Oreopoulos D G, Lindeman R D, VanderJagt D J, Tzamaloukas A H, Bhagavan H N, Garry P J
Department of Medicine, University of New Mexico School of Medicine, Albuquerque 87131.
J Am Coll Nutr. 1993 Oct;12(5):537-42. doi: 10.1080/07315724.1993.10718349.
To determine if the lower plasma ascorbic acid concentrations observed in males compared to females, and in the elderly in general, might be due to differences in renal clearances of ascorbic acid, tubular maximum reabsorptions (TmAA) and renal thresholds for ascorbic acid were determined on older (10 male, 10 female, aged 70-86 years) and younger (3 male, 5 female, aged 26-59 years) subjects. The mean TmAA for men was 1.54 +/- 0.29 and for women 1.39 +/- 0.33 mg/minute/100 mL glomerular filtration rate (p > 0.05). The mean renal threshold for men was 1.51 +/- 0.25 and for women 1.26 +/- 0.16 mg/dL (p < 0.02). Neither was affected by age. If differences in TmAA and renal threshold were to explain the lower plasma ascorbic acid concentrations observed in males, both values should have been lower than in females. The ability of women to maintain higher plasma ascorbic acid concentrations than men, and young higher than elderly, cannot be explained by differences in the renal handling of ascorbic acid.
为了确定与女性相比男性以及一般老年人中观察到的较低血浆抗坏血酸浓度是否可能归因于抗坏血酸肾清除率的差异，我们测定了老年（10名男性、10名女性，年龄70 - 86岁）和年轻（3名男性、5名女性，年龄26 - 59岁）受试者的抗坏血酸肾小管最大重吸收量（TmAA）和抗坏血酸肾阈值。男性的平均TmAA为1.54±0.29，女性为1.39±0.33毫克/分钟/100毫升肾小球滤过率（p>0.05）。男性的平均肾阈值为1.51±0.25，女性为1.26±0.16毫克/分升（p<0.02）。两者均不受年龄影响。如果TmAA和肾阈值的差异能够解释男性中观察到的较低血浆抗坏血酸浓度，那么这两个值都应该低于女性。女性比男性能够维持更高血浆抗坏血酸浓度，年轻人比老年人更高，这无法用抗坏血酸肾脏处理的差异来解释。
