Roch-Ramel F, Weiner I M
Am J Physiol. 1975 Dec;229(6):1604-8. doi: 10.1152/ajplegacy.1975.229.6.1604.
Anesthetized monkeys (Cebus albifrons) undergoing moderate mannitol diuresis were treated with infusions containing lithium urate to elevate the urate concentration in plasma to 45-68 mug/ml and containing the uricosuric drug, 2-nitroprobenecid, to enhance the renal clearance or urate. The urate/inulin clearance ratio was 0.55 +/- 0.03. When pyrazinoate was added to the infusion the clearance ratio fell to 0.26 +/- 0.02. Analysis of free-flow micropuncture samples revealed a major effect of pyrazinoate in the proximal tubule, although an additional, smaller action in the distal tubule could not be definitely excluded. When droplets containing [14C]urate and [3H]inulin were streaked on the surface of the left kidney more urate than inulin appeared in the urine from that kidney (but not the other) within the first 3 min after application. This "excess" excretion of urate could be largely eliminated by pretreatment with pyrazinoate. The results suggest that pyrazinoate inhibits secretion of urate in the proximal tubule.
对处于中度甘露醇利尿状态的麻醉猴（白额卷尾猴）进行治疗，输注含尿酸锂的溶液以使血浆尿酸浓度升高至45 - 68微克/毫升，并输注含促尿酸排泄药物2 - 硝基丙磺舒的溶液以提高尿酸的肾清除率。尿酸/菊粉清除率为0.55±0.03。当向输注液中加入吡嗪酸盐时，清除率降至0.26±0.02。对自由流动微穿刺样本的分析显示，吡嗪酸盐在近端小管有主要作用，尽管不能完全排除在远端小管有额外的较小作用。当将含[14C]尿酸和[3H]菊粉的液滴涂在左肾表面时，在涂抹后的前3分钟内，该肾（而非另一肾）的尿液中出现的尿酸比菊粉多。这种尿酸的“过量”排泄可通过吡嗪酸盐预处理在很大程度上消除。结果表明，吡嗪酸盐抑制近端小管中尿酸的分泌。
