Jones C A, Refsal K R, Lippert A C, Nachreiner R F, Schwacha M M
Department of Small Animal Clinical Sciences, Michigan State University, East Lansing 48824.
Domest Anim Endocrinol. 1990 Oct;7(4):559-72. doi: 10.1016/0739-7240(90)90013-p.
In Experiment 1, voided urine samples were collected from 12 adult dogs at 0500, 1400, and 2200 hr for 4 days. Cortisol was measured in unextracted urine by radioimmunoassay, creatinine by spectrophotometry, and the cortisol/creatinine ratio (UCCR) was calculated for each sample. There was considerable variation both within and among dogs in UCCR but there was no consistent time of day fluctuation in UCCR. In Experiment 2, these dogs were randomly assigned to 1 of 4 groups. The groups received each of 4 treatments (saline, dexamethasone, ACTH gel, and aqueous ACTH) at 7 day intervals in Latin square design. All urine was collected from 0 through 8 hr. Blood samples were collected at 20 minute intervals from 0 through 8 hr. Plasma cortisol exposure was determined by quantifying area under the curve (AUC). UCCR measurement was shown to differentiate basal from elevated, but not lowered, cortisol secretion. A positive linear relationship between UCCR and AUC was seen for all treatments except dexamethasone. These results indicate that changes in cortisol secretion are reflected in changes in UCCR, but measurement of UCCR may lack sensitivity to differentiate basal from reduced states of cortisol secretion. In Experiment 3, urine was collected daily before and during induction therapy with o,p'-DDD from dogs with pituitary-dependent hyperadrenocorticism. Successful suppression of the adrenal glands was accompanied by a progressive decrease in UCCR. There was considerable variation in the rate of adrenal suppression.
在实验1中，在4天内于05:00、14:00和22:00从12只成年犬收集晨尿样本。通过放射免疫分析法测定未提取尿液中的皮质醇，用分光光度法测定肌酐，并计算每个样本的皮质醇/肌酐比值（UCCR）。犬只个体内和个体间的UCCR存在相当大的差异，但UCCR在一天中没有一致的时间波动。在实验2中，这些犬只被随机分为4组中的1组。各组以拉丁方设计，每隔7天接受4种治疗（生理盐水、地塞米松、促肾上腺皮质激素凝胶和促肾上腺皮质激素水剂）中的一种。在0至8小时收集所有尿液。在0至8小时每隔20分钟采集血样。通过量化曲线下面积（AUC）来确定血浆皮质醇暴露量。结果显示，UCCR测量可区分基础皮质醇分泌与升高的皮质醇分泌，但不能区分降低的皮质醇分泌。除地塞米松外，所有治疗的UCCR与AUC之间均呈正线性关系。这些结果表明，皮质醇分泌的变化反映在UCCR的变化中，但UCCR测量可能缺乏区分基础皮质醇分泌状态与降低状态的敏感性。在实验3中，对垂体依赖性肾上腺皮质功能亢进犬在使用o,p'-滴滴滴诱导治疗前和治疗期间每天收集尿液。肾上腺成功被抑制伴随着UCCR的逐渐降低。肾上腺抑制率存在相当大的差异。
