ELASTOMERS AS ANALOGUES OF ANAESTHETIC RECEPTORS

Elastomers are polymers of high molecular weight having flexible long chain molecules, the structure of which allows free rotation about certain chemical bonds in the chain. Elasticity is conferred by their mobile bonds and by cross-links between the chains which build up a three-dimensional network and resist flow. Anaesthetic agents are soluble in elastomers and cause swelling and also a reduction in elasticity. It has been suggested that the molecular changes in elastomers produced by anaesthetics might resemble those taking place at the sites of action of general anaesthetics. We therefore conducted experiments to correlate the effects of anaesthetics on various elastomers with an index of anaesthetic potency (MAC). The correlation for silicone rubber was poor but that for natural rubber was better. Consideration of molecular changes in elastomers may have implications for molecular mechanisms of general anaesthesia. In addition these experiments suggest that it is possible to construct an instrument ble of measuring anaesthetic potency direct (an “MAC meter”), in either a gaseous or a liquid medium.