Recent studies in the field of erection physiology have acknowledged that long-standing defective constitutive nitric oxide (NO) signaling in the penis may contribute significantly toward the pathophysiology of diverse erectile disorders including recurrent ischemic priapism, vasculogenic erectile dysfunction (ED), and penile fibrosis. The gaseous chemical NO is not just a physiologic mediator of penile erection, but it is also a homeostatic regulator involved in the steady state vascular biology of the penis. Accordingly, new directions in this research field involve investigating further this particular role of the chemical in the pathophysiology of erectile disorders. The primary hypothesis of this proposal is that """"""""NO imbalance"""""""" occurs in the penile vasculature in association with various erectile disorders providing a molecular basis for their development. We have focused our investigation on the pathophysiology of recurrent priapism, an erectile disorder of repetitively occurring non-willful, excessive, and painful penile erection, which frequently results in permanent erectile tissue damage, erectile dysfunction, and psychological distress. We submit that specific molecular abnormalities are associated with this disorder, including 1) defective endothelial NO production sources;2) altered circulating (hemoglobin and plasma) NO delivery;and 3) increased oxidative stress leading to NO degradation.
Specific aims for the proposal are: 1) to determine whether NO signaling of vascular homeostasis is defective in the penis in association with recurrent priapism;2) to investigate molecular mechanisms which contribute toward NO imbalance in the penis in association with recurrent priapism;and 3) to evaluate the effects of restoring NO bioactivity to the penis under conditions of recurrent priapism. Our proposed research work plan includes the use of experimental mouse animal models in combination with molecular and physiologic studies relevant to the NO-based signal transduction pathway in the penis and oxidative/nitrosative stress mechanisms. It is anticipated that findings produced by this study will provide a clearer understanding of the cellular and molecular mechanisms underlying recurrent ischemic priapism and provide a rational basis for its treatment. Recent studies in the field of erection physiology have acknowledged that long-standing defective constitutive nitric oxide (NO) signaling in the penis may contribute significantly toward the pathophysiology of diverse erectile disorders including recurrent ischemic priapism, vasculogenic erectile dysfunction (ED), and penile fibrosis. The primary hypothesis of this proposal is that """"""""NO imbalance"""""""" occurs in the penile vasculature in association with various erectile disorders providing a molecular basis for their development. We submit that specific molecular abnormalities are associated with recurrent priapism including 1) defective endothelial NO production sources;2) altered circulating (hemoglobin and plasma) NO delivery;and 3) increased oxidative stress leading to NO degradation. It is anticipated that findings produced by this study will provide a clearer understanding of the cellular and molecular mechanisms underlying this disorder and provide a rational basis for its treatment.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK067223-05
Application #
7577570
Study Section
Special Emphasis Panel (ZRG1-RUS-B (11))
Program Officer
Rankin, Tracy L
Project Start
2004-04-01
Project End
2012-02-28
Budget Start
2009-03-01
Budget End
2010-02-28
Support Year
5
Fiscal Year
2009
Total Cost
$348,500
Indirect Cost
Name
Johns Hopkins University
Department
Urology
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
La Favor, Justin D; Fu, Zongming; Venkatraman, Vidya et al. (2018) Molecular Profile of Priapism Associated with Low Nitric Oxide Bioavailability. J Proteome Res 17:1031-1040
Musicki, Biljana; Bhunia, Anil K; Karakus, Serkan et al. (2018) S-nitrosylation of NOS pathway mediators in the penis contributes to cavernous nerve injury-induced erectile dysfunction. Int J Impot Res 30:108-116
Musicki, B; Burnett, A L (2017) Constitutive NOS uncoupling and NADPH oxidase upregulation in the penis of type 2 diabetic men with erectile dysfunction. Andrology 5:294-298
Matsui, Hotaka; Musicki, Biljana; Sopko, Nikolai A et al. (2017) Early-stage Type 2 Diabetes Mellitus Impairs Erectile Function and Neurite Outgrowth From the Major Pelvic Ganglion and Downregulates the Gene Expression of Neurotrophic Factors. Urology 99:287.e1-287.e7
Karakus, Serkan; Musicki, Biljana; La Favor, Justin D et al. (2017) cAMP-dependent post-translational modification of neuronal nitric oxide synthase neuroprotects penile erection in rats. BJU Int 120:861-872
Akakpo, William; Musicki, Biljana; Burnett, Arthur L (2017) cAMP-dependent regulation of RhoA/Rho-kinase attenuates detrusor overactivity in a novel mouse experimental model. BJU Int 120:143-151
Musicki, B; Hannan, J L; Lagoda, G et al. (2016) Mechanistic link between erectile dysfunction and systemic endothelial dysfunction in type 2 diabetic rats. Andrology 4:977-83
Musicki, Biljana; Lagoda, Gwen; Goetz, Tabitha et al. (2016) Transnitrosylation: A Factor in Nitric Oxide-Mediated Penile Erection. J Sex Med 13:808-814
Silva, Fábio H; Karakus, Serkan; Musicki, Biljana et al. (2016) Beneficial Effect of the Nitric Oxide Donor Compound 3-(1,3-Dioxoisoindolin-2-yl)Benzyl Nitrate on Dysregulated Phosphodiesterase 5, NADPH Oxidase, and Nitrosative Stress in the Sickle Cell Mouse Penis: Implication for Priapism Treatment. J Pharmacol Exp Ther 359:230-237
Burnett, Arthur L; Sezen, Sena F; Hoke, Ahmet et al. (2015) GGF2 is neuroprotective in a rat model of cavernous nerve injury-induced erectile dysfunction. J Sex Med 12:897-905

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