Tsao C S, Leung P Y
Linus Pauling Institute of Science and Medicine, Palo Alto, CA 94306.
J Nutr. 1988 Jul;118(7):895-900. doi: 10.1093/jn/118.7.895.
Male guinea pigs received sodium ascorbate solution [equivalent to 1 g ascorbic acid/(kg body weight.d)] by intraperitoneal injection for 4 wk. During the ascorbic acid treatment period, plasma and urinary ascorbic acid levels rose markedly. Three weeks after the ascorbic acid treatment was withdrawn, mean urinary ascorbic acid levels were significantly lower than their corresponding basal levels. At both 2 and 5 wk after withdrawal of ascorbic acid treatment, mean plasma ascorbic acid levels were below normal. The results indicate that these animals had experienced a transient withdrawal effect after administration of large doses of ascorbic acid that lasted about 1 wk. This, in turn, indicates that the rate of ascorbic acid turnover was probably increased during treatment, and this effect persisted even after the ascorbic acid was withdrawn. Examination of data from each individual experimental animal revealed that the pattern of urinary ascorbic acid excretion after the withdrawal of large doses of ascorbic acid varied from animal to animal. Among the twelve experimental guinea pigs, seven had abnormally low urinary ascorbic acid levels 2-4 wk after the withdrawal of the large doses of ascorbic acid.
雄性豚鼠通过腹腔注射接受抗坏血酸钠溶液[相当于1克抗坏血酸/（千克体重·天）]，持续4周。在抗坏血酸治疗期间，血浆和尿中抗坏血酸水平显著升高。停止抗坏血酸治疗3周后，尿中抗坏血酸平均水平显著低于相应的基础水平。在停止抗坏血酸治疗后的第2周和第5周，血浆抗坏血酸平均水平均低于正常水平。结果表明，这些动物在大剂量抗坏血酸给药后经历了持续约1周的短暂撤药效应。这反过来表明，抗坏血酸周转速率在治疗期间可能增加，并且即使在停止抗坏血酸给药后这种效应仍然存在。对每只实验动物的数据检查显示，大剂量抗坏血酸撤药后尿中抗坏血酸排泄模式因动物而异。在12只实验豚鼠中，7只在大剂量抗坏血酸撤药后2 - 4周尿中抗坏血酸水平异常低。
