G Attarzadeh-Yazdi, E Houshmand and M Jahanshahi
Hormozgan University of Medical Sciences, Iran
Golestan University of Medical Sciences, Iran
Scientific Tracks Abstracts: Anat Physiol
Pain is an issue that millions of people worldwide are suffering from and today lots of money is spent for its treatment. It has been shown that Alpha-2 adrenergic agonists have main role in analgesia. Also, it has been shown that potassium channels play an important role in the analgesic mechanism of alpha-2 adrenergic receptor agonists. The aim of this study was investigating the role of specific potassium channel (large conductance calcium and voltage-activated potassium channels, BK) in analgesia induced by alpha-2 adrenergic receptor agonists. For this purpose, in the present study, 56 male Wistar rats weighing 250-300 g were selected and divided into 7 groups. The groups are, 1: Intraperitoneal injection (IP) of Normal Salin 1 ml/kg; 2: IP injection of Clonidine 0.7 mg/kg; 3: IP injection of Yohimbine 1 mg/kg; 4: IP injection of Yohimbine 1 mg/kg then Clonidine (IP with dose 0.7 mg/kg); 5: Intracranial (ICV) of Yohimbine 5 �¼g/kg; 6: ICV injection of Yohimbine 1 mg/kg then Clonidine 0.7 mg/kg; 7: ICV injection of Iberiotoxin 100 nm then Clonidine (IP with dose 0.7 mg/kg). Saline and DMSO was used as solvent. Chronic pain was checked by using formalin test (Subsutaneous, SC, injection of formalin with dose of 2%). Our results showed that IP injection clonidine reduced chronic pain. The results also showed that injection of IP and ICV of Yohimbine as Alpha-2 adrerenrgic antagonist can block the analgeisa induced by clonidine (p<0.001). Then, it showed that Alpha-2 adrenergic has main role in pain induced by clonidine. Iberiotoxin, as BK channel Blocker, showed analgesia affects on chronic pain and it can affected by clonidine (p<0.001). The results showed that Alpha-2 adrenergic receptor agonist causes analgesia in animals and this effect can be reversed by using Alpha-2 adrenergic receptors antagonists (Yohimbine). Results showed that Alpha-2 Adrenergic receptors have specific role in analgesia. To find out the molecular mechanism of Alpha-2 Adrenergic receptors our data, with using BK potassium channels, revealed that the Bk channels are one of the mechanism of Alpha-2 adrenergic receptors for inducing pain.
G Attarzadeh-Yazdi is a PhD student and Researcher in Physiology department, Hormozgan University of Medical Science, Iran.
Email: gattarzadeh@yahoo.com
