Figure 2: Effect of EA and a systemic injection of ketanserin on weight bearing in rats with osteoarthritis. EA significantly decreased weight-bearing differences compared to sham EA on days 3–7 after iodoacetate. Ketanserin pretreatment blocked the analgesic effect of EA but did not influence weight bearing in sham EA control rats. * , ** , *** versus sham + vehicle; # , & versus EA + ketanserin.