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Nitric oxide mediated erectile activity is a testosterone dependent event: a rat erection model
P Zvara1, R Sioufi, H M Schipper
1Lady Davis Institute for Medical Research Department of Urology, Montreal, Quebec, Canada.
International Journal of Impotence Research
|December 1, 1995
Summary
Testosterone directly impacts erectile function by influencing nitric oxide synthase (NOS) in the corpora cavernosa. Lowering testosterone levels reduces erectile response and NOS-positive nerve fibers, which are restored with testosterone replacement.
Area of Science:
- Urology
- Endocrinology
- Neuroscience
Background:
- Androgens have historically been linked to male sexual activity and libido.
- Recent research suggests a connection between sex hormones and nitric oxide synthase (NOS), crucial for erectile function.
Purpose of the Study:
- To investigate the impact of altered testosterone levels on erectile function.
- To determine the role of testosterone in regulating nitric oxide synthase (NOS) within the penile tissue.
Main Methods:
- Erectile response was measured in orchiectomized rats at various time points post-surgery.
- Penile tissues were stained for NOS using NADPH diaphorase technique.
- Erectile function and NOS nerve fiber density were assessed after exogenous testosterone administration in castrated rats.
Main Results:
- Orchiectomy led to a rapid decrease in serum testosterone and a gradual decline in erectile response.
- A time-dependent reduction in NOS-positive nonadrenergic noncholinergic (NANC) nerve fibers was observed post-orchiectomy.
- Testosterone replacement normalized erectile function and restored NOS-positive nerve fiber density.
Conclusions:
- Testosterone or its metabolite plays a direct role in mediating erectile function.
- The effect of testosterone on erection is linked to its influence on nitric oxide synthase (NOS) in the corpora cavernosa.