Linked Life Data

16396994

Source:http://linkedlifedata.com/resource/pubmed/id/16396994

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-3-1
pubmed:abstractText
Epidemiologic studies have shown that aging accounts significantly for the prevalence of erectile dysfunction (ED). The pathophysiology of ED during aging and its underlying molecular mechanisms are largely unknown. We hypothesized that increased RhoA/Rho-kinase signaling is a major factor in the pathogenesis of age-associated ED and the mechanism involves increased penile smooth muscle contractility through inhibition of myosin light chain phosphatase. Male Fischer 344 young (4 month old) and aged (20-22 month old) rats underwent erectile function testing in vivo by measuring intracavernosal pressure (ICP) and mean arterial blood pressure (MAP) upon electrical stimulation of the cavernous nerve. The data demonstrated that erectile function was significantly lower in aged rats than that in young rats at all voltages tested (P<0.05). Western blot analysis results showed that there were no significant changes in protein expressions of RhoA, Rho-kinase-alpha and -beta isoforms, and myosin light chain phosphatase target subunit (MYPT1); however, membrane-bound RhoA and phosphorylated MYPT1 were increased in aged rat penes by 95 +/- 15 and 56 +/- 8% (P<0.05), respectively, indicating enhanced RhoA and Rho-kinase activity. Inhibition of Rho-kinase with Y27632 maximally increased ICP/MAP to 0.72 +/- 0.05 in aged rats vs. 0.47 +/- 0.06 in young rats (P<0.05). Gene transfer of adeno-associated virus (AAV) encoding dominant negative RhoA (T19NRhoA) to penes of aged and young rats for 7 days markedly improved erectile function in aged rats when compared with that in young rats (P<0.05). These observations were also supported by Rho-kinase activity assay results showing that basal Rho-kinase activity in aged rat penes receiving AAV vehicle treatment was twofold greater than that in young rat penes receiving AAV vehicle treatment, while it was reduced to a level similar to that in young rat penes after gene therapy of T19NRhoA (P<0.05). Taken together, these data suggest that impaired erectile function during the aging process involves increased RhoA/Rho-kinase signaling, and this pathway may be exploited for the treatment of age-associated ED.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1530-6860
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
536-8
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:16396994-Aging, pubmed-meshheading:16396994-Amides, pubmed-meshheading:16396994-Amino Acid Substitution, pubmed-meshheading:16396994-Animals, pubmed-meshheading:16396994-Dependovirus, pubmed-meshheading:16396994-Erectile Dysfunction, pubmed-meshheading:16396994-Gene Therapy, pubmed-meshheading:16396994-Genetic Vectors, pubmed-meshheading:16396994-Intracellular Signaling Peptides and Proteins, pubmed-meshheading:16396994-Isoenzymes, pubmed-meshheading:16396994-Male, pubmed-meshheading:16396994-Muscle, Smooth, Vascular, pubmed-meshheading:16396994-Muscle Contraction, pubmed-meshheading:16396994-Mutation, Missense, pubmed-meshheading:16396994-Myosin-Light-Chain Phosphatase, pubmed-meshheading:16396994-Penis, pubmed-meshheading:16396994-Protein-Serine-Threonine Kinases, pubmed-meshheading:16396994-Pyridines, pubmed-meshheading:16396994-Rats, pubmed-meshheading:16396994-Rats, Inbred F344, pubmed-meshheading:16396994-Recombinant Fusion Proteins, pubmed-meshheading:16396994-Vasodilation, pubmed-meshheading:16396994-rho-Associated Kinases, pubmed-meshheading:16396994-rhoA GTP-Binding Protein
pubmed:year
2006
pubmed:articleTitle
Elevated RhoA/Rho-kinase activity in the aged rat penis: mechanism for age-associated erectile dysfunction.
pubmed:affiliation
Department of Urology, Johns Hopkins University, Baltimore, Maryland 21287, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural