Single injection techniques in determining age-related changes in porcine renal function

Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were determined in 32 anaesthetised female Large pigs, aged 4-24 months, from the plasma disappearance curves of [99mTc]DTPA and [131I]hippuran respectively. Clearance was also monitored by external counting over the heart. GFR and ERPF increased markedly with age in pigs up to 12 months old, reaching mean values of 242.06 +/- 5.89 and 919.39 +/- 79.01 mL/min. In pigs aged 12-24 months ERPF increased slightly, but renal function remained essentially unchanged after 1 yr of age. These results for renal function were similar to previous estimates, using continuous infusion techniques inferring that GFR and ERPF could be accurately monitored using single injection procedures.