Fig. 2. Comparative pronociceptive effects of intravenous naloxone (A ) and intraplantar naloxone methiodide (B ) on vocalization thresholds to paw pressure (VTPP) of the inflamed paw after the first (open circles) and a second (solid circles) carrageenan plantar injection performed in the same hind paws 7 days apart. Data (mean ± SD, n = 5) are given as grams.