Activation of I2‐imidazoline receptors enhances supraspinal morphine analgesia in mice: a model to detect agonist and antagonist activities at these receptors

@article{SnchezBlzquez2000ActivationOI,
  title={Activation of I2‐imidazoline receptors enhances supraspinal morphine analgesia in mice: a model to detect agonist and antagonist activities at these receptors},
  author={Pilar S{\'a}nchez-Bl{\'a}zquez and M A Boronat and Gabriel Olmos and Jes{\'u}s A Garc{\'i}a-Sevilla and Javier Garz{\'o}n},
  journal={British Journal of Pharmacology},
  year={2000},
  volume={130}
}
This work investigates the receptor acted upon by imidazoline compounds in the modulation of morphine analgesia. The effects of highly selective imidazoline ligands on the supraspinal antinociception induced by morphine in mice were determined. Intracerebroventricular (i.c.v.) or subcutaneous (s.c.) administration of ligands selective for the I2‐imidazoline receptor, 2‐BFI, LSL 60101, LSL 61122 and aganodine, and the non selective ligand agmatine, increased morphine antinociception in a dose… Expand
Attenuation of acute and chronic effects of morphine by the imidazoline receptor ligand 2‐(2‐benzofuranyl)‐2‐imidazoline in rat locus coeruleus neurons
TLDR
It is demonstrated that 2‐(2‐benzofuranyl)‐2‐imidazoline (2‐BFI) interacts with the opioid system in the rat locus coeruleus and this interaction leads to an attenuation of both the hyperactivity of locus coercionuleus neurons during opiate withdrawal and the development of tolerance to morphine when 2‐B FI is chronically administered. Expand
Tramadol antinociception is potentiated by clonidine through α₂-adrenergic and I₂-imidazoline but not by endothelin ET(A) receptors in mice.
TLDR
Results demonstrate the involvement of opioid but not α₂-adrenergic/I�1-imidazoline receptors in tramadol antinociception and that opioid, α⁂- adrenergic and I₁-imidsized receptors are involved in clonidine potentiation of tramadl antinOCiception. Expand
Antinociceptive Interactions between the Imidazoline I2 Receptor Agonist 2-BFI and Opioids in Rats: Role of Efficacy at the μ-Opioid Receptor
TLDR
It is indicated that lower-efficacy μ-opioid receptor agonists may interact more favorably with I2R ligands than high-efficACY μ-OPioid receptors agonists. Expand
Morphine-induced antinociception in the rat: supra-additive interactions with imidazoline I₂ receptor ligands.
TLDR
Examination of the antinociceptive effects of two selective I(2) receptor ligands 2-BFI and BU224 in a hypertonic saline-induced writhing test and their interaction with morphine using a dose-addition analysis indicates that drugs acting on imidazoline I( 2) receptors may be useful either alone or in combination with opioids for the treatment of pain. Expand
Potentiation of oxycodone antinociception in mice by agmatine and BMS182874 via an imidazoline I2 receptor-mediated mechanism
TLDR
This is the first report demonstrating that BMS182874- or agmatine-induced enhancement of oxycodone antinociception is blocked by BU224 but not by efaroxan. Expand
Identification of the Central Imidazoline Receptor Subtype Involved in Modulation of Halothane-Epinephrine Arrhythmias in Rats
TLDR
It is concluded that central I1, but not I2, receptors play an important role in inhibition of halothane-epinephrine arrhythmia. Expand
Antinociceptive effects of imidazoline I2 receptor agonists in the formalin test in rats
TLDR
The differential antinociceptive effects of I2 receptor agonists and the differential antagonism profiles by idazoxan are revealed, suggesting the involvement of different I2ceptor subtypes in reducing different phases of formalin-induced pain-like behaviors. Expand
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TLDR
Data reveal that phenyzoline is superior to the prototypic I2 receptor ligand 2-BFI for the management of pain and warrants further consideration as a novel analgesic. Expand
Effects of imidazoline I₂ receptor ligands on morphine- and tramadol-induced antinociception in rats.
TLDR
It is suggested that BU224 has lower efficacy than 2-BFI at I₂ receptors, and that the enhancement of opioid antinociception by I ₂ receptor ligands depends on their efficacies. Expand
Effects of imidazoline I2 receptor ligands on acute nociception in rats
TLDR
It is suggested that I2 receptor agonists have antinociceptive activity for acute phasic pain under weak noxious stimulus, and the effects are efficacy-dependent. Expand
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