Comparison between intraperitoneal and subcutaneous phencyclidine administration in Sprague-Dawley rats: a locomotor activity and gene induction study.
Progress in neuro-psychopharmacology & biological psychiatry February 15, 2008 Mikhail Kalinichev, Melanie J Robbins, Elizabeth M Hartfield et al.
In a rat model of acute psychosis induced by phencyclidine (PCP), the drug's effects on movement and gene expression depend on how it is given. Adult male rats received PCP either injected into the abdomen or under the skin. PCP given under the skin produced stronger and longer-lasting hyperactivity, higher drug levels in blood and brain, and greater activation of several immediate early genes in the prefrontal cortex compared to injection into the abdomen. The differences in drug concentration appeared within 30 minutes and lasted up to 4 hours. The subcutaneous route provides a more robust and consistent model for studying acute psychosis.