TABLE 1

Brain and blood levels of 6-MAM (% of control) 5 and 25 min after a single heroin or 6-MAM injection (1.25–2.5 μmol/kg, s.c.) in mice pretreated with anti-6-MAM mAb (10–100 mg/kg, i.p.) 48 hours prior to opioid injection. Total drug doses are on the basis of administration to a 25-g mouse (n = 5–14).

	Drug Dose	Total Drug Dose	mAb Dose	Total mAb Binding Sites	Drug/mAb Binding Sites	Brain 6-MAM		Blood 6-MAM
	Drug Dose	Total Drug Dose	mAb Dose	Total mAb Binding Sites	Drug/mAb Binding Sites	5 min	25 min	5 min	25 min
	μmol/kg	nmol	mg/kg	nmol	ratio	% of control	% of control	% of control	% of control
Heroin	2.5	62.5	10	3.3	19	73 ± 13	44 ± 3***	117 ± 22	94 ± 11
	2.5	62.5	50	16.7	4	n.m.	21 ± 2***	n.m.	62 ± 11
	2.5	62.5	100	33.3	2	n.m.	23 ± 3***	n.m.	74 ± 13
	1.25	31.3	100	33.3	1	63 ± 10	n.m.	330 ± 67**	n.m.
6-MAM	2.5	62.5	10	3.3	19	43 ± 12**	32 ± 3***	101 ± 17	71 ± 11*
	2.5	62.5	50	16.7	4	n.m.	12 ± 1***	n.m.	42 ± 18**
	2.5	62.5	100	33.3	2	n.m.	10 ± 2***	n.m.	158 ± 34
	1.25	31.3	100	33.3	1	26 ± 7*	n.m.	307 ± 64*	n.m.

n.m., not measured; Mann-Whitney U test; *P < 0.05, **P < 0.01, ***P < 0.001.