The antinociceptive activities of oxotremorine, physostigmine and dyflos

Oxotremorine and physostigmine caused dose-related increases in the hot plate reaction time (HPRT) of mice, but dyflos did not. Physostigmine did not potentiate a low dose of oxotremorine (0.025 mg/kg) in the HPRT test, but some potentiation of higher doses of oxotremorine (0.05 and 0.1 mg/kg) may have occurred. Dyflos did not potentiate any dose of oxotremorine. Physostigmine and dyflos inhibited mouse brain cholinesterase but oxotremorine was without effect. The relation between change of HPRT and cholinesterase inhibition was different for physostigmine and dyflos.