Dermal Lactic Acid Content and Development of the Local Shwartzman Reaction

¹ From the Laboratory of Chemical Pharmacology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland

Changes in metabolism and lactic acid content of prepared skin were studied in relation to intradermal dose level, polysaccharide preparation used, effect in tolerant rabbits and incidence of dermal Shwartzman reactions which could be provoked subsequently by a standard intravenous injection of a Shwartzman-active polysaccharide preparation from S. marcescens. Respiration of skin was not altered significantly by polysaccharide injection, although glycolysis was increased. The change in lactic acid content of skin varied directly with intradermal dose of bacterial polysaccharide. Doses adequate to produce significant increase in skin lactic acid also were adequate to prepare for subsequent development of the Shwartzman reaction in 80% of rabbits. Further increase in dose and skin lactic acid did not increase the incidence of positive reactions. Comparable incidence of Shwartzman reactions and increase in skin lactic acid were caused by intradermal injection of a plant polysaccharide (inactive as provocative material) but not by heat-inactivated bacterial polysaccharide. In tolerant rabbits, skin lactic acid was increased significantly by intradermal injection of bacterial polysaccharide but no Shwartzman reactions could be provoked subsequently.