Lorraine McLoughlin

INCREASED β-ENDORPHIN BUT NOT MET-ENKEPHALIN LEVELS IN HUMAN CEREBROSPINAL FLUID AFTER ACUPUNCTURE FOR RECURRENT PAIN

Low-frequency electroacupuncture effectively alleviated recurrent pain in 10 patients. Basal levels of beta-endorphin and met-enkephalin in the lumbar cerebrospinal fluid (CSF) of these patients were not different from those in pain-free control subjects. After electroacupuncture in the patients with pain CSF beta-endorphin levels rose significantly in all subjects, but met-enkephalin levels were unchanged. These results suggest that the analgesia observed after electroacupuncture in patients with recurrent pain may be mediated by the release into the CSF of the endogenous opiate, beta-endorphin.

Familial glucocorticoid deficiency associated with point mutation in the adrenocorticotropin receptor

Familial glucocorticoid deficiency is an uncommon disorder that appears to be due to congenital insensitivity or resistance to adrenocorticotropin (ACTH), and is usually inherited in an autosomal recessive pattern. We investigated the DNA base sequence in a family with this condition by polymerase chain reaction amplification of DNA with pairs of primers that span the ACTH-receptor domain. The affected male proband showed a single base mutation, ser74-->ile, in the sequence coding for the second transmembrane domain of the ACTH receptor. A similar defect was found in an affected sister, a normal sequence in an unaffected brother, and both alleles in each parent. This is only the second clinical disorder associated with a GTP-binding-protein-linked hormone-receptor mutation.

ACUPUNCTURE IN HEROIN ADDICTS: CHANGES IN MET-ENKEPHALIN AND β-ENDORPHIN IN BLOOD AND CEREBROSPINAL FLUID

In heroin addicts showing features of heroin withdrawal basal beta-endorphin levels were elevated in both blood and cerebrospinal fluid (CSF) and did not change during electroacupuncture, although this therapy suppressed the clinical features of withdrawal. Met-enkephalin levels were not elevated in blood or CSF before treatment. However, successful electroacupuncture was associated with a rise in CSF met-enkephalin levels in all patients studied, although concentrations in blood did not alter.

β-ENDORPHIN IN HUMAN CEREBROSPINAL FLUID

beta-endorphin is a brain peptide with potent morphine-like activity structurally related to the anterior pituitary hormone beta-lipotrophin (beta-L.P.H.). We have developed a radioimmunoassay for human beta-endorphin in plasma and cerebrospinal fluid (C.S.F.). Since the antiserum also reacts with beta-L.P.H., beta-endorphin was distinguished by using a second antiserum which measures beta-L.P.H. alone. With these two immunoassay systems and gel chromatography, we found beta-endorphin in all 20 C.S.F. samples tested at a concentration always higher than, but with no other relationship to, that in plasma. beta-endorphin was found in C.S.F. of patients who had hypopituitarism and undetectable plasma-beta-endorphin, suggesting that it is synthesized in the brain rather in the pituitary.

Expression of pro-opiomelanocortin gene and quantification of adrenocorticotropic hormone-like immunoreactivity in human normal peripheral mononuclear cells and lymphoid and myeloid malignancies.

Using Northern blotting with a human genomic DNA probe for the pro-opiomelanocortin (POMC) gene, we have shown specific mRNA in normal human peripheral mononuclear cells (PBMC); the presence of specific mRNA was also observed in a T lymphocyte cell line derived from a patient with lymphoma. We then demonstrated that PBMC translate the message into protein. Thus, using a radioimmunoassay with an antibody for ACTH, a median of 29 pg of ACTH-like immunoreactivity (ACTH-LIR) was found in 10(7) PBMC. ACTH-LIR was also detected in seven different cell lines derived from patients with lymphoid and myeloid malignancies, two of them JM and U937 showing the highest values 135 and 108 pg/10(7) cells, respectively. The chromatographic characterization of this ACTH-LIR showed, at least, three molecular forms of immunoreactive ACTH with molecular weights of the order of 31,000 POMC, 22,000 ACTH, and 4,500 ACTH, in addition to high-molecular-weight material (greater than 43,000). We conclude that PBMC produce ACTH-LIR which may act as a paracrine immunomodulator in a similar way to lymphokines and/or may signal the adrenal gland to secrete glucocorticoids.

Hyperactivity of the hypothalamo‐pituitary‐adrenal axis in obesity: a study of ACTH, AVP, β‐lipotrophin and Cortisol responses to insulin‐induced hypoglycaemia

OBJECTIVE The purpose of this study was to determine whether alterations in the hypothalamo‐pituitary‐adrenal axis and arginine vasopressin secretion, which have been associated with animal obesity, also occur in man.

DEVELOPMENT OF A RADIOIMMUNOASSAY FOR AN AMINO‐TERMINAL PEPTIDE OF PRO‐OPIOCORTIN CONTAINING THE γ‐MSH REGION: MEASUREMENT AND CHARACTERIZATION IN HUMAN PLASMA

A radioimmunoassay has been developed for the N‐terminal region of human pituitary pro‐opiocortin (N‐POC), the common precursor protein of ACTH and β‐LPH, using an antiserum which recognizes residues near the γ‐MSH region. The concentrations of greater than 300 ng/l of immunoreactive peptide were determined in unextracted human plasma, the relative molecular mass of the reacting fragments corresponding to a seventy‐seven amino acid glycoprotein. The concentrations of immunoreactive N‐POC peptides were correlated with those of ACTH in plasma obtained from patients with various disorders of the hypothalamic‐pituitary‐adrenal axis.

Effect of Metyrapone on the Pituitary-Adrenal Axis in Depression Relation to Dexamethasone Suppressor Status

It has been suggested that the well-documented hypercortisolaemia found in a proportion of patients with severe depression occurs either in response to excessive secretion of corticotrophin-releasing hormone-41 (CRH-41) from the hypothalamus, or as a consequence of up-regulation of pituitary CRH-41 receptors. The attenuation of the normal ACTH response to CRH-41 in these subjects is thought to result from inhibition of corticotrophin secretion by elevated cortisol levels. We tested these hypotheses by examining ACTH responses to metyrapone, an 11 beta-hydroxylase inhibitor which blocks the formation of cortisol, followed by CRH-41 in 15 severely depressed in-patients diagnosed according to DSM-IIIR criteria. Patients were assigned to two groups according to their response to overnight administration of 1 mg dexamethasone: suppressors (8) and nonsuppressors (7). A third group consisted of 6 healthy matched controls. Metyrapone 750 mg was given 4-hourly for 24 h and samples were taken for cortisol and ACTH. Six of the original 15 patients (3 from each group) were given a bolus dose of 100 micrograms human CRH-41 intravenously after 24 h of metyrapone, and ACTH levels were measured over 2 h. Falls in circulating cortisol in response to metyrapone were similar in all three groups. However, we found exaggerated rises in ACTH amongst the nonsuppressors, as compared to the suppressors and the control group, after metyrapone.(ABSTRACT TRUNCATED AT 250 WORDS)

CRF-41 Stimulates the Release of β-Lipotrophin and β-Endorphin in Normal Human Subjects

A prompt rise in circulating immunoreactive N- and C-terminal lipotrophin (LPH) accompanied the increase in ACTH when 100 µg CRF-41 was given to 6 normal male subjects. Chromatography of the basal and peak 15-min values showed that there was an equimolar increase in β-LPH and β-endorphin. to cause parallel release of ACTH, β-endorphin and β-LPH from the pro-opiocortin precursor.

β-ENDORPHIN AND β-MSH IN HUMAN PLASMA

The aim of this study was to establish whether or not a peptide with chromatographic and immunological properties of β‐endorphin exists in human plasma. Using direct chromatography under conditions designed to minimize generation of β‐endorphin and β‐MSH from β‐LPH, we invariably found a peptide with β‐endorphin immunoreactivity eluting in the position of βh‐endorphin on gel chromatography in samples of plasma from patients with elevated ACTH and LPH levels. β‐MSH was only found in the plasma of one patient with the ectopic ACTH syndrome.