Abstract
Phencyclidine (1-(1-phenylcyclohexyl) piperidine, CAS 956-90-1, PCP, I) and its derivatives
have shown many analgesic effects. In this research, a new derivative of PCP (1-[1-(2-methylphenyl)(cyclohexyl)]-3-piperidinol,
PD, II) was synthesized and its analgesic (acute and chronic pains) effects were examined
on rats using tail immersion (as a model of acute thermal pain) and formalin (as a
model of acute and chronic chemical pain) tests and the results are compared to PCP
and control groups.
The results indicated that II produces higher analgesic effects in the tail immersion
test compared to the PCP and control groups, with a marked and significant increase
in tail immersion latency for the doses 1, 5 and 10 mg/kg. The formalin test showed
that PD (II) is not effective in acute chemical pain (phase I, 0–5 min after injection)
in all doses but chronic pain (initial-phase II, 15–40 min after injection) is significantly
attenuated by this compound compared to PCP and saline (control) in doses of 5 and
10 mg/kg.
It is concluded that II is effective in acute thermal (in all doses) and chronic (doses
of 5 and 10 mg/kg) pains; however, it is not effective in acute chemical pain compared
to PCP and control.
Key words
Acute and chronic pain - Analgesics - CAS 956-90-1 - Formalin test - Phencyclidine,
derivative - Tail immersion test