Acta Medica Medianae (Oct 2003)
THE EFFECTS OF Na-ASCORBATE ON ASCORBATE CONCENTRATION IN THE PLASMA AND TISSUES
Abstract
Male guinea pigs of a Hartley-derived strein, a mean starting weight of 325 g + 70 g (s.d.), immunized with bovine serum albumine, were studied in animals maintained on various amount of ascorbic acid for 28 days. Animals were paid-fed on ascorbate-free diet (standard ''dry'' meal (Wagner Guinea Pig Diet). The animals were immunized with bovine serum albumuine (BSA, Miles) 0.2 mg being administered in complete Freund's adjuvans on day 0 (0.025 mg /foot pad and 0.1 mg in the nuchal skin) and again on day 14 in 1% saline into the nuchal skin. The animals were separated into five categories of five animals each and put on a daily schedule of intraperitoneal injections of 0, 10, 25, 100 i 250 mg Na-ascorbate (Bronson). Blood was taken by cardiac puncture from each animal on experimental days 0, 14 and 28. At the end of experiment all animals were anesthetized and tissue samples were taken for evaluation of vitamin C with Zannoni methods. The immunized guinea pigs receiving no supplementation showed a reduction in ascorbic acid concentration of 59% at 14 days to 67% at 28 days. In the meantime, no difference between the 10 and 25 mg doses in relative change. Guinea pigs receiving the mega doses (100 mg and 250 mg/day) exhibited increased plasma levels, the former showing a greater increase than latter. At the end of the experiment the gain in the 100 mg group had dropped to 12%, but in the 250 mg group it continued to raise. Of greater significance than the plasma levels are the ascorbate concentrations measured in various tissues of selected animals that had been maintained for 28 days on these ascorbate regimens. Intraperitoneal administration of Na-ascorbate a rapid increase of ascorbic acid plasma concentration. The greatest the ascorbate concentrations was obtained in the case of the adrenal (95.3), pituitary (89.1) and spleen (29.7) per 100 g in the respective cases. Under the same circumstances the ascorbate concentrations in the brain and in the eye dropped only to 20% of the control value.