Individual differences in the sensitivity of cold allodynia to phentolamine in neuropathic rats.
In neuropathic rats sensitive to phentolamine (alpha-adrenoreceptor antagonist, 2 mg/kg, i.p.), prazosin (alpha1-adrenoreceptor antagonist, 0.5 mg/kg, i.p.) significantly attenuated cold allodynia whereas yohimbine (alpha2-adrenoreceptor antagonist, 0.5 mg/kg, i.p.) had no significant effect. In neuropathic rats insensitive to phentolamine, yohimbine significantly exacerbated cold allodynia whereas prazosin had no significant effect. These results suggest that the individual differences in the sensitivity of cold allodynia to phentolamine may be due to the difference in the alpha-adrenoreceptor subtype predominantly involved in cold allodynia.
Kim
Sun Kwang
SK
Department of East-West Medicine, Graduate School, Kyung-Hee University, Seoul, South Korea.
Min
Byung-Il
BI
Kim
Ji Hoon
JH
Hwang
Byung Gil
BG
Yoo
Gi Yong
GY
Park
Dong Suk
DS
Na
Heung Sik
HS
D058668:Adrenergic alpha-1 Receptor Antagonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003080:Cold Temperature; D004195:Disease Models, Animal; D006930:Hyperalgesia / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D009619:Nociceptors / Q000187:drug effects; D010146:Pain / Q000503:physiopathology / Q000517:prevention & control*; D017288:Pain Threshold / Q000187:drug effects; D010523:Peripheral Nervous System Diseases / Q000188:drug therapy / Q000503:physiopathology*; D010646:Phentolamine / Q000008:administration & dosage / Q000494:pharmacology*; D011224:Prazosin / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013127:Spinal Nerves / Q000601:surgery*; D013997:Time Factors; D015016:Yohimbine / Q000008:administration & dosage / Q000494:pharmacology
D058668:Adrenergic alpha-1 Receptor Antagonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists; D015016:Yohimbine; D011224:Prazosin; D010646:Phentolamine