Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined the influence of imipramine, a traditional tricyclic antidepressant, on the binding to serotonin (5-HT)(2) receptors and levels of 5-HT(2A)-receptor mRNA in the frontal cortex of rats treated with adrenocorticotropic hormone (ACTH). Chronic treatment with ACTH significantly increased the binding of [(3)H]-ketanserin to 5-HT(2) receptors and the expression of 5-HT(2A)-receptor mRNA in the frontal cortex. However, it did not alter the concentration of 5-HT or 5-hydroxyindole acetic acid. The effect of chronic ACTH treatment on 5-HT(2) receptor and 5-HT(2A)-receptor mRNA levels was not altered by the chronic administration of imipramine. Also, imipramine did not affect the hyperfunction of 5-HT(2A) receptors caused by chronic ACTH treatment. These findings suggest that chronic treatment with ACTH acts to increase 5-HT(2A)-receptor synthesis through increased gene transcription, without modulating presynaptic serotonergic neurotransmission.
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PMID:Increased DOI-induced wet-dog shakes in adrenocorticotropic hormone-treated rats are not affected by chronic imipramine treatment: possible involvement of enhanced 5-HT(2A)-receptor expression in the frontal cortex. 1818 23

A method using capillary liquid chromatography-triple-stage mass spectrometry (LC-MS(3)) to determine endogenous opioid peptides in microdialysis samples collected in vivo was developed, validated, and applied to measurements in the rat striatum. Peptides in dialysate rapidly degraded when stored at room temperature or -80 degrees C. Adding acetic acid to a final concentration of 5% stabilized the peptides for 5 days allowing storage of fractions and off-line measurements which proved more convenient and reliable than previously used on-line methods. Study of the effect of dialysis flow rate from 0.2 to 2 microL/min and column inner diameter (i.d.) from 25 to 75 microm on the relative signal obtained for peptides revealed that lowest flow rates and smallest column i.d. gave the highest relative signal. The method was tested for 10 different neuropeptides and limits of detection (LODs) were from 0.5 to 60 pM (4 microL samples) for most. beta-Endorphin had an LOD of 5 nM when detected directly, but it could be quantitatively determined by detecting a characteristic peptide produced by tryptic digestion with an LOD of 3 pM. This approach may prove useful for other large neuropeptides as well. The method was used to determine met-enkephalin, leu-enkephalin, dynorphin A(1-8), and beta-endorphin in vivo. Endomorphin 1 and 2 were below the detection limit of the method in vivo. Quantitative determination of leu-enkephalin using external calibration was verified by standard addition experiments. The improvements over previous approaches using capillary LC-MS(n) make in vivo neuropeptide monitoring more practical and feasible for a variety of neuropeptides.
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PMID:Practical aspects of in vivo detection of neuropeptides by microdialysis coupled off-line to capillary LC with multistage MS. 1919 60

The processing pathway of enkephalins along the sympathetic neuron was studied. While in vasa deferentia terminal parts of peripheral sympathetic neurons are found, sympathetic ganglia contain the cell bodies of these neurons. Biochemical evidence was obtained for the colocalization of met-enkephalin and noradrenaline in large dense-cored vesicles of sympathetic neurons of bovine vasa deferentia and bovine ganglia stellata. Acetic acid extracts of these tissues were analysed by a combination of chromatography, proteolytic digestion with trypsin and carbonxypeptidase B and specific radioimmunoassays. High molecular weight species of enkephalin containing peptides were detected in ganglia stellata. In contrast with the ganglia, only low molecular weight enkephalin containing peptides could be found in the vasa deferentia. When these peptides extracted from vasa deferentia were further analysed on reversed phase fast protein liquid chromatography, the met- to leu-enkephalin ratio was found to be 4.8 to 1, which is close to the 4 to 1 ratio found in the proenkephalin precursor. After digestion with trypsin and carboxypeptidase B, met-enkephalin immunoreactivity appeared in fractions probably containing met-enkephalin-arg-6-phe-7, met-enkephalin-arg-6-gly-7-leu-8 and peptide E.
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PMID:Enkephalin containing peptides in the peripheral sympathetic nervous system. 2050 Nov 77


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