超音波診断装置を用いた覚醒及びケタミン不動化カニクイザルにおける腎血管抵抗値の測定に関する研究

抄録

Measurement of the renal resistive index (RRI) is one of the standard diagnostic procedures for assessing kidney disability clinically. To establish a practical RRI measurement procedure in cynomolgus monkeys (Macaca fascicularis) which utilized in conventional toxicology studies, RRI was measured by ultrasonography in the spine position in conscious and ketamine-immobilized monkeys. The RRI of conscious monkeys and ketamine-immobilized monkeys could be measured consistently without excessive abdominal or thoracic movement. Consequently, the variability of the RRI in conscious monkeys was comparable to that in ketamine-anesthetized monkeys. No sex difference in RRI was noted between the two conditions. The mean values and standard deviations (SD) of the RRI of 48 healthy monkeys (n = 24/sex) were 0.55 ± 0.07 and 0.50 ± 0.05, under conscious and ketamine-immobilized conditions, respectively. The RRI of ketamine-immobilized monkeys was significantly lower than that of conscious monkeys, correlating with the decreased blood pressure and heart rate. In a monkey model of cisplatin-induced acute renal injury, which was characterized histopathologically by minimal to mild renal tubular necrosis and regeneration, the RRI was increased beyond the cut off value (mean + 2SD, 0.68) associated with the progression of renal pathogenesis. The present results suggest that ultrasonographic measurement of the RRI in conscious monkeys would be a useful tool in conventional toxicology studies evaluating drug-induced renal injury.