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Endorphins in schizophrenia: hemodialysis/hemoperfusion are ineffective in clearing beta-Leu5-endorphin and beta-endorphin from human plasma.

Beta-Leu5-endorphin, a relative of "normal" beta-endorphin in which leucine is substituted for methionine at position 5 of the latter, has previously been found in high concentrations in the dialysate of schizophrenics. Its removal from plasma by means of hemodialysis has been claimed to relive the symptoms of schizophrenia. Using a highly sensitive radioimmunoassay of equal sensitivity to beta-endorphin and beta-leu5-endorphin, we have compared the plasma immunoreactivity of three schizophrenic patients befofe and after performance of their first session of membrane hemoperfusion. As compared to normal subjects, plasma beta-endorphin-like immunoreactivity was not greatly elevated in the schizophrenic patients before hemoperfusion.However, instead of the expected decrease, a consistent increase in the plasma levels of immunoreactive beta-endorphin was detected after hemoperfusion. In vitro experiments in which two different membranes and hemodialysis as well as hemoperfusion were used, revealed that synthetic beta-leu5-endorphin (and beta-endorphin) from human plasma was not cleared with any of these methods. This finding is inconsistent with the hypothesis that the claimed therapeutic effects of hemodialysis in schizophrenics are due to the removal of a beta-endorphin-like material from the plasma. Consequently, it seems to be unprobable that high concentrations of beta-leu5-endorphin occur in the dialysate or ultrafiltrate of schizophrenics.

Adult

Endorphins in chronic pain. I. Differences in CSF endorphin levels between organic and psychogenic pain syndromes.

A series of 37 patients with chronic pain was investigated with regard to neurologic and psychiatric variables. Twenty of the patients were classified as having mainly organic (= somatogenic) pain syndromes while 17 patients were rather suffering from psychogenic pain syndromes. Samples of lumbar cerebrospinal fluid (CSF) were obtained from the patients and analyzed for the presence of opiate receptor-active material, here called endorphins. Patients classified as having mainly organic pain syndromes were found to have significantly lower endorphin levels than patients with predominantly psychogenic pain syndromes. In the total group of patients as well as in the two subgroups, there was a significant correlation between CSF endorphin levels and the depth of depressive symptomatology as reported by the patients. On the other hand, there was no correlation between CSF endorphin levels and extent of anxiety or motor retardation. It is concluded that CSF endorphins reflect central processes involved in chronic pain syndromes.

Adult

Presence of immunoreactive beta-endorphin in normal human plasma: a concomitant release of beta-endorphin with adrenocorticotropin after metyrapone administration.

To elucidate whether or not beta-endorphin exists in plasma of normal subjects, plasma extracts obtained before and after metyrapone administration were subjected to gel exclusion chromatography, and fractions obtained were assayed by a sensitive radioimmunoassay for beta-endorphin. The basal plasma level of beta-endorphin was 5.8 +/- 1.1 pg/ml (mean +/- SE, n = 5), which rose significantly to the level of 48.9 +/- 3.8 pg/ml after a single oral dose (30 mg/kg of body wt) of metyrapone administration (P less than 0.001). Plasma ACTH levels also increased from the mean basal level of 73 +/- 4 pg/ml to 269 +/- 41 pg/ml after metyrapone administration. These results indicate that beta-endorphin, distinct from beta-lipotropin, exists in normal human plasma and that it is released from the pituitary concomitantly with ACTH.

Adrenocorticotropic Hormone

ACTH, beta-LPH and beta-endorphin in pituitary adenomas of the patients with Cushing's disease: activation of beta-LPH conversion to beta-endorphin.

ACTH, beta-lipotropin (beta-LPH) and beta-endorphin concentrations were determined in pituitary adenomas of the patients with Cushing's disease. Immunoreactive ACTH and beta-endorphin were present in high concentrations and essentially equimolar amounts in pituitary adenomas. beta-LPH conversion to beta-endorphin was activated in pituitaries associated with ACTH/beta-LPH producing adenomas. Immunoreactive ACTH and beta-endorphin concentrations were markedly suppressed in the surrounding tissues.

Adenoma

[Endorphins, hypothalamic and neurohypophysial peptides with morphinomimetic activity: isolation and molecular structure of alpha-endorphin].

From a crude extract of Porcine neurohypophysis-hypothalamus we have isolated several peptides called endorphins which mimic opiated in a classical bioassay for morphine. Similarly they bind to the stereospecific synaptosomal opiates receptors of Rat brain in competition to 3 H-etorphine. The primary structure of alpha-endorphin is H-Tyr-Gly-Gly-Phe-Met-Thr-Ser-Glu-Lys-Ser-Gln-Thr-Pro-Leu-Val-Thr-OH. Met-enkephalin is the N-terminal pentapeptide of alpha-endorphin. Alpha-endorphin has the same sequence as that of the fragment TYR 61 to Thr 76 of the beta-lipotropins.

Amino Acid Sequence

Systemic administration of Met-enkephalin, (D-Ala2)-Met-enkephalin, beta-endorphin, and (D-Ala2)-beta-endorphin: effects on eating, drinking and activity measures in rats.

Rats were given four daily, interperitoneal injections (80 micrograms/kg) of Met-enkephalin, (D-Ala2)-Met-enkephalin-NH2, beta-endorphin, (D-Ala2)-beta-endorphin or the diluent (0.9% NaCl acidified to, 0.01 M with acetic acid). Animals were subsequently tested for food and water inake and activity. Met-enkephalin injections did not affect any of the measures but its (D-Ala2) analog reduced food intake and some of the activity measures in a complicated way. beta-Endorphin injections did not affect food or water intake; in familiar situations these animals were less active while novel situations seemed to potentiate activity. The (D-Ala2) analog reduced wheel running over 24 hours.

Animals

[Antigenic determinants of beta-LPH, beta-MSH, alpha-endorphin, ACTH and alpha-MSH revealed by anti-beta-endorphin in neurons of the human infundibular nucleus].

Comparison of adjacent serial sections of the tubero-infundibular region of Human adult hypothalamus demonstrates that the same perikarya, axons and terminals are stained both with anti-beta-endorphin and anti 17-39 ACTH antisera. The most immunoreactive of these neurons are also revealed with anti alpha-endorphin, anti alpha and beta-MSH, anti-1-24 ACTH and anti beta-LPH. These results suggest that neurons of the infundibular nucleus can store and probably secrete peptide similar to propiocortin or fragment(s) of this molecule.

Adrenocorticotropic Hormone

Steps involved in the processing of common precursor forms of adrenocorticotropin and endorphin in cultures of mouse pituitary cells.

The initial steps in the processing of the common precursor to adrenocorticotropin (ACTH) and endorphin in mouse pituitary tumor cells (AtT-20) have been investigated. Three forms of the precursor have been resolved by sodium dodecyl sulfate (NaDodSO4)-polyacrylamide gel electrophoresis with apparent molecular weights of 29 000 (29K ACTH-endorphin), 32 000 (32K ACTH-endorphin) and 34 000 (34K ACTH-endorphin). These forms have a similar peptide backbone, but their carbohydrate content differs. In particular, a tryptic glycopeptide has been observed in 32K ACTH-endorphin which is not present in 29K ACTH-endorphin and has been identified as the tryptic peptide containing the alpha(22--39) sequence of ACTH. Similar heterogeneity in carbohydrate has been observed in some of the smaller molecular weight forms of ACTH which are resolved by NaDodSO4 gel electrophoresis. Pulse chase and continuous labeling studies using radioactive amino acids and sugars suggest that the 29K ACTH-endorphin is converted to 32K and 34K ACTH-endorphin by the addition of carbohydrate. The glycopeptide and pulse chase studies suggest that 29K ACTH-endorphin is at a branch point in the processing pathways. It can either be converted to 4.5K ACTH by proteolytic processing or to 32K ACTH-endorphin by the further addition of carbohydrate. The 32K ACTH-endorphin can then be converted to 13K ACTH, the glycosylated form of 4.5K ACTH (Eipper, B.A., & Mains,, R.E. (1977) J.Biol. Chem.252, 882), by proteolytic processing. A comparison of the distribution of the different molecular weight forms of ACTH and endorphin in mouse pituitary extracts and in the mouse pituitary tumor cells reveals that the pituitary contains all of the forms of ACTH and endorphin seen in the tumor cells, including the three forms of the ACTH-endorphin precursor. However, the molecular weight distribution of the forms in the anterior lobe is very different from that in the intermediate lobe of mouse pituitary.

Adrenocorticotropic Hormone