Aim: To investigate experimentally the effects of methionine enkephalin on signal transduction of mouse myeloma NS-1 cells.
Methods: The antigen determinate of delta opioid receptor was designed in this lab and the polypeptide fragment of antigen determinate with 12 amino acids residues was synthesized. Monoclonal antibody against this peptide fragment was prepared. Proliferation of Mouse NS-1 cells treated with methionine enkephalin of 1 x 10(-6) mol x L(-1) was observed. The activities of protein kinase A (PKA) and protein kinase C (PKC) were measured and thereby the mechanism of effect of methionine enkephalin was postulated.
Results: The results demonstrated that methionine enkephalin could enhance the proliferation of NS-1 cells and the effect of methionine enkephalin could be particularly blocked by monoclonal antibody. The activity of PKA was increased in both cytosol and cell membrane. With reference to PKC, the intracellular activity of PKC in NS-1 cells was elevated at 1 x 10(-7) mol x L(-1) and then declined gradually as the concentration of methionine enkephalin was raised. The effects of methionine enkephalin might be reversed by both naloxone and monoclonal antibody.
Conclusion: Coupled with the findings, it indicates that the signal transduction systems via PKA and PKC are involved in the effects of methionine enkephalin by binding with the traditional opioid receptors,and therefore resulting in different biological effects.
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http://dx.doi.org/10.3748/wjg.v9.i1.169 | DOI Listing |
Objective: Aim: The aim of the study was evaluation of the methionine-enkephalin in patients with severe COVID-19 with various activities of the renin-aldosterone system in comparison with COVID-19 patients with pre-existing comorbidities (renal cell cancer, critical limb ischemia) and adverse pregnancy outcomes..
Patients And Methods: Materials and Methods: To test our hypothesis, this case-control study consisted of 20 healthy donors (control group); 49 patients with a positive diagnosis of COVID-19 according to PCR analysis; 15 patients with a positive diagnosis of COVID-19 in combination with renal cell cancer; 29 patients with a positive diagnosis of COVID-19 in combination with critical limb ischemia, 10 pregnant womens with COVID-19.
Mol Pharmacol
October 2024
Departments of Pharmacological Sciences (I.G., A.G., L.A.D.) and Psychiatry (L.A.D.), and Nash Family Department of Neuroscience (L.A.D.), Icahn School of Medicine at Mount Sinai, New York, New York; UCSF Weill Institute for Neurosciences, Department of Neurology, Neuroscience Graduate Program, University of California, San Francisco, California (E.B.M.); and Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York (L.D.F.)
Ketamine is a glutamate receptor antagonist that was developed over 50 years ago as an anesthetic agent. At subanesthetic doses, ketamine and some metabolites are analgesics and fast-acting antidepressants, presumably through targets other than glutamate receptors. We tested ketamine and its metabolites for activity as allosteric modulators of opioid receptors expressed as recombinant receptors in heterologous systems and with native receptors in rodent brain; signaling was examined by measuring GTP binding, -arrestin recruitment, MAPK activation, and neurotransmitter release.
View Article and Find Full Text PDFPhys Chem Chem Phys
August 2024
Department of Nuclear Physics, University of Madras, Chennai, Tamil Nadu, India.
We propose digital nets conformational sampling (DNCS) - an enhanced sampling technique to explore the conformational ensembles of peptides, especially intrinsically disordered peptides (IDPs). The DNCS algorithm relies on generating history-dependent samples of dihedral variables using bitwise XOR operations and binary angle measurements (BAM). The algorithm was initially studied using met-enkephalin, a highly elusive neuropeptide.
View Article and Find Full Text PDFEndogenous opioid neuropeptides serve as important chemical signaling molecules in both the central and peripheral nervous systems, but there are few analytical tools for directly monitoring these molecules . The opioid peptides share the amino acid motif, Tyr-Gly-Gly-Phe-, at the N-terminus. Met-enkephalin is a small opioid peptide comprised of only five amino acids with methionine (Met) incorporated at the C-terminus.
View Article and Find Full Text PDFFree Radic Biol Med
October 2024
National Health Commission Key Laboratory of Cardiovascular Regenerative Medicine, Central China Fuwai Hospital of Zhengzhou University, Fuwai Central China Cardiovascular Hospital & Central China Branch of National Center for Cardiovascular Diseases, Zhengzhou, Henan, 451464, China; Zhengzhou Key Laboratory of Cardiovascular Aging, Fuwai Central China Cardiovascular Hospital, Zhengzhou, Henan, 451464, China; Henan Key Laboratory of Chronic Disease Management, Fuwai Central China Cardiovascular Hospital, Zhengzhou, Henan, 451464, China. Electronic address:
Enkephalins are reportedly correlated with heart function. However, their regulation in the heart remains unexplored. This study revealed a substantial increase in circulating levels of opioid growth factor (OGF) (also known as methionine enkephalin) and myocardial expression levels of both OGF and its receptor (OGFR) in subjects treated with doxorubicin (Dox).
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