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Biomedical subjects

R Guillemin

Publications and source records attributed to R Guillemin.

At least 163 records · Page 9Linked to original sources
PubMed1977

beta-Endorphin: endogenous opiate or neuroleptic?

The opiatelike neuropeptide beta-endorphin produces a spectrum of effects that contrasts with that induced by the neuroleptic haloperidol. Rats injected intraventricularly or directly into the periaqueductal gray with beta-endorphin (0.5 to 50 micrograms) exhibited rigid immobility accompanied by the loss of righting reflex; the period of rigidity was preceded or followed (depending upon dose) by a state of hyperactivity. In contrast, no dose of haloperidol tested (0.5 to 12 milligrams per kilogram) produced rigidity, loss of righting reflex, or behavioral excitation. Furthermore, whereas animals injected with haloperidol remained stationary on a vertical grid, rats injected with beta-endorphin typically slid off the grid. Moreover, combined beta-endorphin and haloperidol treatment produced flaccidity in most animals. These results do not support the contention that this opiatelike peptide may be a naturally occurring neuroleptic.

Animals↗
PubMed1977

beta-Endorphin and adrenocorticotropin are selected concomitantly by the pituitary gland.

The opiate-like peptide beta-endorphin and adrenocorticotropin are concomitantly secreted in increased amounts by the adenohypophysis in response to acute stress or long-term adrenalectomy as well as in vitro in response to purified corticotropin releasing factor and other secretagogues. Conversely, administration of the synthetic glucocorticoid dexamethasone inhibits the secretion of both adrenocorticotropin and beta-endorphin. Thus, both hormones possess common and identical regulatory mechanisms and there may be a functional role for circulating beta-endorphin.

Adrenocorticotropic Hormone↗
PubMed1977

Presence of immunoassayable beta-endorphin in human amniotic fluid: elevation in cases of fetal distress.

Immunoassayable beta-endorphin is present in samples of amniotic fluid obtained in the last two weeks of pregnancy. Average concentration is approximately 300 pg. per milliliter. In all cases of suspected or recognized fetal distress, striking elevations of the beta-endorphin concentrations (twofold to 20-fold) were observed. The degree of elevation correlated with the degree of fetal distress.

Amniotic Fluid↗
PubMed1977

Negative naloxone effects in schizophrenic patients.

On the basis of the hypothesis that the opiate-like neuropeptides, such as beta-endorphin, may be involved in the etiology of schizophrenic symptoms, naloxone 1,2 mg and placebo were administered intravenously to 8 schizophrenic patients, using a double-blind, crossover design. Naloxone was not found to be different from placebo in effecting schizophrenic symptoms, including hallucinations and delusions.

Adult↗