ラットにおける尿クレアチニン排泄速度に基づく尿流量推定の試み

• Published in: 日本薬理学会年会要旨集 p. 2-B-P-165
• Main Authors: 小口, 茜, 園田, 紘子, 川口, 珠実, 池田, 正浩
• Format: Journal Article
• Language: Japanese
• Published: 公益社団法人 日本薬理学会 2022
• Subjects: diuretic; urine
• ISSN: 2435-4953
• DOI: 10.1254/jpssuppl.96.0_2-B-P-165

Background: In humans, urine collection is accessible because of their altruistic behaviors. On the other hand, since animals urinate spontaneously, urine collection is difficult. In this study, because it has been known that the urinary creatinine excretion rate is almost constant in normal animals of similar age of the same species, we try to estimate the urine flow rate using the excretion rate in normal age-matched rats.Methods and Results:First, using urine collected from normal male SD rats, the urinary creatinine excretion rate was calculated by dividing the total urinary creatinine amount by the collection time, and the resulting average value was 8.95 micro g/min. Next, we calculated an estimated urinary flow rate (eUF) using the value mentioned above and urinary creatinine concentration in each individual, and compared the resulting eUF with an actual urinary flow rate (aUF) obtained by considering collected urine volume and time. When the body fluid balance of rat was altered by changing an amount of drinking water or a diuretic-treatment, a high positive correlation was observed between the aUF and eUF for either a change in water intake (r = 0.90) or a diuretic treatment group (r = 0.77). A similar result was obtained, when we calculated free water clearance using aUF and eUF, respectively (r = 0.89).Conclusion: These results suggest that the urine flow rate can be estimated from the average urinary creatinine excretion rate in normal rats. In the future, animal species differences and individuals with altered urinary creatinine excretion rate should be examined.