Action of Narcotics on the Ameba by Means of Microinjection and Immersion.

Abstract

Comparative studies were made on the influence of the narcotics: ethyl alcohol, chloretone, ether, and chloroform on the protoplasm of Amoeba dubia, with special reference to their action on the plasmalemma.

Immersion Experiments: Very weak concentrations (subnarcotic) cause the Amebae to spread out and continue their movements in an expanded condition. This may be an effect of lowered surface tension. Ether in its narcotic concentration, approximately 2 per cent, produces a reversible gelation accompanied by the cessation of all movements. Lethal concentrations of all the narcotics cause the Ameba to round up followed by a sinking of its granules and a disintegration of the plasmalemma.

Injection Experiments: No narcotic effect was observed by injection into the interior of the Ameba. Chloretone in all concentrations increases the fluidity and streaming movements of the interior. Eighty per cent alcohol produces a coagulation which is localized and reversible, when small amounts are injected, and irreversible with large amounts. Pure chloroform and ether, when injected into the cytoplasm, form spherical drops which go into solution more rapidly than when injected into water. The protoplasm is irreversibly coagulated in the environment of the dissolving droplet. Chloroform is more potent than ether in causing coagulation. The irreversible coagula produced by the alcohol, chloroform and ether are pinched off by the living portion of the Ameba.

Local Application of the Narcotic on the Exterior of the Ameba: With saturated chloretone solution and 95 per cent alcohol no local effects were obtained. All the pseudopodia are withdrawn and the Ameba was converted into an actively moving limax form.

Concentrated, aqueous solution other produces a local blister on the plasmalemma with a coagulation of the cytoplasm at the base of the blister.