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Annals of the New York Academy of... 1987
Topics: AIDS-Related Complex; Acquired Immunodeficiency Syndrome; Animals; Enkephalin, Methionine; Humans; Immunotherapy; Killer Cells, Natural; Neoplasms; T-Lymphocytes
PubMed: 3496822
DOI: 10.1111/j.1749-6632.1987.tb35753.x -
Journal of Medicinal Chemistry Jun 2006A series of new peptides (8-25) containing different unnatural amino acids of the adamantane type (1-6), was synthesized. Possible cytotoxic activity on human cervical...
A series of new peptides (8-25) containing different unnatural amino acids of the adamantane type (1-6), was synthesized. Possible cytotoxic activity on human cervical adenocarcinoma (HeLa), larynx carcinoma (HEp-2), colon carcinomas (HT-29, Caco-2), poorly differentiated cells from lymph node metastasis of colon carcinoma (SW-620), mammary gland adenocarcinoma (MCF-7), and melanoma (HBL) cells were tested by the MTT assay. The results were compared with the effect of methionine-enkephalin (Tyr-Gly-Gly-Phe-Met, or opioid growth factor, OGF), and its shorter N-terminal fragments. Peptide analogues containing C(alpha alpha)-dialkylated glycine (Aaa1, 1) or C(alpha)-alkylated glycine (Aaa2, 2) amino acid residues showed antitumor activity against melanoma, larynx carcinoma, colon carcinomas, and colon metastasis cell lines in vitro. The pentapeptide Tyr-(R,S)-Aaa2-Gly-Phe-Met (18) was the most effective analogue especially against the most antitumor drug-resistant cell lines HEp-2 and SW-620. Apoptosis as a mode of cell death was confirmed in these tumor cells after exposure to pentapeptide 18.
Topics: Adamantane; Amino Acids; Antineoplastic Agents; Cell Line; Cell Line, Tumor; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Enkephalin, Methionine; Humans; Hydrophobic and Hydrophilic Interactions; Oligopeptides; Stereoisomerism; Structure-Activity Relationship
PubMed: 16722632
DOI: 10.1021/jm051026+ -
Psychopharmacology Bulletin 1986
Topics: Adjuvants, Immunologic; Adult; Enkephalin, Methionine; Humans; T-Lymphocytes
PubMed: 3492723
DOI: No ID Found -
Anatomy and Embryology Apr 2003The distribution of methionine-enkephalin-Arg6-Gly7-Leu8-immunoreactive cell bodies and fibres was studied in the brainstem of the cat using an indirect immunoperoxidase... (Comparative Study)
Comparative Study
The distribution of methionine-enkephalin-Arg6-Gly7-Leu8-immunoreactive cell bodies and fibres was studied in the brainstem of the cat using an indirect immunoperoxidase technique. In the mesencephalon, immunoreactive cell bodies were observed in the periaqueductal grey, the dorsal raphe nucleus, the central and pericentral nuclei of the inferior colliculus and the pericentral division of the dorsal tegmental nucleus. In the pons, immunoreactive cell bodies were observed in the dorsolateral division of the pontine nucleus; below the central division of the dorsal tegmental nucleus; above the dorsolateral division of the pontine nucleus, and close to the superior cerebellar peduncle. In the medulla oblongata, immunoreactive cell bodies were observed in the laminar spinal trigeminal nucleus and in the lateral tegmental field; the dorsal motor nucleus of the vagus; the prepositus hypoglossal nucleus; the medial nucleus of the solitary tract; the rostral division of the cuneate nucleus, and close to the parvocellular division of the alaminar spinal trigeminal nucleus. The highest (moderate) density of immunoreactive fibres was observed in the periaqueductal grey; the parvocellular and magnocellular divisions of the alaminar spinal trigeminal nucleus; the laminar spinal trigeminal nucleus; the rostral division of the cuneate nucleus; the dorsal motor nucleus of the vagus; the lateral nucleus of the solitary tract, and in the midline between the central divisions of the reticulotegmental pontine nucleus. The widespread distribution of methionine-enkephalin-Arg6-Gly7-Leu8 in the cat brainstem indicates that the peptide might be involved in several physiological functions.
Topics: Animals; Antibody Specificity; Brain Stem; Cats; Enkephalin, Methionine; Fluorescent Antibody Technique, Indirect; Immunoenzyme Techniques; Macaca; Male; Nerve Fibers; Neurons; Rats; Species Specificity
PubMed: 12698364
DOI: 10.1007/s00429-003-0308-7 -
Pediatric Research Feb 1983The cardiovascular and respiratory effects of the naturally occurring endogenous opiate, methionine-enkephalin, were studied in 23 fetal sheep, five newborn lambs, 15... (Comparative Study)
Comparative Study
The cardiovascular and respiratory effects of the naturally occurring endogenous opiate, methionine-enkephalin, were studied in 23 fetal sheep, five newborn lambs, 15 pregnant sheep, and four nonpregnant ewes. The opiate peptide produced dose-dependent decreases in heart rate and blood pressure in fetal and neonatal lambs but increased heart rate and blood pressure followed immediately by decreased heart rate and blood pressure in pregnant ewes. The circulatory responses were examined by pharmacologic blockade of receptor activity and by vagotomy. The bradycardia and hypotension in the fetus and tachycardia and hypertension in the adult were shown to be mediated by autonomic efferent nerves. Sinoaortic denervation did not affect the fetal responses to infused enkephalin. Respiration decreased in fetal as well as postnatal animals even at doses of methionine-enkephalin that did not significantly affect heart rate and blood pressure. These data indicate that the cardiovascular effects of infused enkephalins undergo maturational changes and are mediated by the autonomic nervous system.
Topics: Aging; Animals; Animals, Newborn; Blood Pressure; Bradycardia; Dose-Response Relationship, Drug; Enkephalin, Methionine; Female; Fetus; Heart Rate; Hypertension; Hypotension; Pregnancy; Sheep; Tachycardia; Time Factors
PubMed: 6828334
DOI: 10.1203/00006450-198302000-00016 -
The Journal of Biological Chemistry Feb 1983The biosynthesis and initial processing of the methionine-enkephalin precursor preproenkephalin A were examined by cell-free translation of mRNA from brain and adrenal...
The biosynthesis and initial processing of the methionine-enkephalin precursor preproenkephalin A were examined by cell-free translation of mRNA from brain and adrenal medulla. A novel antiserum raised against Met-enkephalin-Arg6-Phe7 was shown to react with bovine adrenal medulla fractions (apparent Mr 34,000) containing proenkephalin A. Affinity-purified antibodies from this antiserum were used to immunoprecipitate cell-free translated [35S]Met-enkephalin-containing protein. A protein of apparent Mr 30,000 +/- 500 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was the only Met-enkephalin precursor consistently synthesized by translation of mRNA from bovine or guinea pig striatum, rat brain, or bovine adrenal medulla. The presence of [35S]Met-enkephalin sequences in this protein was confirmed by high pressure liquid chromatography of trypsin/carboxypeptidase B digests. Dog pancreas endoplasmic reticulum membranes converted the Mr 30,000 protein to an immunoreactive protein of apparent Mr 28,500 that lacked significant core glycosylation. These results suggest that 1) a protein similar or identical to bovine adrenal medullary preproenkephalin A is the major Met-enkephalin precursor synthesized in brain as well as adrenal medulla, and 2) preproenkephalin A is converted to a protein resembling proenkephalin A, presumably by removal of a signal peptide.
Topics: Animals; Antibody Specificity; Brain Chemistry; Chromatography, High Pressure Liquid; Dogs; Enkephalin, Methionine; Guinea Pigs; Immune Sera; Molecular Weight; Protein Biosynthesis; Protein Precursors; Rabbits
PubMed: 6822579
DOI: No ID Found -
Pharmaceutical Research Jul 1991Methionine enkephalin (Met-E) is a naturally occurring pentapeptide. It appears to mediate pain perception by blocking CNS pathways. Using rabbits, a log dose...
Methionine enkephalin (Met-E) is a naturally occurring pentapeptide. It appears to mediate pain perception by blocking CNS pathways. Using rabbits, a log dose relationship was obtained between Met-E-induced dilation of the pupil (mydriasis) and constant intravenous infusion dose rates (14, 20, 28, 37, 56, 73, and 129 micrograms/min/kg). Steady-state dilation is reached within 9 min. Dose-effect curves (DEC) were fitted by a linear regression analysis of the log dose versus percentage dilation plots. Fitted DEC were used to determine temporal profiles for the relative biophasic drug level.
Topics: Animals; Dose-Response Relationship, Drug; Enkephalin, Methionine; Infusions, Intravenous; Pupil; Rabbits; Regression Analysis
PubMed: 1924146
DOI: 10.1023/a:1015872016718 -
Brain Research Jul 1984The present paper extends and refines previous observations of enkephalin-like immunoreactivity in the guinea-pig cochlea. Firstly, Met-enkephalin was identified and a...
The present paper extends and refines previous observations of enkephalin-like immunoreactivity in the guinea-pig cochlea. Firstly, Met-enkephalin was identified and a quantitative evaluation was made by combining high-performance liquid chromatography (HPLC) and a specific radioimmunoassay. Both the antibody specificity and the HPLC purification allowed us to demonstrate the co-existence, in the cochlea, of at least 3 opioid peptides: Met-enkephalin, Leu-enkephalin and Met-enkephalin-Arg6-Phe7. Secondly, a pre-embedding immunoperoxidase technique was used on whole or dissected cochleas. Immunoreactivity was localized in efferent fibers (coming from the brainstem) in the inner spiral bundle, tunnel spiral bundle and intraganglionic spiral bundle. In the inner spiral bundle vesiculated Met-enkephalin-immunoreactive fibers could be seen synapsing with afferent auditory dendrites. It is hypothesized that these Met-enkephalin immunoreactive fibers (belonging to the lateral efferent system) could be responsible for an inhibitory effect upon the gross cochlear action potential.
Topics: Animals; Chromatography, High Pressure Liquid; Cochlea; Enkephalin, Methionine; Guinea Pigs; Immunoenzyme Techniques; Microscopy, Electron; Radioimmunoassay
PubMed: 6378324
DOI: 10.1016/0006-8993(84)90437-2 -
Neuroscience Letters Jun 1985Lumbar paravertebral ganglia and prevertebral ganglia of the rat were immunohistochemically examined using an antiserum against Methionine-enkephalin-Arg6-Gly7-Leu8...
Methionine-enkephalin-Arg6-Gly7-Leu8-immunoreactive nerve fibers and cell bodies in lumbar paravertebral ganglia and the celiac-superior mesenteric ganglion complex of the rat: an immunohistochemical study.
Lumbar paravertebral ganglia and prevertebral ganglia of the rat were immunohistochemically examined using an antiserum against Methionine-enkephalin-Arg6-Gly7-Leu8 (Met-Enk-Arg-Gly-Leu). Colchicine (5 mg/kg body wt., i.p. injection) was employed as an axonal transport blocker to intensify the immunoreactivity in the nerve cell bodies. In the lumbar paravertebral ganglia of the colchicine-treated rats, about 55% of nerve cell bodies showed a positive immunoreactivity. In the celiac-superior mesenteric ganglion complex, a dense network of positively immunostained nerve fiber varicosities surrounded immunonegative nerve cell bodies. The Met-Enk-Arg-Gly-Leu-like immunoreactivity demonstrated in this study suggests the occurrence of preproenkephalin A and related opioid peptides.
Topics: Animals; Colchicine; Enkephalin, Methionine; Ganglia, Sympathetic; Immunoenzyme Techniques; Male; Rats; Rats, Inbred Strains
PubMed: 3897912
DOI: 10.1016/0304-3940(85)90058-8 -
Journal of Immunological Methods Jul 1990An enzyme-linked immunosorbent assay (ELISA) for the sulphoxide derivative of the opioid peptide methionine enkephalin (MOE) was developed and found to be sensitive and... (Comparative Study)
Comparative Study
An enzyme-linked immunosorbent assay (ELISA) for the sulphoxide derivative of the opioid peptide methionine enkephalin (MOE) was developed and found to be sensitive and highly specific. Methionine enkephalin itself showed only low cross-reactivity (1.8%) in the assay while leucine enkephalin and the endorphins showed cross-reactivity no higher than 0.6%. Given the ease of application, low cost and stable nature of the label, this technique is a useful alternative to existing radioimmunoassays for the peptide.
Topics: Animals; Antibody Specificity; Cross Reactions; Enkephalin, Methionine; Enzyme-Linked Immunosorbent Assay; Radioimmunoassay; Rats; Rats, Inbred Strains
PubMed: 2380569
DOI: 10.1016/0022-1759(90)90233-l