Assessing local anesthetic effect using the mouse tail flick test.
We used the tail flick test to quantify duration of local anesthetic-induced conduction block in the mouse. Using a baseline tail flick latency (TFL) between 1.0 and 2.5 sec, sensory block was considered present if TFL was > or = 4 sec. Two 20-microL local anesthetic injections were made on opposite sides of the tail base. TFL was tested every 10 min, and local block duration was interpreted as the time to return of TFL to < 4 sec. We tested three different concentrations of procaine (1%, 2%, and 4%), tetracaine (0.125%, 0.5%, and 1%), and lidocaine (0.5%, 1%, and 2%) with and without epinephrine. The testing method could discriminate between the duration of the various local anesthetic concentrations used. For the 1% concentrations, the duration of sensory block was 2 +/- 4 min (S.D.) for procaine, 20 +/- 10 min for lidocaine, 40 +/- 10 min for tetracaine, and 66 +/- 15 min for lidocaine with epinephrine. We found this to be a simple and reliable means of assessing local anesthetic conduction block in the mouse.
Department of Anesthesiology, New York University Medical Center, New York 10016.
G J
GJ
Grant
M I
MI
Zakowski
K
K
Vermeulen
L
L
Langerman
S
S
Ramanathan
H
H
Turndorf
D000772:Anesthesia, Local; D000779:Anesthetics, Local; D000818:Animals; D001340:Autonomic Nerve Block; D008297:Male; D051379:Mice; D010147:Pain Measurement / Q000187:drug effects*
D000779:Anesthetics, Local