Table 6

The comparison of antagonism of NTI and CTAP on DPDPE-induced antinociception between naive and morphine-tolerant mice at the spinal site

AntagonistsAD50 of DPDPE (95% confidence limits)
NaiveTolerant
nmol/mouse
NTI
 10 nmol/mouse21  (14–31)52  (15–32)
CTAP
 0.01 nmol/mouse5.8  (4.3–7.8)79  (40–156)
 0.05 nmol/mouse19  (11–31)232  (160–337)