Table 2

Potency ratios for the 18 groups of rats in the tolerance and cross-tolerance experiments

Test Agonist	Potency Ratio	(95% CL)	Potency Ratio	(95% CL)
	0.003 Etorphine Alone		0.003 Etorphine ⁺ 3.0 LY235959
Etorphine	1.0	(0.8–1.3)	0.9	(0.5–1.8)
Morphine	2.2	(1.5–3.1)	1.2	(0.9–1.6)
Dezocine	3.4	(1.9–6.2)	1.2	(0.5–2.9)

	10.0 Morphine Alone		10.0 Morphine ⁺ 3.0 LY235959
Etorphine	2.5	(1.9–3.4)	1.4	(1.1–2.0)
Morphine	2.9	(2.0–4.4)	1.2	(0.9–1.6)
Dezocine	—^2-a	—	4.0	(1.8–9.5)

	3.0 Dezocine Alone		3.0 Dezocine ⁺ 3.0 LY235959
Etorphine	4.1^2-b	(2.8–6.1)	2.4	(1.4–3.7)
Morphine	3.5	(2.5–5.0)	1.7	(1.1–2.6)
Dezocine	9.6^2-b	(4.9–18.9)	2.8	(1.5–5.5)

Labels to the left of the columns represent the test drug for a group (Test Agonist). Labels in the columns represent the chronic treatment condition. Values in parentheses represent the 95% confidence limits (CL) for each potency ratio.

↵2-a —, values could not be determined.
↵2-b Slopes are significantly different at P < .05.