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Dynamic expression of the myocardial sigma-1 receptor after doxorubicin cardiomyopathy using radioiodine-labeled 2-[4-(2-iodophenyl)piperidino]cyclopentanol (OI5 V) imaging

  • 0Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-Machi, Kanazawa, Ishikawa, 920-8641, Japan.
Annals of Nuclear Medicine +

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May 29, 2025

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May 29, 2025

View abstract on PubMed

Summary

This summary is machine-generated.

A novel radiotracer, 125I-OI5V, detected reduced sigma-1 receptor (σ1R) expression in rats with doxorubicin-induced cardiotoxicity. This decrease in σ1R may signal heart damage earlier than traditional ejection fraction measurements.

Area Of Science

  • Radiopharmaceutical chemistry
  • Molecular imaging
  • Cardiovascular toxicology

Background

  • Doxorubicin (DOX) is a potent chemotherapy agent with known cardiotoxic side effects.
  • Early detection of DOX-induced cardiotoxicity is crucial for patient management.
  • Sigma-1 receptor (σ1R) is implicated in cellular stress responses, including those in the heart.

Purpose Of The Study

  • To evaluate the expression of σ1R using the radiotracer 125I-OI5V in a rat model of DOX-induced cardiotoxicity.
  • To assess if σ1R expression changes can serve as an early biomarker for DOX-induced cardiotoxicity.

Main Methods

  • Wistar rats were administered DOX (2 mg/kg/week).
  • Cardiac function was assessed using 99mTc-MIBI SPECT, and renal function using 99mTc-DSMA scintigraphy.
  • Uptake of 125I-OI5V in various organs was measured at different time points post-DOX injection.

Main Results

  • DOX administration led to increased left ventricular cavity volume and decreased ejection fraction at seven weeks.
  • Renal function significantly declined after seven weeks.
  • 125I-OI5V uptake decreased in tissues starting from five weeks post-DOX, with increased uptake in the blood and decreased uptake in the kidney.

Conclusions

  • The study confirmed altered σ1R expression following DOX injection.
  • A decline in σ1R expression, detected by 125I-OI5V, may precede functional changes like reduced ejection fraction.
  • 125I-OI5V shows potential as an early diagnostic marker for doxorubicin-induced cardiotoxicity.

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