Morphological alterations in cultured neuromuscular tissue induced by two anesthetic agents.

A diversity of pathogenic effects was observed in two complementary culture systems following their exposure to the anesthetic agents. Thiopental sodium and ketamine hydrochloride. The cytotoxic effects of both agents in these two culture types were reversible and dose-related. In organotypic spinal cord slice cultures, thiopental sodium caused general toxicity but no demyelination, while ketamine hydrochloride induced, to a varied extent, damage of the myelin sheath and degeneration of mitochondria into multilamellar bodies. In autologous nerve-muscle co-cultures both anaesthetic agents caused the arrest of muscle contractions. However, when added to skeletal muscle cultures, the drugs differed in their effect. Thiopental sodium did not inhibit spontaneous muscle contractions indicating, as in the case of Tubocurarine, a direct effect of the drug on the neuromuscular junction. Ketamine hydrochloride, in contrast, arrested spontaneous muscle contractions, implying that it did not directly affect the neuromuscular synapse.