Effect of pCPA on nicotine-induced analgesia.

This study investigated the effect of para-chlorophenylalanine (pCPA), on nicotine-induced analgesia. pCPA reduces physiological levels of 5-HT, a neurotransmitter that has been linked to pain. The effects of naloxone HCl and mecamylamine HCl on this analgesia were also assessed. Subjects were 24 albino rats. Each group of eight rats was injected subcutaneously (SC) with nicotine sulphate, followed by an intraperitoneal (IP) injection of one of the potential antagonists. Behavioral analgesia was assessed using the tail-flick test. Data analysis revealed that pCPA did not affect nicotine-induced analgesia. Consistent with past research, naloxone also had no effect, and mecamylamine effectively eliminated this analgesia. The results are interpreted in light of current knowledge of this behavioral analgesia and pain perception, in general.