Structural changes in the human stria vascularis induced by aminoglycosides and loop diuretics

Area of Science:

• Ototolaryngology
• Pharmacology
• Cell Biology

Background:

• The stria vascularis is crucial for maintaining the cochlear environment.
• Drug-induced ototoxicity is a significant clinical concern, particularly with loop diuretics and aminoglycosides.
• Understanding the human stria vascularis' response to these drugs is vital for predicting and preventing hearing loss.

Purpose of the Study:

• To examine the ultrastructural effects of loop diuretics and aminoglycoside antibiotics on the human stria vascularis.
• To compare human tissue changes with those observed in animal models of ototoxicity.
• To validate the use of animal models for predicting human ototoxicity.

Main Methods:

• Human stria vascularis tissues from normal controls and patients treated with loop diuretics, aminoglycosides, or both were analyzed.
• Scanning and transmission electron microscopy were employed.
• Tissues were preserved via perilymphatic perfusion fixation within one hour of death.

Main Results:

• Normal human stria vascularis ultrastructure is similar to that of experimental animals.
• Loop diuretics induced changes indistinguishable from those in animal models.
• Aminoglycosides caused alterations, potentially influenced by concurrent renal failure.
• Combined treatment showed a spectrum of mild to severe ultrastructural changes.

Conclusions:

• Loop diuretics and aminoglycosides induce characteristic ultrastructural changes in the human stria vascularis.
• Observed human changes closely resemble those in animal models, supporting their predictive value.
• These findings reinforce the utility of animal models in assessing drug-induced ototoxicity for human health.