High impact information on Met-enk-AP

• The incubation of YGGFMRF with synaptic membranes yielded YGGFM and RF as the degradation products [1].
• The relatively large amount of YGGFMRF immunoreactivity, which was detected both biochemically and immunohistochemically, indicates that YGGFMRF-ir peptides may be important proenkephalin A-derived products in the pituitary gland [2].
• It is also possible that some of the cerebral effects of these compounds may be referable to an enhancement of YGGFMRF action in the central nervous system [3].
• These observations indicate that endogenously released YGGFMRF is protected from degradation by Hoe 498 diacid and that systemically administered Hoe 498 diacid or monoester penetrate the blood-brain barrier and inhibit brain and cerebrospinal fluid dipeptidyl carboxypeptidase activity [3].
• In the spinal cord Met5-enkephalin-Arg6-Phe7 (YGGFMRF) is located in small interneurons of the dorsal and ventral horns [4].

Biological context of Met-enk-AP

• Blood pressure elevation in rats by peripheral administration of Tyr-Gly-Gly-Phe-Met-Arg-Phe and the invertebrate neuropeptide, Phe-Met-Arg-Phe-NH2 [5].
• The purified bioactive substances were further subjected to amino acid sequence analysis and were characterized as peptides with the following sequences: Tyr-Gly-Gly-Phe-Met, Tyr-Gly-Gly-Phe-Leu, and Tyr-Gly-Gly-Phe-Met-Arg-Phe [6].

Anatomical context of Met-enk-AP

• Thus, purification by ion exchange chromatography prior to RIA appeared to be the most suitable by providing measurable levels of both MEAP and DYNB in all tissues analyzed (highest in bone marrow, lowest in cortical bone) [7].
• Physiological studies on the isolated blowfly salivary gland show that synthetic YGGFMRF is a potent secretagogue with a maximal rate of fluid secretion induced at a concentration of between 10(-13) and 10(-12) M [8].
• The endogenous opioid heptapeptide (Tyr-Gly-Gly-Phe-Met-Arg-Phe; MERF) has been shown to interact with multiple opioid as well as non-opioid sites in mammalian brain membranes [9].
• The occurrence of methionine-enkephalin-Arg(6)-Phe(7) (MEAP) and dynorphin B (DYNB) representing two main precursors of opioids was analyzed in specimens from rat cortical bone, periosteum, bone marrow and joint tissue by radioimmunoassay (RIA) [7].
• The presence of met5-enkephalin-arg6-phe7 into circulation indicates that it may have some physiological role, however it is unknown whether circulating YGGFMRF originates from adrenal medulla, intermediate lobe of pituitary or some other site [10].

Associations of Met-enk-AP with other chemical compounds

• Substance P (10(-6) M) injected in the fluid perfusing the subarachnoidal spaces of the spinal cord can release met5-enkephalin (YGGFM) and met5-enkephalin-Arg6-Phe7 (YGGFMRF) from spinal cord [11].
• The YGGFMRF content of rabbit plasma increased following inhibition of dipeptidyl peptidase activity by an intravenous injection of captopril [10].
• Five opioid peptides (immunoreactivity) derived from their respective opioid precursors were measured in neuroblastoma-glioma hybrid cells (NG 108CC15; pmol/g protein): heptapeptide (Tyr-Gly-Gly-Phe-Met-Arg-Phe), 13.0 +/- 2.6; alpha-neoendorphin, 6.6 +/- 0.8; dynorphin A, 4.4 +/- 1.5; dynorphin A 1-8, 1.3 +/- 0.29; beta-endorphin, 0.3 +/- 0.13 [12].

Analytical, diagnostic and therapeutic context of Met-enk-AP

• Action of peptidase inhibitors on methionine5-enkephalin-arginine6-phenylalanine7 (YGGFMRF) and methionine5-enkephalin (YGGFM) metabolism and on electroacupuncture antinociception [4].
• Neuropeptides identified with a radioimmunoassay specific for the C-terminus of Met5-enkephalin-Arg6-Phe7 (YGGFMRF) have been extracted from nervous tissues of the blowfly Calliphora vomitoria and also from whole flies [8].
• Regional microdissection revealed the dorsal grey matter to be highest in YGGFMRF content followed by ventral gray, ventral white and dorsal white matter; a similar pattern was observed for Met5-enkephalin [13].
• The distribution of an opioid peptide related to YGGFMRF was determined in the CNS and other organs of the pond snail, Lymnaea stagnalis, by RIA and immunocytochemistry [14].
• The metabolic clearance rate of YGGFMRF is slower than that of met5-enkephalin [10].

References