Proceedings of The Physiological Society

University of Central Lancashire (2002) J Physiol 543P, S240

Communications

Evidence for anaesthetic-mediated effects on protein expression

A.J. Woodall and W. Winlow

University of Central Lancashire, Preston PR1 2HE, UK


Anaesthetics affect a range of cellular processes from membrane potential to free calcium concentration [Ca]i and ion channel activity. Some of these effects may play important roles in the mechanics of the production and maintenance of anaesthesia (Kress et al. 1987). Of equal importance are long- and short-term side effects of anaesthetics, including memory loss, disorientation and confusion. Extracellular regulated kinase 1 and 2 (ERKs 1 and 2) have been suggested to play roles in memory formation and synaptic plasticity (Cobb, 1999) and anaesthetic-regulated changes in phosphorylated ERK1 and 2 have already been shown (Woodall & Winlow, 2002). Here we examine the effects of the two general anaesthetics thiopentone, a barbiturate, and halothane, a volatile anaesthetic, on the expression of total ERK (tERK1 and 2) in PC12 cells.

PC12 cells were routinely maintained in DMEM supplemented with 10 % horse serum, 5 % fetal calf serum, 2 mM L-glutamine, 40 u ml-1 penicillin and 100 µg ml-1 streptomycin as previously described (Woodall and Winlow, 2002). Cells were continuously exposed to anaesthetic for set periods of time between 20 and 140 min, run on an SDS-PAGE gel and blotted to detect total ERK1 and 2. All data were statistically analysed using ANOVA and Tukey's post-hoc test and are presented as means ± S.E.M.

Thiopentone (500 µM) significantly increased the amount of tERK between 20 and 100 min constant exposure. After 20 min tERK had increased from 100 ± 1.9 % of control to 232.6 ± 18.7 % (P = 0.002, n = 4). After 120 min continuous exposure there was no significant difference from control levels. Halothane (2 %) also significantly increased tERK this time between 20 and 140 min constant exposure. After 20 min halothane expression of tERK had increased from 100 ± 1.9 to 211.1 ± 4.5 % (P = 0.001, n = 4).

These results demonstrate that anaesthetics have a significant action on protein expression in this cell line. Changes in the expression of ERKs may lead to the alteration of gene regulation, cellular plasticity and cell survival responses as well as memory formation and mitogenic responses in the cell (Cobb, 1999).Therefore it is possible that these anaesthetic-induced changes in the protein may lead to effects on these CNS activities.

Where applicable, experiments conform with Society ethical requirements