ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of intraprostatic injection of botulinum toxin A (BTX-A) on benign prostate hyperplasia (BPH) in rats.</p><p><b>METHODS</b>Models of BPH were established in adult male Sprague-Dawley rats by injection of testosterone propionate, and then divided into three BTX-A groups, injected with BTX-A into the ventral prostate at the doses of 5 U, 10 U and 20 U, a negative control group, injected with saline only, and a sham operation group, with 12 in each. The prostates of the animals were harvested at 2 or 4 weeks after the injection, their volumes and weights measured, histological changes examined by HE staining, and glandular and interstitial areas semi-quantified by the image analysis system.</p><p><b>RESULTS</b>Two rats died in the 20 U group within 3 days after BTX-A injection. Compared with the saline group, the 5 U, 10 U and 20 U BTX-A groups showed significant decreases in prostatic volume (P < 0.01, 0.01 and 0.05), weight, and glandular and interstitial areas as well as atrophic epithelia in the glandular tube at 2 weeks. These changes were lessened at 4 weeks, especially in the 5 U group.</p><p><b>CONCLUSION</b>Intraprostatic injection of BTX-A induces obvious atrophy and histological changes of the prostate, but meanwhile may potentially result in death at a large dose.</p>