Therapeutic manipulation of peroxynitrite attenuates the development of opiate-induced antinociceptive tolerance in mice
J. Clin. Invest. 117:11 doi:10.1172/JCI32420 [Go to this article.]

Figure 4
On day 5 the acute injection of morphine (3 mg/kg) (vehicle group) but not its vehicle (naive group) in animals that received saline over 4 days did not lead to nitration of the GT GLT-1 or GS in dorsal horn tissues as measured by immunoprecipitation.

(A and C) On the other hand, acute administration of morphine in the morphine group led to significant nitration of GLT-1 (A) and GS (C). Coadministration of morphine over 4 days with l-NAME (10 mg/kg/d), MnTBAP^3– (10 mg/kg/d), or FeTM-4-PyP⁵⁺ (30 mg/kg/d) prevented the nitration of both GLT-1 and GS. (B and D) When compared with the naive or vehicle groups, repeated administration of morphine did not change the total amount of GLT-1 (B) or GS (D) in dorsal horn tissues as measured by Western blotting analysis. Gels are representative of gel results obtained from 6 animals. A composite (n = 6) of the densitometry data resulting from these experiments is shown in Table 1.