Abstract | INTRODUCTION: AIM: We hypothesized that inhibition of ERK by ERK inhibitor PD98059 decreases AA and thus improves cavernosal relaxation in streptozotocin (STZ)-diabetic mice. METHODS: The AA, ERK, eNOS, and arginase I and II expressions were examined through Western blot, and functional response of cavernosal tissue were determined. Control and diabetic cavernosal tissues were pretreated with PD98059 (10(-5) M) and arginase inhibitor ((S)-(2-boronoethyl)- L-cysteine hydrochloride, [BEC]10(-4) M]). MAIN OUTCOME MEASURES: Diabetes increased AA significantly (twofold) over control mice and this effect was blocked by acute treatment with PD98059. Cavernosal strips from diabetic mice exhibited decreased relaxation (STZ-diabetic vs. control, respectively) to both the endothelium-dependent agonist acetylcholine (38.0 ± 5% vs. 82.5 ± 7%) and nitrergic stimulation (27 ± 2% vs. 76 ± 6%) by electrical field stimulation (EFS, 1-32 Hz). However, this impairment in cavernosal relaxation from diabetic mice was attenuated by treatment with PD98059 in nitrergic (27 ± 2% vs. 60 ± 4%) and endothelium-dependent relaxation responses (38.0 ± 5% vs. 67.5 ± 6%). Acute treatment with the arginase inhibitor BEC (10(-4) M) also improves EFS-induced relaxation in diabetic mice (31 ± 3% vs. 49 ± 2%). Moreover, vascular expression of activated ERK was increased in diabetic over control mice. CONCLUSION: These data suggest that ERK inhibition prevents elevation of penile AA and protects against ED caused by diabetes.
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Authors | Kenia P Nunes, Haroldo A Toque, Ruth B Caldwell, R William Caldwell, R Clinton Webb |
Journal | The journal of sexual medicine
(J Sex Med)
Vol. 8
Issue 12
Pg. 3335-44
(Dec 2011)
ISSN: 1743-6109 [Electronic] Netherlands |
PMID | 21995824
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Copyright | © 2011 International Society for Sexual Medicine. |
Chemical References |
- Flavonoids
- NOS3 protein, human
- Nitric Oxide Synthase Type III
- Extracellular Signal-Regulated MAP Kinases
- Arginase
- 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one
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Topics |
- Analysis of Variance
- Animals
- Arginase
(biosynthesis, drug effects, metabolism)
- Diabetes Mellitus, Experimental
- Disease Models, Animal
- Endothelium, Vascular
(drug effects)
- Extracellular Signal-Regulated MAP Kinases
(antagonists & inhibitors, drug effects)
- Flavonoids
(therapeutic use)
- Impotence, Vasculogenic
(drug therapy)
- Male
- Mice
- Nitric Oxide Synthase Type III
(metabolism)
- Penile Erection
(drug effects)
- Penis
(blood supply, drug effects)
- Signal Transduction
(drug effects)
- Vasodilation
(drug effects)
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