Half-maximal analgesic doses (AD50s) and potency ratios for morphine (5, 7.5, 10, and 15)* and M6G (5, 10, and 15 mg/kg)† inhibition of 49°C tail withdrawal nociception in e/e mutant mice and their wildtype counterparts, C57BL/6
| Drug | Strain | Sex | AD50, mg/kg‡ | Potency ratio, sex§ | Potency ratio, genotype¶ |
|---|---|---|---|---|---|
| *Based on % analgesia scores over a 60 min testing period; three way ANOVA revealed significant main effects of genotype (F1,195 = 13.3, p<0.001) and dose (F4,195 = 37.1, p<0.001) only. | |||||
| †Based on % analgesia scores over a 300 min testing period; three way ANOVA revealed significant main effects of genotype (F1,101 = 20.9, p<0.001) and dose (F2,195 = 37.9, p<0.001) only. AD50s calculated on data from the first 60 min (not shown) revealed M6G to be approximately twice as potent as morphine in all groups in this assay. | |||||
| ‡AD50s calculated using the method of Tallarida and Murray7; values in parentheses are 95% confidence intervals. | |||||
| §The ratio of male AD50:female AD50; values in parentheses are 95% confidence intervals. | |||||
| ¶The ratio of C57BL6 AD50:e/e AD50; values in parentheses are 95% confidence intervals. | |||||
| **Significantly different from 1.0, p<0.05. | |||||
| F, female; M, male. | |||||
| Morphine | C57BL/6 | M+F | 11.3 (10.2 to 12.6) | ||
| M only | 10.7 (8.9 to 12.5) | ||||
| F only | 11.9 (10.4 to 13.6) | 0.9 (0.7 to 1.1) | |||
| e/e | M+F | 8.5 (7.8 to 9.3) | 1.3 (1.2 to 1.5)** | ||
| M only | 8.3 (7.2 to 9.6) | 1.3 (1.0 to 1.6)** | |||
| F only | 8.7 (7.7 to 9.8) | 1.0 (0.8 to 1.2) | 1.4 (1.2 to 1.6)** | ||
| M6G | C57BL/6 | M+F | 13.3 (11.4 to 15.5) | ||
| M only | 17.8 (13.1 to 24.3) | ||||
| F only | 11.9 (9.7 to 14.4) | 1.5 (1.0 to 2.2)* | |||
| e/e | M+F | 8.0 (7.1 to 9.0) | 1.7 (1.4 to 2.0)** | ||
| M only | 9.0 (7.6 to 10.6) | 1.7 (1.3 to 2.4)** | |||
| F only | 6.9 (5.7 to 8.3) | 1.3 (1.0 to 1.7)* | 1.6 (1.3 to 2.2)** | ||