Endothelial and neuronal-derived nitric oxide mediated relaxation of corpus cavernosal smooth muscle in a rat, in vitro, model of erectile function

Abstract

We set out to establish a simple, reproducible, rat in vitro model of erectile function and to use this to demonstrate the functional importance of both neuronal-and endothelial-derived nitric oxide within this animal.Two corpora cavernosal smooth muscle strips were harvested from sexually mature male Wistar rats and mounted in an organ bath for measurement of isometric tension. Following contraction with noradrenaline the strips were relaxed by the addition of either acetylcholine or sodium nitroprusside. Electrical ®eld stimulation was performed in the presence of atropine and guanethidine. Relaxation responses were repeated in the presence of methylene blue, L-arginine, L-NNA and haemoglobin AE L-arginine.Methylene blue abolishes the relaxation to acetylcholine and EFS; L-NNA and haemoglobin cause a signi®cant impairment in the relaxation response. L-arginine reverses the effect of haemoglobin.In conclusion, the inhibitory, relaxant stimulus of rat corpora cavernosa is due to both neuronal nitric oxide and endothelial-derived nitric oxide released in response to cholinergic stimulation.

Mechanisms of Penile Erection and Basis for Pharmacological Treatment of Erectile Dysfunction

“…We were surprised to find that isolated corporal tissue from both wild-type and NOS-deleted animals showed similar responses to electrical stimulation (Burnett et al, 1996;Hurt et al, 2006). Functional studies support the occurrence and importance of eNOS in human cavernosal tissue (Andersson and Wagner, 1995;Musicki and Burnett, 2006), and this seems to be the case also in rat (Cartledge et al, 2000b) and mouse (Mizusawa et al, 2001) CC.…”

Vasoactivity, antioxidant and aphrodisiac properties of Caesalpinia benthamiana roots

“…Functional studies support the occurrence and importance of eNOS in cavernous tissue ( Anderson and Wagner, 1995;Cartledge et al, 2000). eNOS expression and eNOS activity increase during erection.…”

Association of nNOS and Rho-kinase with age-associated erectile dysfunction in Sprague-Dawley rats

“…Another study demonstrated that there is ~13% decrease in the gene expression of nNOS in the penises of aged rats (17). In addition, increasing evidence has shown that endothelial and neuronal-derived nitric oxide acts as an important mediator of corpus cavernosal smooth-muscle relaxation and penile erection in rats with ED (18). nNOS was also shown to be involved in mediating initiation as well as maintenance of penile erection via cyclic adenosine monophosphate-dependent phosphorylation (9).…”