Gentamicin administered during gestation alters glomerular basement membrane development

Area of Science:

• Nephrology
• Developmental Biology
• Toxicology

Background:

• Gentamicin is an antibiotic known to cause nephrotoxicity.
• Previous studies indicated gentamicin-induced kidney damage in neonates.
• The long-term effects of gestational gentamicin exposure on glomerular development were unclear.

Purpose of the Study:

• To investigate the long-term effects of prenatal gentamicin exposure on the glomerular basement membrane (GBM) ultrastructure.
• To analyze the arrangement of anionic sites and urinary proteins in offspring at different ages.
• To determine if gestational gentamicin exposure causes permanent alterations in kidney structure and function.

Main Methods:

• Pregnant Wistar rats were administered gentamicin intraperitoneally.
• Offspring were studied at 1 day and 12 months of age (control vs. exposed).
• Methods included electron microscopy, analysis of anionic sites (heparan sulfate proteoglycans), kidney tissue composition (hydroxyproline, sulfate, hexuronic acid), and urinary protein electrophoresis.

Main Results:

• Neonatal exposure showed similar glomerular differentiation but increased lamina densa and anionic sites in the GBM.
• Adult offspring exhibited altered juxta-medullary glomeruli with larger GBMs and increased anionic sites.
• Prenatal gentamicin exposure led to abnormal kidney composition and altered urinary protein profiles in both neonates and adults.

Conclusions:

• Gentamicin administered during pregnancy causes permanent structural alterations in the glomerular basement membrane.
• These alterations involve changes in GBM layers and anionic site distribution, potentially due to perturbed protein metabolism.
• The altered glomeruli represent a risk factor for developing kidney disease throughout life.