Effects of purified newly developed botulinum neurotoxin type A in rat prostate.
OBJECTIVE
To investigate the efficacy of a newly purified neurotoxin (NTX) in male rat prostates. Several reports have suggested that intraprostatic injection of botulinum toxin type A has demonstrated efficacy against symptomatic benign prostatic hyperplasia. NTXs associate with nontoxic components and form large complexes designated "progenitor toxins." In general, progenitor toxins are used, because they are easily obtained and are more stable than NTXs. However, they have side effects for some patients in whom anti-progenitor toxins, including anti-NTX antibodies, are produced after several injections. We purified NTXs without their nontoxic components using a simple procedure.


METHODS
Adult male Sprague-Dawley rats were injected with 5 U of NTX or saline into their prostates, which were harvested and weighed after 1 or 4 weeks. The effects of the NTX on the prostate were histologically and immunohistochemically studied using hematoxylin-eosin, synaptophysin, and terminal deoxynucleotidyl-mediated deoxyuridine triphosphate nick end labeling staining.


RESULTS
In the NTX-treated rats, the prostate weight was reduced and atrophy and diffuse apoptosis were observed. Moreover, synaptophysin-positive cells in the epithelium were decreased after NTX injection.


CONCLUSIONS
Intraprostatic NTX injection induces prostate apoptosis and atrophic change in the rat prostate. These results suggest that NTX injection might be a promising material for treatment of patients with benign prostatic hyperplasia.
Nishiyama
Yasuhiro
Y
Department of Urology, Okayama University Graduate School of Medicine and Dentistry, Japan. nishiyasu329@yahoo.co.jp
Yokoyama
Teruhiko
T
Tomizawa
Kazuhito
K
Okamura
Kikuo
K
Yamamoto
Yumiko
Y
Matsui
Hideki
H
Oguma
Keiji
K
Nagai
Atsushi
A
Kumon
Hiromi
H
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001284:Atrophy; D019274:Botulinum Toxins, Type A / Q000302:isolation & purification / Q000494:pharmacology*; D008297:Male; D009498:Neurotoxins / Q000494:pharmacology*; D011467:Prostate / Q000187:drug effects* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley
D009498:Neurotoxins; D019274:Botulinum Toxins, Type A