N. Dursun et al., THE EFFECT OF ZINC-DEFICIENCY ON MORPHINE ANTINOCICEPTION, Research communications in alcohol and substances of abuse, 16(1-2), 1995, pp. 47-52
The present study is designed to examine the effect of zinc deficiency
and possible role of zinc on morphine antinociception in mice. Theref
ore, mice were divided into four groups: 1) Zinc-deficient, 2) Pair-fe
d, 3) Control-morphine, and 4) Control-saline groups. Mice were fed du
ring eight weeks of the study. At the end of this period 1.5 mg.Kg(-1)
morphine was injected into mice except for the control-saline group a
nd 20 min later the antinociceptive effect of morphine was evaluated b
y tail immersion test. In spite of morphine injection, the tail withdr
awal latency of zinc-deficient mice was not different from control-sal
ine (p > 0.05). The same parameter in pair-fed group was significantly
different from control-saline (p < 0.05) and control-morphine groups.
On the other hand, there was no difference between pair-fed and contr
ol-morphine groups (p > 0.05). In addition, plasma zinc levels of zinc
-deficient mice were significantly lower than other groups (p < 0.05).
Our results suggest that zinc deficiency may prevent the antinocicept
ive effects of morphine. Zinc may be necessary in physiologic range fo
r morphine to exert antinociception activity.