1.Injectable agents for the induction of Peyronie's disease in model rats: a comparative study.
Guang-Jun DU ; Si-Yan XING ; Ning WU ; Tong WANG ; Yue-Hui JIANG ; Tao SONG ; Bai-Bing YANG ; Yu-Tian DAI
Asian Journal of Andrology 2025;27(1):96-100
Peyronie's disease (PD) is a disorder characterized by fibrous plaque formation in the penile tissue that leads to curvature and complications in advanced stages. In this study, we aimed to compare four injectable induction agents for the establishment of a robust rat model of PD: transforming growth factor-β1 (TGF-β1), fibrin, sodium tetradecyl sulfate (STS) combined with TGF-β1, and polidocanol (POL) combined with TGF-β1. The results showed that injection of TGF-β1 or fibrin into the tunica albuginea induced pathological endpoints without causing penile curvature. The STS + TGF-β1 combination resulted in both histological and morphological alterations, but with a high incidence of localized necrosis that led to animal death. The POL + TGF-β1 combination produced pathological changes and curvature comparable to STS + TGF-β1 and led to fewer complications. In conclusion, fibrin, STS + TGF-β1, and POL + TGF-β1 all induced PD with a certain degree of penile curvature and histological fibrosis in rats. The POL + TGF-β1 combination offered comparatively greater safety and clinical relevance and may have the greatest potential for PD research using model rats.
Animals
;
Male
;
Penile Induration/drug therapy*
;
Rats
;
Transforming Growth Factor beta1/metabolism*
;
Disease Models, Animal
;
Fibrin
;
Penis/drug effects*
;
Polidocanol/administration & dosage*
;
Rats, Sprague-Dawley
;
Polyethylene Glycols/administration & dosage*
;
Injections
2.Exogenous administration of heparin-binding epidermal growth factor-like growth factor improves erectile function in mice with bilateral cavernous nerve injury.
Minh Nhat VO ; Mi-Hye KWON ; Fang-Yuan LIU ; Fitri Rahma FRIDAYANA ; Yan HUANG ; Soon-Sun HONG ; Ju-Hee KANG ; Guo Nan YIN ; Ji-Kan RYU
Asian Journal of Andrology 2025;27(6):697-706
Prostate cancer is the second most common malignancy and the sixth leading cause of cancer-related death in men worldwide. Radical prostatectomy (RP) is the standard treatment for localized prostate cancer, but the procedure often results in postoperative erectile dysfunction (ED). The poor efficacy of phosphodiesterase 5 inhibitors after surgery highlights the need to develop new therapies to enhance cavernous nerve regeneration and improve the erectile function of these patients. In the present study, we aimed to examine the potential of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in preserving erectile function in cavernous nerve injury (CNI) mice. We found that HB-EGF expression was reduced significantly on the 1 st day after CNI in penile tissue. Ex vivo and in vitro studies showed that HB-EGF promotes major pelvic ganglion neurite sprouting and neuro-2a (N2a) cell migration. In vivo studies showed that exogenous HB-EGF treatment significantly restored the erectile function of CNI mice to 86.9% of sham levels. Immunofluorescence staining showed that mural and neuronal cells were preserved by inducing cell proliferation and reducing apoptosis and reactive oxygen species production. Western blot analysis showed that HB-EGF upregulated protein kinase B and extracellular signal-regulated kinase activation and neurotrophic factor expression. Overall, HB-EGF is a major promising therapeutic agent for treating ED in postoperative RP.
Animals
;
Male
;
Heparin-binding EGF-like Growth Factor/therapeutic use*
;
Erectile Dysfunction/etiology*
;
Mice
;
Penis/drug effects*
;
Nerve Regeneration/drug effects*
;
Penile Erection/drug effects*
;
Peripheral Nerve Injuries/drug therapy*
;
Cell Proliferation/drug effects*
;
Apoptosis/drug effects*
;
Cell Movement/drug effects*
;
Prostatectomy/adverse effects*
;
Mice, Inbred C57BL
;
Reactive Oxygen Species/metabolism*
3.Acute dual therapeutic effects of the BKCa channel opener LDD175 on erectile dysfunction and lower urinary tract symptoms in chronic pelvic ischemia: a preliminary study.
Jiwoong YU ; Mee Ree CHAE ; Deok Hyun HAN ; Su Jeong KANG ; Jimin SHIN ; Hyun Hwan SUNG
Asian Journal of Andrology 2025;27(6):714-722
Recent studies have revealed a significant relationship between erectile dysfunction (ED) and lower urinary tract symptoms (LUTS), both of which commonly affect middle-aged and older men. These conditions share underlying causes, particularly endothelial dysfunction, atherosclerosis, and chronic pelvic ischemia (CPI). This study investigated the therapeutic potential of LDD175, a large-conductance Ca 2+ -activated K + channel (BKCa channel) opener, in simultaneously treating both conditions using a CPI animal model of male Sprague Dawley rats. Our study investigated the induction of CPI through surgical endothelial damage combined with a high-cholesterol diet. We assessed erectile and voiding functions by measuring intracavernosal pressure (ICP) and intraurethral pressure (IUP), respectively, after nerve stimulation. We performed histological examinations of vascular changes and western blot analyses of cavernous and prostate tissues to understand the underlying mechanisms. This study evaluated the effectiveness of LDD175 compared to standard treatments, such as sildenafil for ED and tamsulosin for LUTS. Therefore, the CPI model successfully demonstrated ED and LUTS symptoms with decreased ICP and increased IUP. Analysis revealed elevated levels of hypoxia-inducible factor-1α, transforming growth factor-β1 and β2 in cavernous tissue, and increased α1A-adrenoceptor expression in prostate tissue. LDD175 administration showed promising results, with dose-dependent improvements in ICP and IUP, and therapeutic effects comparable to those of established treatments. Our findings suggest a novel therapeutic approach that can simultaneously address ED and LUTS, opening new possibilities for clinical application in the treatment of these interconnected conditions.
Male
;
Animals
;
Erectile Dysfunction/etiology*
;
Rats, Sprague-Dawley
;
Lower Urinary Tract Symptoms/etiology*
;
Ischemia/drug therapy*
;
Rats
;
Tamsulosin
;
Hypoxia-Inducible Factor 1, alpha Subunit/drug effects*
;
Sildenafil Citrate/therapeutic use*
;
Penis/blood supply*
;
Disease Models, Animal
;
Transforming Growth Factor beta1/metabolism*
;
Pelvis/blood supply*
;
Prostate/metabolism*
;
Sulfonamides/therapeutic use*
;
Large-Conductance Calcium-Activated Potassium Channels/agonists*
4.Qiwei No.3 combined with sildenafil inhibits Rho kinase activity and increases AKT/eNOS expressions in the penile cavernosum of rats with diabetic erectile dysfunction.
Wei ZHAO ; Lin LI ; Li ZHANG ; Xiao-Qing ZHAO ; Dong-Xu LI ; Jing XIA
National Journal of Andrology 2024;30(12):1128-1134
OBJECTIVE:
To explore the effects of Qiwei No.3 combined with sildenafil on Rho kinase activity and AKT/eNOS pathways in the penile cavernous tissue of male rats with diabetic erectile dysfunction (DED).
METHODS:
We constructed a model of DED in 24 SD male rats by intraperitoneal injection of streptozotocin solution and injecting apomorphine into the neck after 8 weeks of feeding, equally randomized the model rats into a model control (MC), a sildenafil (S), a low-dose Qiwei No.3 combined with sildenafil (LQ+S) and a high-dose Qiwei No.3 combined with sildenafil (HQ+S) group, and took another 6 normal male rats as blank controls (BC). We treated intragastrically the animals in the BC and MC groups with normal saline, and those in the S, LQ+S and HQ+S groups with sildenafil (5 mg/kg/d), Qiwei No.3 (10 g/kg/d) + sildenafil (5mg/kg/d), and Qiwei No.3 (20g/kg/d) + sildenafil (5mg/kg/d), respectively. After 6 weeks of treatment, we recorded the number of penile erections of all the rats by injecting apomorphine into the neck, and measured the activity of Rho kinase and expressions of p-AKT and eNOS proteins in the corpus cavernosum by Western blot.
RESULTS:
Compared with the blank controls, all the DED model rats showed evidently elevated blood glucose and reduced body weight. The number of penile erections was significantly increased in the S, LQ+S and HQ+S groups in comparison with that in the model controls (P< 0.05), even higher in the HQ+S than in the S group (P< 0.05). The activity of Rho kinase in the penile cavernosum was significantly higher in the MC than in the BC group (P<0.05), but lower in the HQ+S than in the S group (P< 0.05). No statistically significant difference was observed in the expression level of the p-AKT protein in the penile cavernosum among the five groups of rats (P > 0.05). The expression of eNOS was remarkably up-regulated in the BC and HQ+S groups (P< 0.05) compared with that in the MC group, even more significantly in the HQ+S than in the LQ+S and S groups (P< 0.05).
CONCLUSION
The combination of high-dose "Qiwei No. 3" and sildenafil can improve erectile function in DED rats, which may be attributed to its effect of releasing more nitric oxide (NO) by inhibiting the activity of Rho kinase and up-regulating the expression of the e-NOS protein.
Animals
;
Male
;
Sildenafil Citrate
;
Rats
;
rho-Associated Kinases/antagonists & inhibitors*
;
Rats, Sprague-Dawley
;
Penis/drug effects*
;
Erectile Dysfunction/etiology*
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Nitric Oxide Synthase Type III/metabolism*
;
Diabetes Mellitus, Experimental/complications*
;
Drugs, Chinese Herbal/therapeutic use*
5.The effects of single versus combined therapy using LIM-kinase 2 inhibitor and type 5 phosphodiesterase inhibitor on erectile function in a rat model of cavernous nerve injury-induced erectile dysfunction.
Min Chul CHO ; Junghoon LEE ; Juhyun PARK ; Sohee OH ; Ji Sun CHAI ; Hwancheol SON ; Jae-Seung PAICK ; Soo Woong KIM
Asian Journal of Andrology 2019;21(5):493-500
We aimed to determine whether combination of LIM-kinase 2 inhibitor (LIMK2i) and phosphodiesterase type-5 inhibitor (PDE5i) could restore erectile function through suppressing cavernous fibrosis and improving cavernous apoptosis in a rat model of cavernous nerve crush injury (CNCI). Seventy 12-week-old Sprague-Dawley rats were equally distributed into five groups as follows: (1) sham surgery (Group S), (2) CNCI (Group I), (3) CNCI treated with daily intraperitoneal administration of 10.0 mg kg-1 LIMK2i (Group I + L), (4) daily oral administration of 20.0 mg kg-1 udenafil, PDE5i (Group I + U), and (5) combined administration of 10.0 mg kg-1 LIMK2i and 20.0 mg kg-1 udenafil (Group I + L + U). Rats in Groups I + L, I + U, and I + L + U were treated with respective regimens for 2 weeks after CNCI. At 2 weeks after surgery, erectile response was assessed using electrostimulation. Penile tissues were processed for histological studies and western blot. Group I showed lower intracavernous pressure (ICP)/mean arterial pressure (MAP), lower area under the curve (AUC)/MAP, decreased immunohistochemical staining for alpha-smooth muscle (SM) actin, higher apoptotic index, lower SM/collagen ratio, increased phospho-LIMK2-positive fibroblasts, decreased protein kinase B/endothelial nitric oxide synthase (Akt/eNOS) phosphorylation, increased LIMK2/cofilin phosphorylation, and increased protein expression of fibronectin, compared to Group S. In all three treatment groups, erectile responses, protein expression of fibronectin, and SM/collagen ratio were improved. Group I + L + U showed greater improvement in erectile response than Group I + L. SM content and apoptotic index in Groups I + U and I + L + U were improved compared to those in Group I. However, Group I + L did not show a significant improvement in SM content or apoptotic index. The number of phospho-LIMK2-positive fibroblasts was normalized in Groups I + L and I + L + U, but not in Group I + U. Akt/eNOS phosphorylation was improved in Groups I + U and I + L + U, but not in Group I + L. LIMK2/cofilin phosphorylation was improved in Groups I + L and I + L + U, but not in Group I + U. Our data indicate that combined treatment of LIMK2i and PDE5i immediate after CN injury could improve erectile function by improving cavernous apoptosis or eNOS phosphorylation and suppressing cavernous fibrosis. Rectification of Akt/eNOS and LIMK2/cofilin pathways appears to be involved in their improvement.
Animals
;
Apoptosis/drug effects*
;
Arterial Pressure
;
Electric Stimulation
;
Erectile Dysfunction/pathology*
;
Lim Kinases/antagonists & inhibitors*
;
Male
;
Nerve Crush
;
Nitric Oxide Synthase Type III/metabolism*
;
Penis/pathology*
;
Peripheral Nerve Injuries/pathology*
;
Phosphodiesterase 5 Inhibitors/therapeutic use*
;
Phosphorylation
;
Pyrimidines/therapeutic use*
;
Rats
;
Rats, Sprague-Dawley
;
Sulfonamides/therapeutic use*
6.Losartan improves erectile function through suppression of corporal apoptosis and oxidative stress in rats with cavernous nerve injury.
Yi WANG ; Xiang-Hu MENG ; Qi-Jie ZHANG ; Ya-Min WANG ; Chen CHEN ; Yi-Chun WANG ; Xiang ZHOU ; Cheng-Jian JI ; Ning-Hong SONG
Asian Journal of Andrology 2019;21(5):452-459
This study aimed to investigate the functional and morphological changes in the corpus cavernosum after cavernous nerve (CN) injury or neurectomy and then reveal whether treatment with the angiotensin II Type 1 receptor antagonist losartan would improve erectile function as well as its potential mechanisms. A total of 48 10-week-old Sprague-Dawley male rats, weighing 300-350 g, were randomly divided into the following four groups (n = 12 per group): sham operation (Sham) group, bilateral cavernous nerve injury (BCNI) group, losartan-treated BCNI (BCNI + Losartan) group, and bilateral cavernous neurectomy (Neurectomy) group. Losartan was administered once daily by oral gavage at a dose of 30 mg kg-1 day-1 for 4 weeks starting on the day of surgery. The BCNI and the Neurectomy groups exhibited decreases in erectile response and increases in apoptosis and oxidative stress, compared with the Sham group. Treatment with losartan could have a modest effect on erectile function and significantly prevent corporal apoptosis and oxidative stress. The phospho-B-cell lymphoma 2 (Bcl-2)-associated death promoter (p-Bad)/Bad and phospho-the protein kinase B (p-AKT)/AKT ratios were substantially lower, while the Bcl-2-associated X protein (Bax)/Bcl-2 ratio, nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap-1), transforming growth factor-β 1 (TGF-β 1) and heme oxygenase-1 (HO-1) levels, and caspase-3 activity were higher in the BCNI and Neurectomy groups than in the Sham group. After 4 weeks of daily administration with losartan, these expression levels were remarkably attenuated compared with the BCNI group. Taken together, our results suggested that early administration of losartan after CN injury could slightly improve erectile function and significantly reduce corporal apoptosis and oxidative stress by inhibiting the Akt/Bad/Bax/caspase-3 and Nrf2/Keap-1 pathways.
Angiotensin II Type 1 Receptor Blockers/pharmacology*
;
Animals
;
Apoptosis/drug effects*
;
Denervation
;
Disease Models, Animal
;
Erectile Dysfunction/metabolism*
;
Losartan/pharmacology*
;
Male
;
Oxidative Stress/drug effects*
;
Penile Erection/drug effects*
;
Penis/metabolism*
;
Rats
;
Rats, Sprague-Dawley
7.Anti-cicatricial and anti-restenosis effect of verapamil on anterior urethral stricture: A randomized controlled clinical trial.
Ruizhi XUE ; Jintang LIAO ; Ting TIAN ; Zhengyan TANG
Journal of Central South University(Medical Sciences) 2018;43(8):843-851
To evaluate the anti-cicatricial and anti-restenosis effect of verapamil on anterior urethral stricture.
Methods: A total of 32 patients received anterior urethral stricture were enrolled in this study. They were divided into 4 blocks according to the duration of previous urethral operations and dilations. Every block was further randomly divided into an experimental group and a control group. Experimental groups received 2 mL injection of verapamil around the anastomosis site of urethra before and after the surgery (2, 4, 6, 8, and 10 weeks after the surgery), while the control groups only received the anastomosis surgery. After surgery, maximal urinary flow rate (Qmax) was examined for all patients once the catheter was removed. In addition, they were also conducted palpation of urethral scar range. The sum of long transverse diameters of urethral scar was measured, and the narrowest urethral inner diameter was examined. The Qmax was rechecked and the urethral scar range was assessed by penis color Doppler elastography after 12 weeks of surgery. The above 4 indexes were used to evaluate the inhibitory effect of verapamil on urethral scar.
Results: The length of palpated urethral scar in the Block 1 to 4 of the experimental groups was (22.75±1.03), (21.25±0.25), (20.75±1.03), and (20.0±0.58) mm, respectively; and those in the control groups (26.00±0.82), (24.5±1.04), (25.75±1.65), and (28.25±1.75) mm, respectively. The Qmax rates in the Block 1 to 4 of the experimental groups were (11.85±0.77), (11.33±0.81), (10.23±0.26), and (10.35±0.17) mL/s, respectively; and those in the control groups were (10.85±0.39), (10.50±0.76), (10.53±1.00), (12.60±0.39) mL/s, respectively. The Qmax rates in the Block 1 to 4 of the experimental groups were (11.73±0.87), (10.65±0.25), (10.23±0.19), and (10.35±0.29) mL/s, respectively; and those in the control groups were (8.05±0.28), (7.73±0.68), (7.53±0.92), and (9.60±0.32) mL/s, respectively. The narrowest diameters of urethral in the Block 1 to 4 of the experimental groups were (9.00±0.58), (7.50±2.89), (7.00±0.10), and (7.00±0.41) mm, respectively; and those in the control groups were (5.50±0.29), (5.00±0.41), (4.75±0.48), and (6.75±0.48) mm, respectively. The ultrasound strain ratio in the Block 1 to 4 of the experimental groups were 6.10±0.22, 6.10±0.17, 5.10±0.16, and 6.90±0.19, respectively; and those in the control groups were 8.00±0.25, 10.60±0.29, 11.30±0.16, and 8.90±0.33, respectively. Compared with the control groups, the experimental groups displayed smaller urethral scar range, less severe scarring, improved Qmax rates and wider inner diameters (all P<0.05).
Conclusion: Urethral regional injection of verapamil intraoperatively or postoperatively can prevent overgrowth of urethral scar tissues after the transperineal anastomosis surgery, and reduce the tendency of postoperative restenosis of anterior urethral stricture.
Anastomosis, Surgical
;
adverse effects
;
Cicatrix
;
diagnostic imaging
;
drug therapy
;
prevention & control
;
Dilatation
;
adverse effects
;
Humans
;
Male
;
Penis
;
diagnostic imaging
;
Postoperative Complications
;
diagnostic imaging
;
drug therapy
;
prevention & control
;
Secondary Prevention
;
Ultrasonography
;
Urethra
;
diagnostic imaging
;
surgery
;
Urethral Stricture
;
prevention & control
;
surgery
;
Urination
;
Urological Agents
;
therapeutic use
;
Verapamil
;
therapeutic use
8.Aldosterone induces inflammatory cytokines in penile corpus cavernosum by activating the NF-κB pathway.
Fei WU ; Zu-Quan XIONG ; Shan-Hua MAO ; Ji-Meng HU ; Jian-Qing WANG ; Hao-Wen JIANG ; Qiang DING
Asian Journal of Andrology 2018;20(1):24-29
Emerging evidence indicates that aldosterone and mineralocorticoid receptors (MRs) are associated with the pathogenesis of erectile dysfunction. However, the molecular mechanisms remain largely unknown. In this study, freshly isolated penile corpus cavernosum tissue from rats was treated with aldosterone, with or without MRs inhibitors. Nuclear factor (NF)-kappa B (NF-κB) activity was evaluated by real-time quantitative PCR, luciferase assay, and immunoblot. The results demonstrated that mRNA levels of the NF-κB target genes, including inhibitor of NF-κB alpha (IκB-α), NF-κB1, tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6), were higher after aldosterone treatment. Accordingly, phosphorylation of p65/RelA, IκB-α, and inhibitor of NF-κB kinase-β was markedly increased by aldosterone. Furthermore, knockdown of MRs prevented activation of the NF-κB canonical pathway by aldosterone. Consistent with this finding, ectopic overexpression of MRs enhanced the transcriptional activation of NF-κB by aldosterone. More importantly, the MRs antagonist, spironolactone blocked aldosterone-mediated activation of the canonical NF-κB pathway. In conclusion, aldosterone has an inflammatory effect in the corpus cavernosum penis, inducing NF-κB activation via an MRs-dependent pathway, which may be prevented by selective MRs antagonists. These data reveal the possible role of aldosterone in erectile dysfunction as well as its potential as a novel pharmacologic target for treatment.
Aldosterone/pharmacology*
;
Animals
;
Cytokines/biosynthesis*
;
Gene Knockdown Techniques
;
I-kappa B Kinase/antagonists & inhibitors*
;
Interleukin-6/genetics*
;
Male
;
Mineralocorticoid Receptor Antagonists/pharmacology*
;
NF-kappa B/genetics*
;
Penis/metabolism*
;
Protein Serine-Threonine Kinases/antagonists & inhibitors*
;
RNA, Messenger/biosynthesis*
;
Rats
;
Rats, Inbred WKY
;
Receptors, Mineralocorticoid/genetics*
;
Signal Transduction/drug effects*
;
Spironolactone/pharmacology*
;
Transcriptional Activation
;
Tumor Necrosis Factor-alpha/biosynthesis*
;
NF-kappaB-Inducing Kinase
9.Lipoxin A4 improves erectile dysfunction in rats with type I diabetes by inhibiting oxidative stress and corporal fibrosis.
Kai CUI ; Zhe TANG ; Chuan-Chang LI ; Tao WANG ; Ke RAO ; Shao-Gang WANG ; Ji-Hong LIU ; Zhong CHEN
Asian Journal of Andrology 2018;20(2):166-172
Previous studies have shown that oxidative stress and corporal fibrosis in penile tissues of rats were key pathological factors of erectile dysfunction induced by diabetic mellitus (DMED). Lipoxin A4 (LXA4) was reported to inhibit oxidative stress and fibrosis diseases, while whether it could exert a protective role on erectile function was not clear. Type I diabetic mellitus (DM) was induced in thirty male 10-week-old Sprague-Dawley rats using streptozotocin. Ten weeks later, twenty-two rats with DMED confirmed by an apomorphine test were divided into two groups: the DMED group (n = 11) and the DMED + LXA4 group (n = 11; LXA4 injection daily for 4 weeks). In addition, another ten age-matched rats formed the Control group. We found that erectile function was significantly impaired in the DMED group compared with the Control group, but was improved in the DMED + LXA4 group. Similarly, the over-activated oxidative stress and impaired endothelial function in the DMED group were both improved in the DMED + LXA4 group. Moreover, the DMED group showed serious corporal fibrosis, which was also inhibited by the treatment of LXA4 in the DMED + LXA4 group. Taken together, LXA4 could exert an inhibition role on oxidative stress and fibrosis to improve DMED effectively.
Actins/metabolism*
;
Animals
;
Anti-Inflammatory Agents, Non-Steroidal/pharmacology*
;
Diabetes Mellitus, Experimental/physiopathology*
;
Diabetes Mellitus, Type 1/physiopathology*
;
Erectile Dysfunction/physiopathology*
;
Fibrosis
;
Lipoxins/pharmacology*
;
Male
;
Nitric Oxide/metabolism*
;
Nitric Oxide Synthase Type III/metabolism*
;
Oxidative Stress/drug effects*
;
Penile Erection/drug effects*
;
Penis/pathology*
;
Rats
;
Rats, Sprague-Dawley
10.Calpain inhibition improves erectile function in diabetic mice via upregulating endothelial nitric oxide synthase expression and reducing apoptosis.
Hao LI ; Li-Ping CHEN ; Tao WANG ; Shao-Gang WANG ; Ji-Hong LIU
Asian Journal of Andrology 2018;20(4):342-348
Calpain activation contributes to hyperglycemia-induced endothelial dysfunction and apoptosis. This study was designed to investigate the role of calpain inhibition in improving diabetic erectile dysfunction (ED) in mice. Thirty-eight-week-old male C57BL/6J mice were divided into three groups: (1) nondiabetic control group, (2) diabetic mice + vehicle group, and (3) diabetic mice + MDL28170 (an inhibitor of calpain) group. Type 1 diabetes was induced by intraperitoneal injection of streptozotocin at 60 mg kg-1 body weight for 5 consecutive days. Thirteen weeks later, diabetic mice were treated with MDL28170 or vehicle for 4 weeks. The erectile function was assessed by electrical stimulation of the cavernous nerve. Penile tissues were collected for measurement of calpain activity and the endothelial nitric oxide synthase (eNOS)-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway. Terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL) staining was used to evaluate apoptosis. Caspase-3 expression and activity were also measured to determine apoptosis. Our results showed that erectile function was enhanced by MDL28170 treatment in diabetic mice compared with the vehicle diabetic group. No differences in calpain-1 and calpain-2 expressions were observed among the three groups. However, calpain activity was increased in the diabetic group and reduced by MDL28170. The eNOS-NO-cGMP pathway was upregulated by MDL28170 treatment in diabetic mice. Additionally, MDL28170 could attenuate apoptosis and increase the endothelium and smooth muscle levels in corpus cavernosum. Inhibition of calpain could improve erectile function, probably by upregulating the eNOS-NO-cGMP pathway and reducing apoptosis.
Animals
;
Apoptosis/drug effects*
;
Calpain/antagonists & inhibitors*
;
Cyclic GMP/biosynthesis*
;
Diabetes Complications/drug therapy*
;
Diabetes Mellitus, Experimental/complications*
;
Dipeptides/therapeutic use*
;
Endothelium/metabolism*
;
Enzyme Inhibitors/therapeutic use*
;
Erectile Dysfunction/etiology*
;
In Situ Nick-End Labeling
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Muscle, Smooth/metabolism*
;
Nitric Oxide Synthase Type III/biosynthesis*
;
Penis/enzymology*
;
Up-Regulation

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