Effects of terpineol on the compound action potential of the rat sciatic nerve.

M.R Moreira,A.A.C Albuquerque,M.S Lopes,G.M.P Cruz,J.H Leal-Cardoso

doi:10.1590/s0100-879x2001001000015

Abstract

Terpineol, a volatile terpenoid alcohol of low toxicity, is widely used in the perfumery industry. It is an important chemical constituent of the essential oil of many plants with widespread applications in folk medicine and in aromatherapy. The effects of terpineol on the compound action potential (CAP) of rat sciatic nerve were studied. Terpineol induced a dose-dependent blockade of the CAP. At 100 microM, terpineol had no demonstrable effect. At 300 microM terpineol, peak-to-peak amplitude and conduction velocity of CAP were significantly reduced at the end of 180-min exposure of the nerve to the drug, from 3.28 +/- 0.22 mV and 33.5 +/- 7.05 m/s, respectively, to 1.91 +/- 0.51 mV and 26.2 +/- 4.55 m/s. At 600 microM, terpineol significantly reduced peak-to-peak amplitude and conduction velocity from 2.97 +/- 0.55 mV and 32.8 +/- 3.91 m/s to 0.24 +/- 0.23 mV and 2.72 +/- 2.72 m/s, respectively (N = 5). All these effects developed slowly and were reversible upon 180-min washout.

Highlights

After a stabilization period of 60 min, during which stable peak-to-peak compound action potential (CAP) amplitude recording was performed for at least 30 min, the bathed nerve segment was exposed to pharmacological agents for 180 min
The number of observations is given in parentheses. aQuantification at 180 min. bControl (0.25% DMSO), at the 360th min after stabilization. cN = 4 because in one experiment CAP blockade was total after 120 min
At 100 μM, terpineol did not alter the CAP (Table 1 and Figure 1), but at doses of 300 and 600 μM, peak-to-peak amplitude and conduction velocity were significantly reduced in a dose-dependent manner (Table 1 and Figure 1)

Summary

Introduction

After a stabilization period of 60 min, during which stable peak-to-peak CAP amplitude recording was performed for at least 30 min, the bathed nerve segment was exposed to pharmacological agents for 180 min. Nerves were normally used on the day of dissection; in some experiments they were stored overnight in cold (5oC) Lockes solution for use on the following day. At such concentration DMSO did not alter CAP parameters.

Results

Conclusion