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Biomedical subjects

J Rossier

Publications and source records attributed to J Rossier.

At least 199 records · Page 11Linked to original sources
PubMed1980

Probable precursors of [Leu]enkephalin and [Met]enkephalin in adrenal medulla: peptides of 3-5 kilodaltons.

Adrenal chromaffin granules contain at least 10 peptides, ranging in size from 3 to 5 kilodaltons, that yield, upon digestion with trypsin, peptides that show specific binding to opiate receptors. All are distinctly different from beta-endorphin. Two of these peptides have been purified to homogeneity and subjected to chemical analysis. One is apparently a [Met]enkephalin precursor containing two copies of the [Met]enkephalin sequence. The other peptide contains both [Leu]enkephalin and [Met]enkephalin sequences and is presumably a common precursor of the two forms of enkephalin.

Adrenal Medulla↗
PubMed1980

Distribution of opioid peptides in the pituitary: a new hypothalamic-pars nervosa enkephalinergic pathway.

The distribution of the endorphins, beta-endorphin and enkephalin (Met5-enkephalin and Leu5-enkephalin), was determined in the pars distalis, intermedia, and nervosa of the rat pituitary using both immunocytochemical and radioimmunological methods. Immunoreactive (ir) beta-endorphin was found in pars distalis and pars intermedia. On gel filtration of the pars distalis extracts, beta-endorphin immunoreactivity was eluted in three peaks corresponding to pro-opiocortin (5%), beta-lipotropin (75%), and beta-endorphin (20%). beta-Endorphin was the only component in the pars intermedia. Enkephalin was found in high amount in the pars nervosa. A new enkephalinergic hypothalamic-pars nervosa pathway was observed. Dehydration experiments on normal rats and analysis of the genetically polyuric Brattleboro rat suggest that this enkephalinergic pathway may modulate neurohypophyseal neurosecretion.

Animals↗
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

Isolation of the opioid heptapeptide Met-enkephalin [Arg6,Phe7] from bovine adrenal medullary granules and striatum.

Bovine adrenal chromaffin granules have been shown to contain, in addition to Met-enkephalin and Leu-enkephalin, at least three small peptides with opiate receptor activity. One of these adrenal peptides has been purified to homogeneity and its sequence was shown to be Met-enkephalin-[Arg6,Phe&]. This heptapeptide was also found in beef striatal extracts in amounts comparable to those of Leu-enkephalin.

Adrenal Medulla↗
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↗
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↗
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↗