Chronical treatment with sildenafil causes Achilles tendinopathy in rats.

Abstract

AIMS: The primary goal was to assess the effects of chronic sildenafil treatment over the Achilles tendons in rats. MAIN METHODS: Animals were divided into two groups, control and sildenafil administration (n = 5). After 60 days, the tendons were subject to biochemical and image analysis to compare tendons between the groups: collagen I and decorin content, polarisation microscopy and birefringence analysis, and tissue zymography. KEY FINDINGS: The animals exposed to sildenafil presented a much less organised tendon matrix, with reduced collagen I and non-collagenous protein content and a much higher decorin content. SIGNIFICANCE: The results observed in the animals can be characterised as tendinopathy, a condition not yet described as a sildenafil side effect.