The synthesis and opiate activity of β-endorphin

Li, Choh Hao; Lemaire, Simon; Yamashiro, Donald; Doneen, Byron A.

doi:10.1016/0006-291x(76)90243-6

Cited by 138 publications

(37 citation statements)

References 17 publications

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“…Synthetic P-endorphin (sheep) was prepared in our laboratory (Lemaire, Berube, Derome, Lemaire, Magnan, Regoli & St-Pierre, 1978) as described by Li, Lemaire, Yamashiro & Doneen (1976) (Lord et al, 1977).…”

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confidence: 99%

Rat Vas Deferens: A Specific Bioassay for Endogenous Opioid Peptides

Lemaire

Magnan

Regoli

1978

British J Pharmacology

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111

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The electrically‐evoked contractions of the rat vas deferens were selectively inhibited by β‐endorphin, the preparation being much less sensitive to enkephalins and narcotic analgesic drugs. However, introduction of D‐Ala in position 2 of [Leu]‐enkephalin enhanced the activity of the opioid peptide to the order of that of β‐endorphin. It is concluded that the rat vas deferens preparation constitutes a specific bioassay for endogenous opioid peptides and related compounds.

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confidence: 99%

Rat Vas Deferens: A Specific Bioassay for Endogenous Opioid Peptides

Lemaire

Magnan

Regoli

1978

British J Pharmacology

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111

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“…Reyes, Calif). (3-Endorphin was synthesized as previously described (2). Naloxone hydrochloride was purchased from Endo Laboratories (Garden City, N.Y.).…”

Section: Methodsmentioning

confidence: 99%

“…(3-Endorphin, an untriakontapeptide isolated from camel pituitary glands (1), has been synthesized (2) and shown to possess opiate-like activity in receptor binding assays and in the guinea pig ileum bioassay (1)(2)(3). The analgesic activity of the synthetic peptide has been tested in rodents by intracerebral injection and found to be 18-33 times more potent than morphine, when compared on a molar basis, as shown by the tail-flick test, the hot plate test, and the acetic acid-induced writhing method in mice and the ice water-induced shake response in rats (4).…”

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confidence: 99%

beta-Endorphin: behavioral and analgesic activity in cats.

Meglio

Hosobuchi

Loh

et al. 1977

Proc. Natl. Acad. Sci. U.S.A.

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fl-fEndorphin has been.shown to possess potent behavioral and antinociceptive activities when administered intraventricularly in cats. On a molar.basis, P-endorphin is times more ptent than morphine and its actions are blocked by the speciricopiate antagonist, naloxone.(3-Endorphin, an untriakontapeptide isolated from camel pituitary glands (1), has been synthesized (2) and shown to possess opiate-like activity in receptor binding assays and in the guinea pig ileum bioassay (1-3). The analgesic activity of the synthetic peptide has been tested in rodents by intracerebral injection and found to be 18-33 times more potent than morphine, when compared on a molar basis, as shown by the tail-flick test, the hot plate test, and the acetic acid-induced writhing method in mice and the ice water-induced shake response in rats (4). In addition, fl-endorphin has also been tested in mice via intravenous administration and found to be 3-4 times more potent than morphine, on a molar basis, in its analgesic effect (5). The present study was undertaken to determine the analgesic and behavioral effects of the peptide administered intraventricularly in the awake, unrestrained cat. showed an alteration of their behavior as follows: (I) fine tremors of the head accompanied by sudden quick head movements; MATERIALS AND METHODS Met(ii) mild excitation; (fii) fixation of eyes into space or on an object (cats barely responded to external noises-shaing of the cage, tapping of the floor, calling, etc.-and were hardly distracted from their apparent fixation on phantom objects; they changed their direction of gaze from time to time, but they always appeared to have "visual hallucinations"); and (iv) pupillary dilatation varied in intensity from one cat to the other, although fixation of eyes into space was prominent in all cats tested. The altered behavior was evident for about 1 hr, after which the animals appeared to return to their normal behavioral state. In none of the animals was intravenrtricular injection of 12.5 MAg of (3-endorphin followed by a significant alteration in JOR or response to pinch test.Intraventricular injection of 25MAg of fl-endorphin induced, within 15-20 min, alteration of behavior in all cats as described above. In general, the alterations were somewhat more pronounced and. longer lasting than those seen after adminiation of 12.5 Mug of the peptide. In all animals the intraventricular administration of (3-endorphin was followed by a significant rise of the threshold for the JOR. Such an increase in threshold was always concomitant with or came after the first signs of behavioral change. The maximal increase of the JOR threshold was reached about 60 min after peptide administration (Fig.

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“…Ph-EP (14), camel /-EP (,8c-EP) (15), ostrich /3-EP (,j%5-EP) (16), turkey R-EP (Iu-EP) (17), IAh-N`~-AcEP (14), /3h-EP- (18), Ph-EP-(2-31) (18), Ph-EP-(21-31) (18), /3h-EP-(28-31) (18), 13h-EP-(1-27) (19), /3h-[Gly ]EP (20), Ph-[Gln8,Gly31]EP-Gly-Gly-NH2 (21) were synthetic products.…”

Section: Methodsmentioning

confidence: 99%