Figure 2.

Chronic SNC80 and ARM390 both produce analgesic tolerance. Development of tolerance in two mouse strains and two pain models. All animals were tested every 24 h with vehicle (control), SNC80 (10 mg/kg), or ARM390 (10 mg/kg) for 5 d. Left, CFA tail, thermal responses in DOR-eGFP mice. Middle, CFA tail, thermal responses in wild-type C57BL/6J mice. Right, CFA paw, mechanical responses in wild-type C57BL/6J mice. Dashed lines represent baseline mechanical or thermal responses pre-CFA. n = 5–10 mice/group. Analgesic tolerance developed similarly for SNC80 and ARM390, independent of mouse strain or nociceptive endpoint.