In rats, single intravenous doses of folic acid induce damage to renal tubular epithelium,
deposition of folic acid in tubular lumens, increase in wet kidney weight, oliguria and
interstitial connective tissue proliferation. Separation of the nephrotoxic and obstructive
effects of folic acid was attempted by pretreatment with NH 4 Cl or NaHCO 3. These effects
of folic acid were unaltered by pretreatment with NH 4 Cl and there was, in addition,
accumulation of eosinophilic droplets in papillary collecting duct epithelium. After …