Several studies suggested that the amide-type local anesthetic mepivacaine has a longer duration of local anesthetic effect than the same amide-type lidocaine, and has a vasoconstrictor action. However, the mechanism of action on α₂ and α₁ adrenoceptors involved in peripheral vasoconstriction remains unclear.
0.25% mepivacaine with various ligands such as α adorenoceptors antagonists is randomly and blindly injected intracutaneously at a dose of 0.1mL into the back of shaved Hartly male guinea pigs (weight 300-350g). After marking the area around the wheal and confirming that there is a normal skin contraction reaction outside the wheal, six pricks were aplied inside each wheal. The test of six pinpricks was applied at intervals of about 3 to 5 seconds every 5 minutes. The number of times that did not respond to stimulus was measured and the sum (maximum value:132) served as an anesthetic score which indicates the degree of local anesthesia. 
Mepivacaine dose-dependently prolonged the duration of anesthesia and increased local anesthesia scores. Therefore, 0.25% mepivacaine was used and compared with 0.25% lidocaine and 0.25% xylocaine. The anesthetic duration of 0.25% mepivacaine was longer than that of lidocaine and shorter than that of xylocaine.
0.25% mepivacaine were combined with 1 μM yohimbine, 1 μM prazosin, 1 μM JP1302, 10 μM BRL44408, 1 μM SR49059 (selective V_1A receptor blocker V:vasopressin), 10 μM indoramin, 0.5 μM BMY7378, 5 μM cyclazosin, 1 nM silodosin respectively. After mixing, the effect of various antagosits on mepivacaine were examined. As a result, antagonists other than 10 μM BRL44408 and 1 nM silodosin decreased the duration of mepivacaine anesthesia. These results indicated that mepivacaine's peripheral vasoconstrictor activity is mediated at least by α_2C, α_1B, α_1D and V_1Areceptors.