The effect of intracerebroventricular administration of CCK receptor agonist and antagonist in nerve-Iigated mice

In the present study the effect of intracerebroventricular (ICV) injection of cerulein, an agonist of CCK receptor and proglumide, a receptor antagonist for hyperalgesia induced by sciatic nerve ligation were investigated in mice. Subcutaneous administration of morphine caused anti-nociception in both intact and nerve-ligated mice. However, the response to opioids was lower in ligated mice as compared to the intact animals. Cerulein induced antinociception only in the nerve-Iigated animals. Combination of cerulein with morphine elicited higher response in both intact and ligated animals. However, the induced response was much prominent in ligated animals. Proglumide alone did not elicit any response in both groups. The antagonist decreased the response of cerulein in the non-ligated mice. In addition a low dose of proglumide in combination with cerulein induced antinociception in the ligated mice. It can be concluded that CCK receptor-related