Improvement in erectile dysfunction after insulin-like growth factor-1 gene therapy in diabetic rats.
OBJECTIVE
To determine whether adenoviral gene transfer of insulin like growth factor-1 (IGF-1) to the penis of streptozotocin (STZ)-induced diabetic rats could improve erectile capacity.


METHODS
THE STZ diabetic rats were transfected with AdCMV-betagal or AdCMV-IGF-1. These rats underwent cavernous nerve stimulation to assess erectile function and their responses were compared with those of age-matched control rats 1 to 2 days after transfection. In control and transfected STZ diabetic rats, IGF-1 expression were examined by reverse transcription polymerase chain reaction (RT-PCR), Western blot and histology. The penis beta-galactosidase activity and localization of the STZ diabetic rats were also determined.


RESULTS
One to two days after transfection, the beta-galactosidase was found in the smooth muscle cells of the diabetic rat penis transfected with AdCMV-betagal. One to 2 days after administration of AdCMV-IGF-1, the cavernosal pressure, as determined by the ratio of maximal intracavernous pressure-to-mean arterial pressure (ICP/MAP) and total intracavernous pressure (ICP), was increased in response to cavernous nerve stimulation. Transgene expression was confirmed by RT-PCR, Western blot and histology.


CONCLUSIONS
Gene transfer of IGF-1 significantly increased erectile function in the STZ diabetic rats. These results suggest that in vivo gene transfer of IGF-1 might be a new therapeutic intervention for the treatment of erectile dysfunction (ED) in the STZ diabetic rats.
Pu
Xiao-Yong
XY
Department of Urology, Guangdong Provincial People's Hospital, Guangzhou 510080, China.
Hu
Li-Quan
LQ
Wang
Huai-Peng
HP
Luo
Yao-Xiong
YX
Wang
Xing-Huan
XH
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D007172:Erectile Dysfunction / Q000517:prevention & control*; D015316:Genetic Therapy; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D008297:Male; D010410:Penile Erection / Q000502:physiology*; D010413:Penis / Q000201:enzymology / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D001616:beta-Galactosidase / Q000378:metabolism
D001786:Blood Glucose; D007334:Insulin-Like Growth Factor I; D001616:beta-Galactosidase