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Biomedical subjects

R Guillemin

Publications and source records attributed to R Guillemin.

At least 145 records · Page 8Linked to original sources
PubMed1979

Stimulation of human periaqueductal gray for pain relief increases immunoreactive beta-endorphin in ventricular fluid.

Immunoreactive beta-endorphin was measured in the ventricular fluid of six patients with chronic pain. Stimulation of the periaqueductal gray matter in three patients with pain of peripheral origin resulted in significant increases (50 to 300 percent) in the concentration of ventricular immunoreactive beta-endorphin. In three other patients suffering deafferentation dysesthesia, stimulation of the posterior limb of the internal capsule did not alter the concentration of this peptide. These results provide evidence of the release of human immunoreactive beta-endorphin in vivo and suggest that naloxone-reversible pain relief achieved by stimulation of the periaqueductal gray matter may be in part mediated by the activation of beta-endorphin-rich diencephalic areas.

Aged↗
PubMed1979

Opioid peptides and alpha-melanocyte-stimulating hormone in genetically obese (ob/ob) mice during development.

Compared to littermate controls (C57BL/6J ob/?), body weights of genetically obese (ob/ob) mice are significantly higher at 1-6 months of age; the greatest percentage weight gain of the ob/ob group occurs during the first 3 months of life. Levels of pituitary immunoreactive beta-endorphin and immunoreactive alpha-melanocyte-stimulating hormone are also significantly elevated in ob/ob animals compared to controls. However, these pharmacological differences only emerge at 4-6 months of age--3 months after the appearance of obesity. High levels of immunoreactive endorphin in the pituitary are, therefore, more likely to be a consequence than a cause of obesity. Furthermore, numerous other neurologic abnormalities, which may or may not play a role in the obesity syndrome, are evident in ob/ob mice. Compared to controls, ob/ob total brain, hypothalamus, and pituitary weights are 11%, 16%, and 23% less, respectively. Levels of immunoreactive Leu5-enkephalin in pars nervous are also 200% higher in ob/ob mice; this increase is apparent at 1-6 months of age and is highly correlated with changes in body weight.

Aging↗
PubMed1979

Dried Staphylococcus aureus as a rapid immunological separating agent in radioimmunoassays.

A rapid (less than or equal to 60 seconds) immunological separation of antigen-antibody complexes from free antigen has been developed in radioimmunoassays (RIAs) of luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL) and beta-endorphin by using suspensions of dried Staphylococcus aureus rich in protein-A. In the systems tested parallel dose-response curves were obtained for protein-A and second antibody precipitations. The sensitivity of the protein-A method is equal to or higher than that of second antibody method. Tissue culture medium and serum hormone levels measured with RIAs using protein-A are similar to those detected with double antibody methods. The technique may be of general use in all RIAs utilizing antisera from species whose IgG are known to be bound by protein-A.

Antigen-Antibody Complex↗
PubMed1978

beta-Endorphin induces nonconvulsive limbic seizures.

The endogenous opioid peptide, beta-endorphin, induces nonconvulsive limbic epileptiform activity when administered intraventricularly to rats. Epileptiform activity is elicited by beta-endorphin in doses that are devoid of analgesic or behavioral signs. Equimolar intraventricular doses of morphine or of the enkephalin analog [DAIa2,Met5]enkephalin-NH2 fail to elicit this limbic epileptiform activity. These observations, together with the recent immunohistochemical localization of beta-endorphin to midline limbic structures, suggest that beta-endorphin may have an important role in the regulation of limbic excitability.

Animals↗
PubMed1978

Neurons containing beta-endorphin in rat brain exist separately from those containing enkephalin: immunocytochemical studies.

Well-characterized antisera to porcine beta-endorphin were used to localize immunoreactive sites in cryostat sections of formaldehyde-fixed rat brain by indirect immunohistochemistry. Specificity was established by absorption of immune sera with synthetic peptide fragments. Specific immunoreactivity was localized to neuronal perikarya in the basal tuberal hypothalamus, and to varicose nerve fibers which were distributed to midline nuclear areas throughout the diencephalon and anterior pons. These patterns of reactivity were unaffected by preabsorption of the immune sera with millimolar concentrations of Met5- or Leu5-enkephalin or alpha-endorphin. The beta-endorphin immunoreactive structures were morphologically separate from those cells and fibers reported to react with antisera to the enkephalins. One anti-beta-endorphin serum gave additional immunoreactivity with myelinated axons in limbic cortical zones; when absorbed with purified rat myelin basic protein, only the specific patterns of immunoreactivity remained. Thus, discrete beta-endorphin-containing neuronal circuits exist in rat brain and are anatomically distinguishable from enkephalin-containing nerve cell and fiber pathways.

Animals↗
PubMed1978

In vitro release of [5-methionine]enkephalin and [5-leucine]-enkephalin from the rat globus pallidus.

Endogenous [5-methionine]enkephalin (Metenkephalin) and [5-leucine]enkephalin (Leu-enkephalin) are released from perfused slices of rat globus pallidus by increased K(+) in a Ca(2+)-dependent manner. Tissue perfused for 40 min contained only 26% of the Met-enkephalin and 44% of the Leu-enkephalin found in the freshly dissected tissue. After perfusion, the mean (+/-SEM) ratio (wt/wt) of Met-enkephalin to Leu-enkephalin was 3.4 +/- 0.2 compared with 5.8 +/- 0.2 in the fresh tissue. The degradation of trace amounts of synthetic [(3)H]enkephalins in the perfusing medium during stimulated release seems to reflect the accelerated degradation of enkephalin released from the tissue: 63% of the Met-enkephalin and 23% of the Leu-enkephalin were degraded in a medium containing bacitracin (30 mug/ml). The mean ratio (wt/wt) of the Met-enkephalin to the Leu-enkephalin recovered after release by exposure of slices to 50 mM K(+) was 2.7 +/- 0.3. When perfusates were corrected for degradation, this ratio increased to about 5.5 which is higher than that found in the perfused tissue. The differences in release, tissue loss, and catabolism of the two enkephalins may be reflecting differences in the metabolic systems operating on the pentapeptides, but this interpretation will have to be validated by in vivo release experiments. In any event these observations strongly suggest that both enkephalins can be considered candidate neurotransmitters in the rat globus pallidus.

Animals↗
PubMed1978

Beta-lipotropin and endorphins: implications of current knowledge.

Evidence that the endorphins, metabolites of the pituitary hormone beta-lipotropin, profoundly affect mood and behavior, are secreted with ACTH in response to stress, and may act as neurotransmitters in the GI tract, suggests that they play an important role in CNS homeostasis. The fact that these peptides are synthesized in the GI tract as well as the brain casts new light on CNS-endocrine-environmental interrelationships.

Adrenocorticotropic Hormone↗
PubMed1978

Immunoreactive endorphins, lipotropins and corticotropins in a human nonpituitary tumor: evidence for a common precursor.

The immunoreactive (RIA), ACTH, LPH, alpha endorphin (alpha End) and beta End in an extract of a human pancreatic islet cell carcinoma causing the ectopic ACTH syndrome were assayed after gel exclusion chromatography. In addition to "big", "intermediate" and "little" ACTHs, beta lipotropin (beta LPH) and gamma LPH, the eluate fractions contained RIA-alpha End and -beta End. The major RIA-beta End component appeared to be h beta LPH, which has beta End as its carboxy-terminus, but significant concentrations of a component that coeluted with synthetic p beta End were also found. Small amounts of RIA-alpha End were found in two peaks, one that may have represented 1-76 h beta LPH, with alpha End as its carboxy-terminus, and one probably representing alpha End itself. RIA-ACTH, -LPH and -beta End were found in the void volume fractions. Thus, a human nonpituitary tumor that produced ACTH and LPHs also produced endorphins, all perhaps deriving from a common precursor.

Adenoma, Islet Cell↗
PubMed1978

Demonstration by immunoperoxidase histochemistry of calcitonin in the anterior lobe of the rat pituitary.

We have demonstrated by a specific immunoperoxidase procedure the presence of calcitonin-containing cells in the rat pituitary gland. These cells are widely distributed throughout the anterior lobe and seem to constitute the entire population of cells of the intermediate lobe. No such cells were seen in the posterior lobe. The presence of calcitonin-containing cells in the pituitary provides novel implications about the physiological significance of this hormone.

Animals↗