Effects of Intracavernosal IGF-1 Gene Delivery on Erectile Function in the Aging Rat.
- Author:
Kwangsung PARK
1
;
Taek Won KANG
;
Min Kyung KIM
;
Kyung Keun KIM
;
Kyuyoun AHN
;
Soo Bang RYU
Author Information
1. Departments of Urology, Chonnam National University Medical School, Gwangju, Korea. kpark@chonnam.ac.kr
- Publication Type:Original Article
- Keywords:
IGF-1;
Gene;
Delivery;
Erectile dysfunction
- MeSH:
Aging*;
Animals;
Arterial Pressure;
Blotting, Western;
DNA, Complementary;
Erectile Dysfunction;
Hemodynamics;
Humans;
Insulin;
Insulin-Like Growth Factor I*;
Male;
Muscle, Smooth;
Myocytes, Smooth Muscle;
Plasmids;
Rats*;
Rats, Inbred F344;
Rats, Sprague-Dawley;
Reverse Transcriptase Polymerase Chain Reaction;
RNA, Messenger;
Transfection
- From:Korean Journal of Urology
2005;46(4):406-413
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: Insulin like Growth Factor-1 (IGF-1) promotes the proliferation and migration of penile cavernous smooth muscle cells in rats. The goal of this study was to investigate the effects of an intracavernosal injection of the IGF-1 gene on the erectile function in the aging rat. MATERIALS AND METHODS: Corpus cavernosum smooth muscle cells (CCSMCs) were primarily cultured from Sprague-Dawley rats (16 wks). IGF-1 cDNA was subcloned into pcDNA3.1, and this expression plasmid transfected into CCSMCs. Two, three and four days after transfection, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot analyses were carried out to quantify the transfection efficiency. In an in vivo study, male F344 rats (n=28) were divided into 2 groups; the young (5 months; n=7) and the old (20-21 months; n=21) groups. The old group was further divided into control (n=7) and treatment groups (n=14). The treatment group was given a single intracavernosal injection of DNA-liposome complex (pcDNA alone and pcDNA/IGF-1; 2mug or 4mug in 7 animals each). After 4 weeks of treatment, the erectile function and corpus cavernosal histology were evaluated by hemodynamic study and histomorphometric analysis, respectively. RESULTS: When the CCSMCs were transfected with IGF-1, the IGF-1 mRNA and protein were overexpressed compared to the control. After 4 weeks of treatment, the ratio of the peak intracavernosal pressure to systemic arterial pressure increased in the treatment group (66.3+/- 4.3% with 2mug, 65.4+/- 10.2% with 4mug), but without statistical significance (p>0.05) compared to the control group (55.5+/- 16.7%). The percentage of cavernosal smooth muscle also slightly increased in the treatment group (14.1+/-1.7% with 2mug), but without statistical significance (p>0.05) compared to the control group (13.2+/-1.2%). CONCLUSIONS: IGF-1 mRNA and IGF-1 protein were overexpressed in the rat corpus cavernosum smooth muscle cells due to IGF-1 gene delivery. However, lipid-mediated intracavernosal gene delivery of IGF-1 did not significantly improve the erectile function in the aging rat.
