Haloperidol increases spreading and nitric oxide production in macrophages from tumor-bearing mice: a possible mechanism for its antitumoral effect.

Subcutaneous treatment with haloperidol (2.0 mg/kg) was found to increase both the percent of macrophage spreading and nitric oxide (NO) release in peritoneal macrophage from animals inoculated intraperitoneally with 5.0 x 10(6) Ehrlich ascites cells. This haloperidol-induced macrophage activation seems to be involved in its antitumoral effect since cotreatment with the iNOS inhibitor aminoguanidine was able to reverse the inhibitory effect of haloperidol on the development of the Ehrlich solid carcinoma.