Comparison of nerve conduction blocks by an opioid and a local anesthetic.
The experiments were done on frog sciatic nerves, using a sucrose-gap recording technique. The aim of our study was to investigate and to compare the tonic and phasic conduction blocking potency of tramadol and lidocaine on whole nerve and their interactions with Ca(2+). The concentration of a tramadol solution producing the same amount of tonic and phasic conduction blocks was three and six times higher than that needed for lidocaine, respectively. Increasing the Ca(2+) concentration in the test solution enhanced the conduction blocking potency of tramadol, but decreased that of lidocaine. It is concluded that tramadol blocks nerve conduction like a local anesthetic but with a weaker effect than that of lidocaine. Interactions of Ca(2+) and these drugs suggested that these drugs might have either different binding sites or different action mechanisms.
Mert
Tufan
T
Department of Biophysics, School of Medicine, University of Cukurova, 01330 Balcali, Adana, Turkey.
Gunes
Yasemin
Y
Guven
Mustafa
M
Gunay
Ismail
I
Ozcengiz
Dilek
D
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D008012:Lidocaine / Q000494:pharmacology; D009431:Neural Conduction / Q000187:drug effects*; D011898:Ranidae; D012584:Sciatic Nerve / Q000187:drug effects / Q000502:physiology; D014147:Tramadol / Q000494:pharmacology
D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D014147:Tramadol; D008012:Lidocaine; D002118:Calcium