1
|
Zhou J, Zhao L, Wei S, Wang Y, Zhang X, Ma M, Wang K, Liu X, Wang R. Contribution of the μ opioid receptor and enkephalin to the antinociceptive actions of endomorphin-1 analogs with unnatural amino acid modifications in the spinal cord. Peptides 2021; 141:170543. [PMID: 33794284 DOI: 10.1016/j.peptides.2021.170543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/08/2021] [Accepted: 03/22/2021] [Indexed: 01/20/2023]
Abstract
Endomorphin analogs containing unnatural amino acids have demonstrated potent analgesic effects in our previous studies. In the present study, the differences in antinociception and the mechanisms thereof for analogs 1-3 administered intracerebroventricularly and intrathecally were explored. All analogs at different routes of administration produced potent analgesia compared to the parent peptide endomorphin-1. Multiple antagonists and antibodies were used to explore the mechanisms of action of these analogs, and it was inferred that analogs 1-3 stimulated the μ opioid receptor to induce antinociception. Moreover, the antibody data suggested that analog 2 may induce the release of immunoreactive [Leu5]-enkephaline and [Met5]-enkephaline to produce a secondary component of antinociception at the spinal level and analog 3 may stimulate the the release of immunoreactive [Met5]-enkephaline at the spinal level. Finally, analogs 2 and 3 produced no acute tolerance in the spinal cord. We hypothesize that the unique characteristics of the endomorphin analogs result from their capacities to stimulate the release of endogenous antinociceptive substances.
Collapse
Affiliation(s)
- Jingjing Zhou
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Long Zhao
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Shuang Wei
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Yuan Wang
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China.
| | - Xianghui Zhang
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Mengtao Ma
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Kairong Wang
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Xin Liu
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China.
| | - Rui Wang
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China.
| |
Collapse
|
2
|
Mizoguchi H, Takagi H, Watanabe C, Yonezawa A, Sato T, Sakurada T, Sakurada S. Involvement of multiple µ-opioid receptor subtypes on the presynaptic or postsynaptic inhibition of spinal pain transmission. Peptides 2014; 51:15-25. [PMID: 24512946 DOI: 10.1016/j.peptides.2013.10.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 10/16/2013] [Accepted: 10/16/2013] [Indexed: 11/17/2022]
Abstract
The involvement of the μ-opioid receptor subtypes on the presynaptic or postsynaptic inhibition of spinal pain transmission was characterized in ddY mice using endomorphins. Intrathecal treatment with capsaicin, N-methyl-d-aspartate (NMDA) or substance P elicited characteristic nociceptive behaviors that consisted primarily of vigorous biting and/or licking with some scratching. Intrathecal co-administration of endogenous μ-opioid peptide endomorphin-1 or endomorphin-2 resulted in a potent antinociceptive effect against the nociceptive behaviors induced by capsaicin, NMDA or substance P, which was eliminated by i.t. co-administration of the μ-opioid receptor antagonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP). The antinociceptive effect of endomorphin-1 was significantly suppressed by i.t.-co-administration of the μ2-opioid receptor antagonist Tyr-D-Pro-Trp-Phe-NH2 (D-Pro2-endomorphin-1) but not the μ1-opioid receptor antagonist Tyr-D-Pro-Phe-Phe-NH2 (D-Pro2-endomorphin-2) on capsaicin- or NMDA-elicited nociceptive behaviors. In contrast, the antinociceptive effect of endomorphin-2 was significantly suppressed by i.t.-co-administration of D-Pro2-endomorphin-2 but not D-Pro2-endomorphin-1 on capsaicin-, NMDA- or substance P-elicited nociceptive behaviors. Interestingly, regarding substance P-elicited nociceptive behaviors, the antinociceptive effect of endomorphin-1 was significantly suppressed by i.t.-co-administration of another μ2-opioid receptor antagonist, Tyr-D-Pro-Trp-Gly-NH2 (D-Pro2-Tyr-W-MIF-1), but not D-Pro2-endomorphin-1 or D-Pro2-endomorphin-2. The present results suggest that the multiple μ-opioid receptor subtypes are involved in the presynaptic or postsynaptic inhibition of spinal pain transmission.
Collapse
|
4
|
Abstract
This paper is the thirtieth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2007 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.
Collapse
Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd.,Flushing, NY 11367, United States.
| |
Collapse
|
5
|
Pan W, Kastin AJ. From MIF-1 to endomorphin: the Tyr-MIF-1 family of peptides. Peptides 2007; 28:2411-34. [PMID: 17988762 DOI: 10.1016/j.peptides.2007.10.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2007] [Revised: 10/10/2007] [Accepted: 10/10/2007] [Indexed: 11/22/2022]
Abstract
The Tyr-MIF-1 family of small peptides has served a prototypic role in the introduction of several novel concepts into the peptide field of research. MIF-1 (Pro-Leu-Gly-NH(2)) was the first hypothalamic peptide shown to act "up" on the brain, not just "down" on the pituitary. In several situations, including clinical depression, MIF-1 exhibits an inverted U-shaped dose-response relationship in which increasing doses can result in decreasing effects. This tripeptide also can antagonize opiate actions, and the first report of such activity also correctly predicted the discovery of other endogenous antiopiate peptides. The tetrapeptide Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH(2)) not only shows antiopiate activity, but also considerable selectivity for the mu-opiate binding site. Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH(2)) is an even more selective ligand for the mu receptor, leading to the discovery of two more Tyr-Pro tetrapeptides that have the highest specificity and affinity for this site. These are the endomorphins: endomorphin-1 is Tyr-Pro-Trp-Phe-NH(2) and endomorphin-2 is Tyr-Pro-Phe-Phe-NH(2). Tyr-MIF-1 proved, contrary to the then prevailing dogma, that peptides can be saturably transported across the blood-brain barrier by a quantifiable transport system. Unexpectedly, the Tyr-MIF-1 transporter is shared with Met-enkephalin. In the era in which it was doubtful whether a peripheral peptide could exert CNS effects, the Tyr-MIF-1 family of peptides also explicitly showed that they can exert more than one central action that persists longer than their half-lives in blood. These peptides clearly illustrate that the name of a peptide restricts neither its actions nor its conceptual implications.
Collapse
Affiliation(s)
- Weihong Pan
- Blood-Brain Barrier Group, Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA.
| | | |
Collapse
|