of corticotroph-type pro-opiomelanocortin derivatives such as beta-lipotropin, beta-endorphin(1-31), or adrenocorticotropic hormone are correlated with severity of postoperative pain.

BACKGROUND: In the pituitary of lower species, pro-opiomelanocortin is expressed in corticotroph cells of the anterior and in melanotroph cells of the neurointermediate lobe; enzymatic processing in the corticotrophs results in the release of adrenocorticotropic hormone, beta-lipotropin, or beta-endorphin. In the melanotrophs, these fragments are further modified, eg, by N-terminal acetylation. In the human pituitary, these enzyme systems are located within the same cells in the anterior lobe. We studied the reactions of the pro-opiomelanocortin system under preoperative conditions as well as under postoperative pain. METHODS: In 17 patients undergoing hip or knee arthroplasty, we determined plasma concentrations of N-acetyl-beta-endorphin immunoreactive material, authentic beta-endorphin [beta-endorphin(1-31)], adrenocorticotropic hormone, beta-lipotropin immunoreactive material, and cortisol, as well as pain severity rated by the patients using a visual analogue scale before surgery, after surgery but still under spinal anesthesia, under postoperative pain, and 1 day after surgery. RESULTS: Only low levels of N-acetyl-beta-endorphin immunoreactive material were measured in 16 out of 17 patients. High concentrations (1st quartile/median/3rd quartile; pmol/L) of adrenocorticotropic hormone (22.5/55.8/124) and beta-lipotropin immunoreactive material (6.6/34.6/142) were observed under postoperative pain, accompanied by a small increase of beta-endorphin(1-31) concentrations (0.0/6.1/10.9). Preoperatively small but significantly elevated levels of corticotroph-type and melanotroph-type pro-opiomelanocortin derivatives were observed; in contrast, spinal anesthesia suppressed all pro-opiomelanocortin fragment release. Postoperative pain severity correlated with postoperative adrenocorticotropic hormone, beta-lipotropin immunoreactive material, and beta-endorphin(1-31) concentrations. CONCLUSIONS: We conclude that the melanotroph-type pro-opiomelanocortin system is not activated under postoperative pain; the increase of corticotroph-type pro-opiomelanocortin fragment levels is different in quantity and proportion under preoperative conditions or postoperative pain, respectively.

Corticotropin-releasing hormone reduces pressure pain sensitivity in humans without involvement of beta-endorphin(1-31), but does not reduce heat pain sensitivity.

In the present study the effects of intravenously administered corticotropin-releasing hormone (CRH) on the release of proopiomelanocortin (POMC) derivatives such as adrenocorticotropic hormone (ACTH), beta-lipotropin (beta-LPH) and beta-endorphin (beta-END) as well as direct effects of CRH on pain sensitivity were examined. In 16 healthy volunteers we studied the effects of 100 microg intravenously administered CRH in absence or presence of 12 mg naloxone on heat or pressure pain sensitivity, using a double-blind, cross-over and placebo-controlled design. To evaluate analgesic effects of CRH via release of POMC derivatives, we determined plasma concentrations of beta-END-immunoreactive material (IRM), authentic beta-END (beta-END(1-31)) and beta-LPH IRM, in parallel with heat and pressure pain tolerance thresholds before and 15 and 30 min after treatment with CRH (or placebo), and 5 min after naloxone (or placebo) administration which was administered 40 min after CRH (or placebo) injection. CRH increased levels of beta-END IRM, beta-END(1-31) and beta-LPH IRM. As compared to beta-END IRM levels measured by a commercial RIA kit, the beta-END(1-31) levels determined by a highly specific two-site RIA, proved to be remarkably small. Furthermore, CRH did not induce increases of heat pain tolerance thresholds, but of pressure pain tolerance thresholds, which, however, were not reversible by naloxone. Neither beta-END nor beta-LPH IRM nor beta-END(1-31) levels correlated with heat or pressure pain tolerance thresholds. We conclude that CRH does not modulate heat, but pressure pain; POMC derivatives like beta-END IRM, beta-END(1-31) or beta-LPH do not mediate this effect.

Elevated plasma beta-endorphin/beta-lipotropin concentration following a radius fracture.

Plasma beta-endorphin/beta-lipotropin concentration was assessed soon after a fracture. Blood samples from 14 patients with radius fractures were obtained from both arms soon after admission to the hospital (mean 245 min) after the accident. Follow-up samples were taken after healing of the fractures. Higher plasma beta-endorphin/beta-lipotropin concentrations were found in blood samples taken soon after a fracture in both arms compared with the concentrations after healing of the fracture. At admission, mean beta-endorphin/beta-lipotropin concentrations in the fractured and the contralateral arms were 12.7 pmol/L and 13.2 pmol/L, and after recovery 11.1 pmol/L and 11.5 pmol/L (p = 0.012 and p = 0.041), respectively. The pain decreased according to the visual analogue scale (VAS) (0-10) from 4.64 at admission to 0.58 after healing (p < 0.001). In conclusion, this study showed that beta-endorphin/beta-lipotropin concentrations are increased in both arms following a radius fracture compared to the level after the fracture has healed.

Elevated plasma level of lipotropin revealing an occult carcinoid tumor with normal plasma adrenocorticotropin.

The increases in the level of plasma lipotropin (LPH) and in the LPH/ACTH ratio are considered diagnostic tools in ectopic ACTH syndrome. However, plasma ACTH is also elevated in this syndrome. We report a case of a small carcinoid tumor with an increase in both ACTH and LPH in plasma before surgery. Eight months after the tumoral resection, plasma LPH alone was increased again, whereas plasma ACTH and plasma and urinary cortisol remained normal in this apparently cured patient. This repeated abnormality was the only available feature that allowed successful removal of the occult tumoral residue.

White Addison's disease: what is the possible cause?

A case of chronic primary adrenal insufficiency without hyperpigmentation in a 64-year-old woman is reported. Due to the absence of hyperpigmentation the diagnosis was delayed and she became critically ill. During endocrine evaluation, in order to investigate the mechanism responsible for the absence of hyperpigmentation, skin biopsy was done and hormones responsible for the skin pigmentation were measured. Absence of hyperpigmentation is explained by high degree of melanosome degradation in secondary lysosomes called "compound melanosomes", which overwhelmed increased stimulation of the skin pigmentation. Melanocyte-stimulating hormones were elevated with a strikingly high beta-LPH/ACTH ratio. To our knowledge, this is the first study of pathogenic mechanisms responsible for the absence of hyperpigmentation in white Addison's disease.

Peripheral plasma levels of beta-endorphin in alcoholics and highly trained athletes and the relationship to a measure of central opioid tone.

Human beta-endorphin-like immunoactivity was measured in highly trained athletes (n = 10), alcoholics in the early phase of abstinence (n=9) and normal controls (n=15) using the Nichols Allegro immunoradiometric assay. The assay was examined for cross reactivity against related peptides, beta-lipotropin and human N-acetyl beta-endorphin. Venous blood sampling was carried out in the morning at 0900 and 1100 hours in a fasting state. Using two-way analysis of variance there was a significant effect of subject group on beta-endorphin concentration (p=0.029). Post-hoc analysis using the Bonferroni t-test showed that the source of the difference was the alcoholic group having significantly lower beta-endorphin immunoreactivity (p < 0.05). There was no difference between the controls and the athletes. There was a positive correlation between plasma beta-endorphin level at 1100 hours and the subsequent ACTH incremental response to naloxone in the group as a whole (r=0.48, p=0.004). The assay showed 100% cross reactivity with beta-lipotropin and 73% cross reactivity with N-acetyl-beta-endorphin. We conclude that alcoholics have reduced levels of beta-endorphin-like immunoactivity. While beta-endorphin is known not to cross the blood-brain barrier, levels of plasma beta-endorphin-like immunoactivity may indirectly reflect central opioid activity.

Cerebrospinal fluid and plasma beta-endorphin in combat veterans with post-traumatic stress disorder.

Opioid-mediated analgesia develops in experimental animals following traumatic stress and increased opioid-mediated analgesia has been observed in combat veterans with post-traumatic stress disorder (PTSD). These observations have led to the hypothesis that increased central nervous system (CNS) opioidergic activity exists in patients with PTSD. However, direct CNS data on opioid peptide concentrations and dynamics in patients with PTSD are lacking. We withdrew cerebrospinal fluid (CSF) via a flexible, indwelling subarachnoid catheter over a 6-h period and determined hourly CSF concentrations of immunoreactive beta-endorphin (ir beta END) in 10 well-characterized combat veterans with PTSD and nine matched normal volunteers. Blood was simultaneously withdrawn to obtain plasma for ir beta END. PTSD symptom clusters, as measured by the CAPS, were correlated with neuroendocrine data. Mean CSF ir beta END was significantly greater in patients with PTSD compared with normals and there was a negative correlation between the ir beta END and PTSD intrusive and avoidant symptoms of PTSD. No intergroup difference between plasma ir beta END was found, nor was there a significant correlation between CSF and plasma ir beta END. Immunoreactive beta-lipotropin (ir beta LPH) and pro-opiomelanocortin (irPOMC), both precursors of beta END, were much more plentiful in human CSF than was beta-endorphin itself, as has been previously reported. It remains to be determined whether the increased CNS opioid concentrations predate traumatic stress, thereby conferring a vulnerability to dissociative states and PTSD itself, or result from the trauma. The negative correlation between CSF ir beta END and avoidant and intrusive symptoms suggests that CNS hypersecretion of opioids might constitute an adaptive response to traumatic experience. Poor correlation between CSF and plasma ir beta END limits use of plasma measures to assess CNS opioid activity.

Adrenocorticotropin-producing pituitary carcinoma with liver metastasis.

We report here the extremely rare case of a twenty-eight year-old woman with a metastatic ACTH-secreting pituitary carcinoma. This is the thirteenth case to be described in the literature. Ten years ago Cushing's disease was diagnosed. After pituitary surgery, then bilateral adrenalectomy, a Nelson's syndrome appeared. The particularly extensive pituitary secondary development led to several pituitary surgical procedures, radiotherapy, and octreotide treatment. Eight years after Cushing's disease was diagnosed, liver tumors were discovered. Pathological examination and ACTH immunostaining demonstrated the secretory nature of these metastases. The lack of ectopic tumor, the LPH/ACTH equimolar ratio and a study of the plasma proopiomelanocortin derivatives by HPLC showed that the ACTH secretion originated in pituitary tissues (in situ and liver metastases). The processing of POMC seems thus to be normal in this kind of tumor and metastases. Intact POMC levels were very high, indicating an aggressive tumor, and ACTH/LPH production was paradoxically stimulated by octreotide. This case is also exceptional because of the slow development of the disease, which may be due to the complementary hepatic chemoembolization treatment.

Impaired processing of proopiomelanocortin in corticotroph macroadenomas.

The regulation and secretion of the ACTH precursors POMC and pro-ACTH were assessed directly using a 2-site immunoradiometric assay in six patients with pituitary macroadenomas (> or = 1.2 cm in diameter) and 27 patients with Cushing's disease due to a microadenoma. ACTH precursor levels were elevated in patients with macroadenomas (150-3690 pmol/L; normal range, < 5-40 pmol/L) and significantly higher than those in microadenoma patients (median, 29 pmol/L; range, 9-104 pmol/L; P < 0.001). Patients with macroadenomas also had increased ACTH precursor/ACTH ratios (15-181:1) compared with microadenoma patients (median, 5:1, range, 0.7-18.5:1; P < 0.001). ACTH precursors were unresponsive to high dose dexamethasone in patients with macroadenomas, whereas ACTH and cortisol responses varied. After CRH administration, ACTH precursors were unchanged, whereas cortisol increased significantly, suggesting the release of biologically active ACTH. This study clearly demonstrates reduced processing of POMC to ACTH in large pituitary tumors, a characteristic usually associated with tumors causing the ectopic ACTH syndrome, and provides evidence for differential regulation of ACTH precursors and ACTH by glucocorticoid and CRH. Variation in the clinical symptoms of patients with corticotroph macroadenomas may be attributable to differences in biological potency between the ACTH precursors and ACTH.

Evidence against changes in corticotroph CRF receptors in depressed patients.

Previous studies by a number have investigators have documented a decreased adrenocortotropic hormone (ACTH) and beta-lipotropin/beta-endorphin (beta-End) response to ovine corticotropin-releasing factor (oCRF) in depressed patients. Since depressed patients demonstrate higher plasma cortisol concentrations at the time of oCRF challenge, it is difficult to determine if the decreased ACTH response is due to enhanced negative feedback of cortisol on ACTH release or an alteration in CRF receptors in depressed patients. To evaluate the response to oCRF in an "open feedback loop" system, we administered metyrapone 750 mg at 4 PM and 7:30 PM, followed by administration of oCRF 0.3 microgram/kg at 8 PM in 10 normal controls and 10 depressed patients. Administration of metyrapone at this time in the circadian rhythm clamped plasma cortisol concentrations to less than 2 micrograms/dl but did not result in rebound ACTH or beta-End secretion in control subjects. In control subjects, metyrapone administration produced a 85% blockade of the cortisol response as well as a 3-fold greater beta-End response compared to administration of the same dose of oCRF without metyrapone. The 10 depressed patients and their matched controls demonstrated identical beta-End responses (integrated response for controls = 291 +/- 61, for patients = 352 +/- 86) and cortisol responses (integrated response for controls = 187 +/- 38, for patients = 206 +/- 52) to oCRF following metyrapone pretreatment. These data confirm that corticotroph CRF receptors are normal in depressed patients, and that cortisol feedback plays an essential role in the abnormal ACTH and beta-End response to oCRF in depressed patients.

Cushing's syndrome in medullary thyroid carcinoma.

Ectopic ACTH secretion is a rare cause of hypercortisolism. Induced metabolic disturbances are often serious, and the management of such patients may be difficult. We report here our experience with four medullary thyroid carcinoma (MTC) patients with distant metastases in whom an ectopic ACTH syndrome occurred. The clinical presentation was significant by the severity and the rapidity of the hypercortisolism. Diagnosis and follow-up were realized by measurements of plasma cortisol, urinary free cortisol, urinary 17-hydroxycorticosteroid, plasma ACTH, plasma LPH, serum calcitonin and carcino-embryonic antigen. Initial treatment with adrenalytic medical therapy failed to control the disease. Only bilateral adrenalectomy cured the excessive cortisol production, and for a long time despite tumor progression. In conclusion, bilateral adrenalectomy should be considered in MTC patients with Cushing's syndrome even at the stage of distant spread. In fact, with regard to the slow growth rate of most MTC's, they may survive for years.

Reliability of hormonal levels for assessing the hypothalamic-pituitary-adrenocortical system in clinical pharmacology.

Few data are available on the reliability of measurements of adrenocortical and corticotroph hormones for use in clinical pharmacology. Two placebo controlled cross-over trials in 20 normal healthy male subjects offered the opportunity to perform three repeat samplings of adrenocortical and corticotroph hormones at 1 to 5 week intervals during the placebo periods. Measurements of baseline levels of plasma, salivary and urinary cortisol, plasma adrenocorticotroph hormone (ACTH), lipotrophic hormone (LPH), beta-endorphin, post tetracosactrin levels of plasma and salivary cortisol, post corticotrophin releasing hormone (CRH)-lysine vasopressine (LVP) levels of plasma cortisol, ACTH and LPH; and post metyrapone levels of plasma cortisol and 11-deoxycortisol (compound S), ACTH, LPH, beta-endorphin were performed in the same laboratory. The reliability of the measurements was estimated by computing the intraclass correlation coefficient (R) and by using Altman-Bland graphical method. The Rs of baseline parameters varied from 0.18 (for 08.00 h salivary cortisol) to 0.55 (for 08.00 h plasma cortisol and nocturnal urinary cortisol). In contrast, parameters obtained after direct stimulation or inhibition of the producing targets were much more reliable: Rs were above 0.80 for post tetracosactrin levels of plasma and salivary cortisol, post CRH-LVP levels of plasma ACTH and LPH. The Rs were below 0.50 for post metyrapone levels of plasma 11-deoxycortisol, ACTH, LPH and beta-endorphin. The interval between sampling did not affect R estimates. These data show that peak levels of plasma cortisol and ACTH after direct stimulation are highly reliable whereas baseline and main post-metyrapone levels are not.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased evening activation of the hypothalamic-pituitary-adrenal axis in depressed patients.

OBJECTIVE: To determine whether depressed patients demonstrate hypothalamic-pituitary-adrenal (HPA) axis activation during the late afternoon and evening, a time when the HPA axis is usually quiescent in normal subjects. METHODS: We administered metyrapone, an 11-beta-hydroxylase inhibitor of cortisol synthesis, to normal controls and depressed patients between 4 and 10 PM. Metyrapone blockade of cortisol secretion would amplify any HPA axis secretion. RESULTS: In 10 normal control subjects, administration of metyrapone lowered plasma cortisol levels to a mean of 36 nmol/L. No rebound corticotropin or beta-endorphin secretion was seen in these normal controls between 4 and 10 PM, supporting the existence of a period of minimal endogenous corticotropin releasing factor drive. Compared with a group of placebo-treated depressed patients (n = 10), metyrapone-treated depressed subjects (n = 17) had significantly decreased plasma cortisol concentrations. However, in contrast to normal controls treated with metyrapone, metyrapone-treated depressed patients demonstrated rebound corticotroph secretion, particularly between 7:30 and 10 PM (P = .036 for patients vs normal controls for beta-endorphin secretion from 4:30 to 10 PM). CONCLUSION: These data support the hypothesis of increased corticotropin releasing factor drive in the evening in depressed subjects and are in agreement with the longstanding observation of "early escape" from dexamethasone suppression between 4 and 11 PM in depressed patients.