scholarly journals Opioid receptors in GtoPdb v.2021.3

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Anna Borsodi ◽  
Michael Bruchas ◽  
Girolamo Caló ◽  
Charles Chavkin ◽  
MacDonald J. Christie ◽  
...  
Keyword(s):  
Opioid Receptors ◽  
Opioid Analgesics ◽  
Structural Homology ◽  
Orphanin Fq ◽  
Dynorphin A ◽  
Greek Letter ◽  
Endogenous Peptides ◽  
High Degree ◽  
Μ Receptor

Opioid and opioid-like receptors are activated by a variety of endogenous peptides including [Met]enkephalin (met), [Leu]enkephalin (leu), β-endorphin (β-end), α-neodynorphin, dynorphin A (dynA), dynorphin B (dynB), big dynorphin (Big dyn), nociceptin/orphanin FQ (N/OFQ); endomorphin-1 and endomorphin-2 are also potential endogenous peptides. The Greek letter nomenclature for the opioid receptors, μ, δ and κ, is well established, and NC-IUPHAR considers this nomenclature appropriate, along with the symbols spelled out (mu, delta, and kappa), and the acronyms, MOP, DOP, and KOP. [121, 100, 91]. The human N/OFQ receptor, NOP, is considered 'opioid-related' rather than opioid because, while it exhibits a high degree of structural homology with the conventional opioid receptors [294], it displays a distinct pharmacology. Currently there are numerous clinically used drugs, such as morphine and many other opioid analgesics, as well as antagonists such as naloxone, however only for the μ receptor.

scholarly journals Opioid receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

2019 ◽  
Vol 2019 (4) ◽  
Author(s):  
Anna Borsodi ◽  
Michael Bruchas ◽  
Girolamo Caló ◽  
Charles Chavkin ◽  
MacDonald J. Christie ◽  
...  
Keyword(s):  
Opioid Receptors ◽  
Opioid Analgesics ◽  
Structural Homology ◽  
Orphanin Fq ◽  
Dynorphin A ◽  
Greek Letter ◽  
Endogenous Peptides ◽  
High Degree ◽  
Μ Receptor

Opioid and opioid-like receptors are activated by a variety of endogenous peptides including [Met]enkephalin (met), [Leu]enkephalin (leu), β-endorphin (β-end), α-neodynorphin, dynorphin A (dynA), dynorphin B (dynB), big dynorphin (Big dyn), nociceptin/orphanin FQ (N/OFQ); endomorphin-1 and endomorphin-2 are also potential endogenous peptides. The Greek letter nomenclature for the opioid receptors, μ, δ and κ, is well established, and NC-IUPHAR considers this nomenclature appropriate, along with the symbols spelled out (mu, delta, and kappa), and the acronyms, MOP, DOP, and KOP. [116, 96, 88]. The human N/OFQ receptor, NOP, is considered 'opioid-related' rather than opioid because, while it exhibits a high degree of structural homology with the conventional opioid receptors [282], it displays a distinct pharmacology. Currently there are numerous clinically used drugs, such as morphine and many other opioid analgesics, as well as antagonists such as naloxone, however only for the μ receptor.

Pretreatment of rats with the irreversible μ-receptor antagonist, β-FNA, fails to prevent naltrexone-induced upregulation of μ-opioid receptors

1990 ◽  
Vol 29 (9) ◽  
pp. 805-810 ◽  
Author(s):  
R.B. Rothman ◽  
J.B. Long ◽  
V. Bykov ◽  
A.E. Jacobson ◽  
K.C. Rice ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Opioid Receptors ◽  
Μ Opioid Receptors ◽  
Μ Receptor

Brain dynein crossbridges microtubules into bundles

1989 ◽  
Vol 93 (1) ◽  
pp. 19-28 ◽  
Author(s):  
L.A. Amos
Keyword(s):  
Cytoplasmic Dynein ◽  
Molecular Forms ◽  
Mammalian Brain ◽  
Structural Homology ◽  
Greek Letter ◽  
Major Band ◽  
Negative Stain ◽  
Globular Particle ◽  
Axonemal Dynein ◽  
Individual Particles

Cytoplasmic dynein was purified from pig brain, using a modified version of published procedures, in order to study its interaction with microtubules. Since the preparation produces ATP-dependent sliding of taxol-stabilized purified microtubules over glass and runs on SDS-containing gels as a major band exceeding 300,000 Mr plus a medium chain band at about 75,000 Mr, it is assumed to be identical to the mammalian brain dynein (MAP 1C) purified by Vallee and colleagues. When viewed by electron microscopy in negative stain, individual particles show two distinct configurations. Some are clearly similar to the two-headed bouquet structure already shown for MAP 1C. A larger number of molecules in the present preparation appear to have two heads fused together, forming a dimeric globular particle with two separate tails. They are referred to as phiparticles, because of their resemblance to the greek letter phi. A model for the structural relationship between the two molecular forms is presented. The stems of two associated dynein subunits may separate beyond the base, to form a bouquet, or they may remain fused to form the larger tail of a phi-particle. The smaller tail probably represents a combined pair of features equivalent to the ‘stalks’ shown to emanate from axonemal dynein heads by Goodenough and colleagues. Both tails of a phi-particle can bind to microtubules, even in the presence of ATP, and cause microtubule bundling. These results suggest a complete structural homology between axonemal and cytoplasmic dynein.

scholarly journals Evidence that Orphanin FQ Mediates Progesterone Negative Feedback in the Ewe

Endocrinology ◽  
2013 ◽  
Vol 154 (11) ◽  
pp. 4249-4258 ◽  
Author(s):  
Casey C Nestor ◽  
Lique M. Coolen ◽  
Gail L. Nesselrod ◽  
Miro Valent ◽  
John M. Connors ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Negative Feedback ◽  
Luteal Phase ◽  
Arcuate Nucleus ◽  
Pulse Amplitude ◽  
Estrogen Receptor Α ◽  
Pulse Frequency ◽  
Orphanin Fq ◽  
High Degree ◽  
Lh Secretion

Orphanin FQ (OFQ), a member of the opioid family, is found in many areas of the hypothalamus and, when given centrally OFQ inhibits episodic LH secretion in rodents and sheep. Because GnRH neurons are devoid of the appropriate receptors to mediate steroid negative feedback directly, neurons that release OFQ may be involved. Using immunocytochemistry, we first determined that most OFQ neurons in the arcuate nucleus (ARC) and other hypothalamic regions of luteal phase ewes contained both estrogen receptor α and progesterone (P) receptor. Given a similar high degree of steroid receptor colocalization in other ARC subpopulations, we examined whether OFQ neurons of the ARC contained those other neuropeptides and neurotransmitters. OFQ did not colocalize with kisspeptin, tyrosine hydroxylase, or agouti-related peptide, but all ARC OFQ neurons coexpressed proopiomelanocortin. To test for a role for endogenous OFQ, we examined the effects of an OFQ receptor antagonist, [Nphe1,Arg14,Lys15]Nociceptin-NH2 (UFP-101) (30 nmol intracerebroventricular/h), on LH secretion in steroid-treated ewes in the breeding season and ovary-intact ewes in anestrus. Ovariectomized ewes with luteal phase concentrations of P and estradiol showed a significant increase in LH pulse frequency during infusion of UFP-101 (4.5 ± 0.5 pulses/6 h) compared with saline infusion (2.6 ± 0.4 pulses/6 h), whereas ewes implanted with only estradiol did not. Ovary-intact anestrous ewes displayed no significant differences in LH pulse amplitude or frequency during infusion of UFP-101. Therefore, we conclude that OFQ mediates, at least in part, the negative feedback action of P on GnRH/LH pulse frequency in sheep.

Orphanin FQ, but not dynorphin A, accelerates colonic transit in rats

2000 ◽  
Vol 119 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Toku Takahashi ◽  
Yohei Mizuta ◽  
Chung Owyang
Keyword(s):  
Colonic Transit ◽  
Orphanin Fq ◽  
Dynorphin A

Dynorphin A(1-8): stability and implications for in vitro opioid activity

1998 ◽  
Vol 76 (3) ◽  
pp. 325-333 ◽  
Author(s):  
K M Bell ◽  
J R Traynor
Keyword(s):  
Guinea Pig ◽  
Opioid Receptors ◽  
Vas Deferens ◽  
C6 Glioma Cells ◽  
Guinea Pig Ileum ◽  
Dynorphin A ◽  
Mouse Vas Deferens ◽  
Peptidase Inhibitors ◽  
Delta Receptors

The opioid binding profile and in vitro activity of the endogenous opioid peptide dynorphin A(1-8) have been studied. At opioid receptors in guinea-pig brain dynorphin A(1-8) was nonselective, although with some preference for the delta receptor (Ki 4.6 nM) over µ (Ki 18 nM) and kappa (Ki 40 nM) receptors. However, a high degree of metabolism was observed, with less than 10% of added dynorphin A(1-8) remaining at the end of the binding assay. In the presence of peptidase inhibitors to prevent breakdown of the N- and C-termini and the Gly3-Phe4 bond the major metabolite was [Leu5]enkephalin (representing 49% recovered material). This was reduced by inclusion of an inhibitor of endopeptidase EC 3.4.24.15. In the presence of all the peptidase inhibitors the affinity for kappa receptors (Ki 0.5 nM) relative to µ and delta receptors increased, but no selectivity of binding was observed. This lack of selectivity was confirmed using membranes from C6 glioma cells expressing rat opioid receptors. The agonist effect of dynorphin A(1-8) in the mouse vas deferens (EC50 116 nM) and guinea-pig ileum (EC50 38 nM) was mediated through the kappa receptor as evidenced by the rightward shifts afforded by the kappa -selective antagonist norbinaltorphimine. In the presence of peptidase inhibition potency was improved 2-fold in the mouse vas deferens and 20-fold in the guinea-pig ileum, but this agonist activity was mediated through delta receptors in the vas deferens and µ receptors in the ileum, as a result of the formation and stabilization of [Leu5]enkephalin. The results confirm the absence of receptor selectivity of dynorphin A(1-8) in binding assays but show that its agonist effects, at least in vitro, are mediated exclusively through the kappa opioid receptor.Key words: dynorphin A(1-8), opioid receptors, peptide metabolism, mouse vas deferens, guinea-pig ileum.

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