Treatment | Morphine ED50 (95% CI) | |
---|---|---|
Day 1 | Day 4 | |
Sham + morphine (15 + 30) | 2.6 (1.8–3.5) | 6.7 (5.1–8.8)1-a |
LY293558-15 + morphine | 2.3 (1.6–3.2) | 6.1 (4.3–8.3)1-a |
LY293558-30 + morphine | 1.9 (1.3–2.7) | 2.8 (2.0–3.9)1-b |
Sham + morphine (45) | 4.3 (3.4–5.1) | 10.8 (8.9–12.9)1-a |
LY293558-45 + morphine | 4.0 (3.3–4.9) | 5.3 (4.4–6.5)1-b |
Sham + morphine (60) | 4.1 (3.4–5.0) | 11.1 (9.3–13.4)1-a |
Sham + saline | 3.9 (2.9–5.3) | 4.0 (2.7–6.0) |
LY293558-60 + morphine | 2.8 (2.1–3.6) | 5.7 (4.8–6.7)1-b |
LY293558-60 + saline | 2.8 (2.1–3.6) | 2.5 (1.0–4.1) |
ED50 values (mg/kg) for morphine and 95% CI were determined before (day 1) and after (day 4) 3 days of morphine injections, three times per day at 10, 20 and 40 mg/kg on days 1, 2 and 3, respectively. Mice received either LY293558 (15, 30, 45 or 60 mg/kg/24 hr)via an osmotic pump or sham surgery 16 hr before the first dose of morphine dose or saline on day 1. The concurrent controls (sham + morphine) for each dose of LY293558 + morphine are indicated by the numbers given below in parentheses.