Pharmacologic suppression of experimental abdominal aortic aneurysms: acomparison of doxycycline and four chemically

J A Curci1, D Petrinec, S Liao

  • 1Department of Surgery, Washington University School of Medicine, St Louis, MO 63110, USA.

Abstract

Insights

Tetracycline derivatives, including doxycycline and chemically modified tetracyclines (CMTs), effectively suppressed the development of abdominal aortic aneurysms (AAAs) in a rat model by preserving medial elastin.

Area of Science:

  • Cardiovascular Research
  • Pharmacology
  • Biochemistry

Background:

  • Matrix metalloproteinases (MMPs) are implicated in the medial elastin degradation observed in abdominal aortic aneurysms (AAAs).
  • Tetracycline antibiotics possess MMP-inhibiting properties, suggesting potential therapeutic applications for AAAs.

Purpose of the Study:

  • To compare the efficacy of doxycycline and novel chemically modified tetracyclines (CMTs) in preventing elastase-induced AAA formation in rats.
  • To investigate the dose-dependent effects of doxycycline on AAA development.

Main Methods:

  • Induction of AAA in male Wistar rats via intraluminal elastase perfusion.
  • Treatment with saline, varying doses of doxycycline, or four distinct CMTs via subcutaneous injections for seven days.
  • Assessment of aortic diameter changes, histological examination of aortic tissues, and MMP activity analysis using gelatin zymography.

Main Results:

  • Elastase perfusion significantly increased aortic diameter and induced AAA in 83% of control rats.
  • Doxycycline demonstrated dose-dependent inhibition of aortic dilatation, with maximal effect at >30 mg/kg/day.
  • CMTs (CMT-3, CMT-4, CMT-7, CMT-8) at 15 mg/kg/day showed efficacy comparable to doxycycline, inhibiting AAA development and preserving medial elastin.

Conclusions:

  • Tetracycline derivatives effectively suppress AAA development in a rat model, independent of their antibiotic properties.
  • The aneurysm-suppressing effects are linked to the preservation of medial elastin fibers.
  • MMP-inhibiting tetracyclines represent a promising novel pharmacologic strategy for AAA suppression.