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Chronic Post-Ischemia Pain Model for Complex Regional Pain Syndrome Type-I in Rats
Published on: January 21, 2020
Effects of imidazoline I2 receptor ligands on acute nociception in rats
Cristal Sampson1, Yanan Zhang, Fabio Del Bello
1Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14214-3000, USA.
Abstract:
This study examined the antinociceptive effects of seven imidazoline I2 receptor ligands in a rat warm water tail withdrawal procedure (46 and 50 °C). Agmatine, 2-BFI, phenyzoline, and diphenyzoline produced a significant antinociceptive activity at 46 °C. BU224, S22687, and idazoxan had no effect at 46 °C up to doses that altered the locomotor activity. None of the drugs showed antinociceptive activity at 50 °C. It is suggested that I2 receptor agonists have antinociceptive activity for acute phasic pain under weak noxious stimulus, and the effects are efficacy-dependent. These data explain the findings that I2 receptor agonists enhance the antinociceptive effects of opioids and support developing higher-efficacy I2 receptor agonists for the treatment of pain.
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