Age-related changes in albumin elimination in female WAG/Rij rats

Albumin elimination rates were determined in 3-, 12-, 24- and 36-month-old female WAG/Rij rats. No change in elimination half-life was found with age. However, as there was an increase in the whole-body albumin pool, a concomitant increase in albumin clearance was observed at between 12 and 36 months of age. It was concluded that the increase in clearance between 12 and 24 months of age was only due to a change in the animal's physiology, whereas between 24 and 36 months of age it was also due to changes in the albumin molecule. The age-related changes in albumin clearance were thought not to be caused by changes in the albumin excretion via the urine or via the gastrointestinal tract.