Pérez J F, Balcells J, Cebrián J A, Martín-Orúe S M
Departamento Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Zaragoza, Spain.
Br J Nutr. 1998 Mar;79(3):237-40. doi: 10.1079/bjn19980040.
The present study examined the endogenous urinary excretion of purine derivatives (PD; allantoin, uric acid and xanthine plus hypoxanthine) in fed animals. Four Rasa Aragonesa ewes fitted with simple cannulas in the rumen and proximal duodenum were used. Animals were given a lucerne (Medicago sativa) hay diet, as sole feed (A) or supplemented, respectively, with 220 (B), 400 (C), and 550 (D) g rolled barley grain/d following a 4 x 4 random factorial design. Duodenal flow of purine bases (PB) was determined by the dual-phase marker system. 15N was infused continuously into the rumen to label exogenous or microbial PB. Duodenal PB flow and urinary excretion of PD increased with digestible organic matter intake showing a constant recovery of duodenal PB. The isotope dilution of PD in urine samples confirmed the presence of an endogenous fraction, originating from tissues, that increased from 115.2 (SE 5.84) mumol/kg W0.75 for the basal diet to 304.2 (SE 7.6) mumol/kg W0.75 at the highest level of duodenal PB.
本研究检测了采食状态下动物嘌呤衍生物（PD；尿囊素、尿酸以及黄嘌呤加次黄嘌呤）的内源性尿排泄情况。选用了4只安装有瘤胃和十二指肠近端简易插管的阿拉贡纳绵羊。按照4×4随机析因设计，给动物分别饲喂紫花苜蓿（苜蓿）干草日粮作为唯一饲料（A组），或分别补充220（B组）、400（C组）和550（D组）克压碎大麦颗粒/天。采用双相标记系统测定十二指肠嘌呤碱（PB）流量。向瘤胃持续注入15N以标记外源性或微生物PB。十二指肠PB流量和PD的尿排泄量随可消化有机物摄入量的增加而增加，十二指肠PB呈现出恒定的回收率。尿样中PD的同位素稀释证实存在来自组织的内源性部分，其含量从基础日粮的115.2（标准误5.84）μmol/kg W0.75增加到十二指肠PB最高水平时的304.2（标准误7.6）μmol/kg W0.75。
