Supplementary Material for: The Effects of Early Postnatal Diuretics Treatment on Kidney Development and Long-Term Kidney Function in Wistar Rats

Background: Diuretics are administered to neonates to control fluid balance. We studied whether clinical doses affected kidney development and function and whether extrauterine growth retardation (EUGR) could be a modulator. Methods: Wistar rats were cross-fostered in normal food or food restricted litters at postnatal day (PND) 2 and treated daily with 0.9% NaCl, 5 mg/kg furosemide or 5 mg/kg hydrochlorothiazide (HCTZ) up to PND 8. Kidneys were evaluated on proliferation, apoptosis and a set of mRNA target genes at PND 8, glomerular- and glomerular generation count at PND 35, clinical pathology parameters at 3- and 9 months, neutrophil gelatinase-associated lipocalin at PND 8, 3 and 6 months, monthly blood pressure from 3 months onward and histopathology at study end. Results: Treatment with furosemide or HCTZ did not have relevant effects on measured parameters. EUGR resulted in lower body weight from day 3 onwards (-29% at weaning; p Conclusion: Furosemide and HCTZ did not influence kidney development or function when administered in a clinically relevant dose to rat pups at a stage of ongoing nephrogenesis. EUGR led to impaired kidney development but did not modify furosemide or HCTZ findings.