Erectile dysfunction in diabetes is due to defect in brain
March 15, 2007

A new study shed additional light on how erectile dysfunction (ED) interacts with diabetes. The study is an additional step in detection the association between the two disorder, and may lead to better efficiency in erectile dysfunction treatments

Sexual dysfunction is a well-recognized outcome of diabetes mellitus in men. Erectile dysfunction and the loss of seminal emission have all been described by such patients. This study examines induce penile erection, yawning and stretch in diabetic rats. Male Sprague-Dawley rats treated with streptozotocin (STZ) to persuade diabetes were used as they put on display sexual and behavioral symptoms similar to those found in diabetic men with erectile dysfunction.

The researchers focused on the paraventricular nucleus (PVN) of the hypothalamus, situated in the brain, an addition center between the central and peripheral nervous systems. The site is implicated in numerous functions, including erectile function and sexual behavior, and is a primary site within the forebrain that has been implicated in penile erection. The investigators also examined central nitric oxide which plays an significant role in the neurotransmission of normal penile erection.

Penile erection is a behavioral reaction that occurs in answer to the administration of N-methyl-D-aspartic acid within the PVN. At the same time, self-consciousness of NO synthase with NG-monomethly-L-argining prevents NMDA-induced erection. The researchers hypothesized that the dull NMDA mediated response in diabetes reflects an impaired NO instrument within the PVN. The involvement of an NO mechanism in the NMDA mediated behavioral response was also explored.

Four experiments were conducted. Experiment one observe the effect of L-NMMA on NMDA mediated behavioral responses in normal rats; experiment two measured behavioral responses to NMDA or sodium nitroprusside (SNP), an NO donor in both control and diabetic rats; the third experiment observed the effect of diabetes on nNOS protein in the PVN; the fourth experiment measured NMDA mediated behavioral responses in diabetic rats after restoring the nNOS protein in the PVN using viral gene transfer.

So the researchers finish off saying that erectile dysfunction in diabetes is due to a discriminating imperfection in the NO mechanisms within the PVN. This defect is a loss in the synthetic enzyme for the production of NO within the neurons of the PVN. Restoring this synthetic enzyme may have a significant therapeutic value for diabetic patients with erectile dysfunction.

Source:
http://www.eurekalert.org/pub_releases