title: The effect of variations in vitamin C intake on the cellular immune response of guinea pigs.
abstract: The uptake of tritiated thymidine by isolated peripheral blood lymphocytes obtained from male guinea pigs immunized with bovine serum albumin was studied in animals maintained on various amounts of Vitamin C for 28 days. Animals were pair-fed on ascorbate-free diet and were supplemented intraperitoneally with 0, 25, or 250 mg Na-ascorbate per day. Scorbutic animals lost weight rapidly during the final 2 experimental weeks. Their daily food intake averaged only 4 g/day during the last week; thus, pair-fed ascorbate-supplemented groups were also subjected to acute nutritional stress. Lymphocytes from guinea pigs receiving 250 mg Na-ascorbate per day incorporated in vitro the highest amounts of tritiated thymidine both in the absence of nonspecific mitogen and in the presence of concanavalin A or phytohemagglutinin. Responses to lipopolysaccharide were not conclusive. Total circulating white cells counts and relative numbers of T and B lymphocytes were assessed in a second study made under identical constraints. In scorbutic animals the percentage of B lymphocytes increased and that of T lymphocytes decreased continuously over the 4-week period. The opposite effect was observed in vitamin C-supplemented animals. These studies suggest that very high doses of ascorbate support elevated mitotic activity after 4 weeks of much reduced food intake.
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism / Q000494:pharmacology*; D003208:Concanavalin A / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D007111:Immunity, Cellular / Q000187:drug effects*; D007958:Leukocyte Count; D008070:Lipopolysaccharides / Q000494:pharmacology; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000502:physiology; D008297:Male; D008938:Mitosis; D010835:Phytohemagglutinins / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D008070:Lipopolysaccharides; D010835:Phytohemagglutinins; D003208:Concanavalin A; D001205:Ascorbic Acid; D013936:Thymidine