Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-7-22
pubmed:abstractText
Prior studies from this laboratory, using untreated castrated (CASTRATE) rats and testosterone-treated castrated (TESTO) rats, have shown that the magnitude of the intracavernosal pressure increase during erection is androgen dependent. Studies from this and other laboratories have also presented evidence suggesting that penile erection is mediated principally by nitric oxide (NO). The present report was designed to confirm that androgens maintain the availability of cavernosal NO and to determine if this androgenic action is exerted at the genomic level modulating the expression of the neuronal form of the nitric oxide synthase gene (nNOS). The results showed that administration of supplemental L-arginine failed to augment the erectile response in either group, suggesting that substrate availability is not a cause of the reduced response in CASTRATE animals. Inhibition of NO synthesis with a nitro-arginine competitive inhibitor of nitric oxide synthase enzyme protein (NOS) resulted in strong inhibition of erection in both TESTO and CASTRATE rats. When given in conjunction with ganglionic stimulation to induce erection, the NO releasing drug, sodium nitro-prusside (SNP), increased intracavernosal pressure in CASTRATE rats but not in TESTO rats, suggesting a deficiency of the available NO in CASTRATE-animals. Finally, reverse transcription-polymerase chain reaction (RT-PCR) demonstrated that mRNA levels for the enzyme nNOS in the penis were greater in TESTO animals than in CASTRATE rats. These results support the hypothesis that androgens mediate the erectile response in the rat penis by stimulating the expression of the neuronal isoform of nitric oxide synthase, thus maintaining an adequate supply of NO.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0196-3635
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
110-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9154504-Analysis of Variance, pubmed-meshheading:9154504-Animals, pubmed-meshheading:9154504-Arginine, pubmed-meshheading:9154504-Electric Stimulation, pubmed-meshheading:9154504-Gene Expression Regulation, Enzymologic, pubmed-meshheading:9154504-Male, pubmed-meshheading:9154504-Neurons, pubmed-meshheading:9154504-Nitric Oxide, pubmed-meshheading:9154504-Nitric Oxide Synthase, pubmed-meshheading:9154504-Nitroarginine, pubmed-meshheading:9154504-Nitroprusside, pubmed-meshheading:9154504-Orchiectomy, pubmed-meshheading:9154504-Penile Erection, pubmed-meshheading:9154504-Penis, pubmed-meshheading:9154504-Polymerase Chain Reaction, pubmed-meshheading:9154504-RNA, Messenger, pubmed-meshheading:9154504-Rats, pubmed-meshheading:9154504-Testosterone, pubmed-meshheading:9154504-Transcription, Genetic
pubmed:articleTitle
Androgenic regulation of NO availability in rat penile erection.
pubmed:affiliation
Department of Physiology and Endocrinology, Medical College of Georgia, Augusta 30912-3000, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't