The Etiology of Basal Vacuolizations in Renal Tubular Epithelial Cells Evaluated in an Isolated Perfused Kidney Model

To determine whether basal lipid vacuolization characteristic of ketoacidosis could be induced with short-term hypertriglyceridemia, adult Sprague Dawley rat kidneys were perfused in an isolated perfused kidney model with, and without, 11.3 mM (10 g/L) of triglycerides in Krebs-Henseleit buffer, for 1 and 2 h (n = 5/group). Additional treatments included perfusion with triglycerides with 20 mM of β-hydroxybutyrate and 2 mM of acetoacetate (n = 5) and perfusion with triglycerides with 70 mM of glucose (n = 1). Basal vacuolization was produced in all groups, but differed in morphology to that reported in postmortem studies. There was no further increase in vacuolization after 2 h of perfusion compared to 1 h (p = 0.24), and the addition of ketones did not alter the morphology or extent of vacuolization. This study using an ex vivo model has confirmed that isolated hypertriglyceridemia is sufficient to cause basal lipid vacuolization in renal tubular epithelial cells, but with different morphology to vacuoles observed in lethal ketoacidosis at autopsy.