BACKGROUNDWhile the abnormal appearance of the concealed penis has been well recognized, the effect of buried penis on the structure and function of corpus cavernosum has not been well studied. To explore this issue, we established a rat model and evaluated the effect of buried penis on cavernosum weight, contents and ultrastructure of tissue, and nitric oxide synthase (NOS) activity.

METHODSTwo hundred and ten rats were randomly divided into 3 equal cohorts for 2, 4 and 6 months study (groups A, B and C). Each group was randomly divided into buried group (n = 40), control group (n = 15), and normal group (n = 15), respectively. Intra-purse-string suture of the root of the penis was used to establish the model. Macroscopic development was judged by measuring the weight of the corpus cavernosum. Masson's trichrome staining was performed for observing microstructure while a transmission electron microscope was used for observing ultrastructure. The NOS activity was detected by a NOS activity assay kit.

RESULTSBuried penis had no significant influence on the appearance and weight of the corpus cavernosum. Buried penis resulted in decreased smooth muscle content (P > 0.05 in group A, and P < 0.05 in groups B and C) and increased fibrous connective tissue content (P > 0.05 in groups A and B, and P < 0.05 in group C) compared with the normal and control groups. Ultrastructural abnormalities of corpus cavernosum were observed in the 6-month buried group. Moreover, there was decrease of NOS activity in groups B and C (P < 0.05 in group B and P < 0.01 in group C) when compared with the normal and control groups.

CONCLUSIONBuried penis affects the structure and function of corpus cavernosum in rats and the effect is positively correlated with the buried time, but there is no significant effect on the macroscopic development.

Animals ; Male ; Nitric Oxide Synthase ; metabolism ; Penis ; anatomy & histology ; pathology ; physiopathology ; Rats ; Rats, Sprague-Dawley

This study explored the usefulness of two-dimensional shear wave elastography (2D-SWE) in the early assessment of corpora cavernosa fibrosis (CCF). New Zealand male rabbits were randomly assigned to an experimental group or a control group. Recombinant human transforming growth factor beta 1 (TGF-β1) was injected into the dorsal penis tissue of rabbits in the experimental group. Conventional ultrasound and 2D-SWE examinations were performed before and 20 days after injection. Penile histological analysis was performed by hematoxylin-eosin staining, sirius red staining, and immunohistochemistry. Measurement of 2D-SWE examination results was performed using shear wave elastography quantitative measurement (SWQ). Histological analysis outcomes were the proportion of smooth muscle cells (SMCs), collagen fibers (CFs), collagen type I (Col I), and collagen type III (Col III), as well as the SMCs/CFs ratio, measured by sirius red staining. Other histological analysis outcomes were the positive area proportion (PAP) of TGF-β1 (PAP_T), fibronectin (PAP_F), and Col III (PAP_C), measured by immunohistochemistry. After recombinant human TGF-β1 injection, SWQ was higher in the experimental group than that in the control group (P < 0.001); however, there were no differences in conventional ultrasound results. There were significant differences in histological outcomes between the two groups (all P < 0.05). These results indicated that 2D-SWE was superior for identifying early histological changes in CCF.
Animals ; Elasticity Imaging Techniques/methods* ; Fibrosis ; Male ; Penis/pathology* ; Rabbits ; Transforming Growth Factor beta1/metabolism*

AIMTo clarify the ultrastructural changes of penile tunica albuginea (TA) in streptozotocin (STZ)-induced diabetic rats.

METHODSIntraperitoneal injection of STZ was used to induce diabetes mellitus (DM) in 12 Sprague Dawley rats. Ten rats (age and weight-matched) were used as control. Blood samples from the tail snips of the rats were used for the determination of serum glucose levels with SureStep Plus Blood Meter. At week 4 and 10 after the injection, half of the rats in each group were sacrificed and penile samples were obtained from the middle third of the penile shaft for the examination of TA under scanning electron microscopy.

RESULTSIn the diabetic group, the serum glucose levels were higher (P<0.01 at both time points) and the TA were thinner (P<0.05) than those of the controls. In the control group, the fibers of TA were rich and arranged regularly and undulated, while in the diabetic group, the fibers were diminished, lost the undulations and were arranged irregularly.

CONCLUSIONIn rats, DM appeared to impair the penile TA ultrastructures and this impairment could contribute to diabetic erectile dysfunction in part by impairing the veno-occlusive function.

Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; pathology ; Male ; Microscopy, Electron, Scanning ; Penis ; pathology ; ultrastructure ; Rats ; Rats, Sprague-Dawley

Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Carcinoma, Verrucous ; pathology ; Condylomata Acuminata ; pathology ; virology ; Diagnosis, Differential ; Human papillomavirus 11 ; isolation & purification ; Humans ; Hyperplasia ; Male ; Middle Aged ; Penile Diseases ; metabolism ; pathology ; virology ; Penile Neoplasms ; pathology ; Penis ; pathology ; Xanthomatosis ; metabolism ; pathology ; virology

OBJECTIVESTo investigate the effect of senility on inducible nitric oxide synthase (iNOS) expression and apoptosis in rat penis.

METHODSThe rats were divided into three groups randomly: senescent, aged and young. Their penises were harvested to detect iNOS expression by immunohistochemistry and cell apoptosis rate by TUNEL, respectively.

RESULTSiNOS expression were 0.24 +/- 0.03, 0.17 +/- 0.02, 0.12 +/- 0.03 (relative A) and cell apoptosis rate were (1.41 +/- 0.78)%, (0.94 +/- 0.43)% and (0.50 +/- 0.23 )%, respectively, in the tissues of three groups. The differences among three groups were considerable significance (P <0.05).

CONCLUSIONIt maybe one of the mechanisms of erectile dysfunction in the aging male that senility causes the increase of iNOS expression and cell apoptosis.

Aging ; metabolism ; pathology ; Animals ; Apoptosis ; In Situ Nick-End Labeling ; Male ; Nitric Oxide Synthase Type II ; biosynthesis ; Penis ; metabolism ; pathology ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVETo validate the hypothesis that the phenotypic transformation occurs in the smooth muscle cells in the corpus cavernosum of hypertensive rat and explore its impact on the erectile function of rats.

METHODSEighteen 16-week-old male spontaneously hypertensive rats (SHR) and 10 syngeneic normotensive rats (WKY) were used in this experiment. After measurement of systolic blood pressure of the caudal artery and examination of the erectile function with subcutaneous injection of apomorphine (APO), the rats were divided into 3 groups, namely hypertensive with erectile dysfunction (HBP-ED) group (n=6), hypertensive (HBP) group (n=12) and control group (n=10). Immunohistochemical staining and color image analysis system were used to observe expression of calponin 1 and osteopontin (OPN) in rat corpus cavernosum. Real-time quantitative RT-PCR was used to determine the expression of calponin 1 and OPN mRNAs in different groups.

RESULTSThe expressions of calponin 1 protein and mRNA were the highest in the control group and the lowest in HBP-ED group, while the expressions of OPN protein and mRNA were the highest in HBP-ED group and the lowest in the control group.

CONCLUSIONThe smooth muscle cells may transform from the contractile phenotype into synthetic phenotype in the corpus cavernosum of the hypertensive rats, resulting ultimately in erectile dysfunction.

Animals ; Calcium-Binding Proteins ; genetics ; metabolism ; Erectile Dysfunction ; etiology ; pathology ; Hypertension ; complications ; pathology ; Male ; Microfilament Proteins ; genetics ; metabolism ; Myocytes, Smooth Muscle ; pathology ; Osteopontin ; genetics ; metabolism ; Penis ; pathology ; Phenotype ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Inbred SHR

OBJECTIVETo explore the effect of hypoxia on the fibrosis of corpus cavernosum smooth muscle cells (CCSMC) in SD rats.

METHODSCCSMCs were cultured in vitro, identified by immunohistochemistry, and then exposed to hypoxia at the concentration of 1% O2 for 12, 24, 48 and 72 hours. Those exposed to normal oxygen concentration for the corresponding lengths of time were used as the control. The relative expressions of TGF-131, type I collagen and type DI collagen were determined by RT-PCR.

RESULTSThe in vitro cultured CCSMCs grew well, and the anti-a-smooth muscle actin monoclonal antibodies were positive on immunohistochemical staining. The relative expression levels of TGF-beta1, type I collagen and type mI collagen were positively correlated with the time of hypoxia interference within 48 hours, and did not increase further with prolonged exposure.

CONCLUSIONWhen exposed to hypoxia, the relative expressions of TGF-beta1, type I collagen and type mI collagen in the CCSMCs of SD rats increased with the length of time, and reached the peak at 48 hours. Hypoxia can cause fibrosis of CCSMCs in SD rats.

Animals ; Cell Hypoxia ; Cells, Cultured ; Collagen Type I ; metabolism ; Extracellular Matrix ; Fibrosis ; Male ; Muscle, Smooth ; cytology ; pathology ; Oxygen ; metabolism ; Penis ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta1 ; metabolism

Silent information regulator 2-related enzyme 1 (SIRT1) is an aging-related protein activated with aging. Herein, we evaluated the role of SIRT1 in aging-related erectile dysfunction. The expression of SIRT1 was modulated in aged Sprague-Dawley rats following intragastric administration of resveratrol (Res; 5 mg kg^-1), niacinamide (NAM; 500 mg kg^-1) or Res (5 mg kg^-1) + tadalafil (Tad; phosphodiesterase-5 [PDE5] inhibitor; 5 mg kg^-1) for 8 weeks. Then, we determined erectile function by the ratio of intracavernosal pressure (ICP)/mean systemic arterial pressure (MAP). Cavernosal tissues were extracted to evaluate histological changes, cell apoptosis, nitric oxide (NO)/cyclic guanosine monophosphate (cGMP), the superoxide dismutase (SOD)/3,4-methylenedioxyamphetamine (MDA) level, and the expression of SIRT1, p53, and forkhead box O3 (FOXO3a) using immunohistochemistry, terminal deoxynucleotidyl transferase (TdT)-mediated 2'-deoxyuridine 5'-triphosphate (dUTP) nick-end labeling (TUNEL), enzyme-linked immunosorbent assays, and western blot analysis. Compared with the control, Res treatment significantly improved erectile function, reflected by an increased content of smooth muscle and endothelium, NO/cGMP and SOD activity, and reduced cell apoptosis and MDA levels. The effect of Res was improved by adding Tad. In addition, the protein expression of SIRT1 was increased in the Res group, accompanied by decreased p53 and FOXO3a levels. In addition, inhibition of SIRT1 by NAM treatment resulted in adverse results compared with Res treatment. SIRT1 activation ameliorated aging-related erectile dysfunction, supporting the potential of SIRT1 as a target for erectile dysfunction treatment.
Animals ; Male ; Rats ; Cyclic GMP/metabolism* ; Erectile Dysfunction/metabolism* ; Nitric Oxide/metabolism* ; Penile Erection ; Penis/pathology* ; Phosphodiesterase 5 Inhibitors/pharmacology* ; Rats, Sprague-Dawley ; Sirtuin 1/metabolism* ; Superoxide Dismutase/metabolism* ; Tumor Suppressor Protein p53/metabolism*

OBJECTIVETo evaluate the impact of nicotine- and tar-free cigarette smoke extract (fCSE) on the serum testosterone (T) level and erectile function of male rats.

METHODSWe randomized 30 male SD rats to three groups of equal number to receive subcutaneous injection of PBS (1.0 ml / 300 g body weight per day), fCSE (1.0 ml/300 g body weight per day), and reduced glutathione hormone (GSH, 200 mg per kg body weight per day) in addition to fCSE (fCSE + GSH), respectively, all for 8 weeks. Then we evaluated the erectile function of the rats by measuring the maximal intracavernous pressure (MICP), mean arterial pressure (MAP), ICP/MAP ratio, time of stimulation to MICP (Tmax), and cavernosal filling fate (CFR). We determined the serum T level, the activities of superoxide dismutase (SOD) , malondialdehyde (MDA), and nitric oxide synthase (NOS) in the cavernosal tissue, and also observed the morphological changes of the corpus cavernosum.

RESULTSCompared with the controls, the rats of the fCSE group showed obvious decreases in the levels of serum T ([5.37 ± 1.43] vs [3.22 ± 1.11] μg/L), NOS ([2.90 ± 0.27] vs [1.67 ± 0.18] U/mg) , and SOD ([18.41 ± 1.09] vs [13.36 ± 1.18] U/mg prot) and erectile function-related indexes MICP ([85.92 ± 6.36] vs [58.99 ± 10.76] mmHg), MICP/MAP (0.86 ± 0.09 vs [0.56 ± 0.08]), and CFR (2.14 ± 0.44 vs 0.89 ± 0.44), but markedly increased Tmax ([29.90 ± 5.78] vs [42.90 ± 8.56]s), with a positive correlation between the serum T level and CFR (r = 0. 364, P < 0.05). Masson staining revealed a lower ratio of the corpus cavernosum smooth muscle tissue to collagen fiber in the fCSE group (0.27 ± 0.04) than in the control (0.98 ± 0.12). Compared with the fCSE group, the fCSE + GSH group exhibited significantly improved MICP ([58.99 ± 10.76 ] vs [77.95 ± 7.71] mmHg), MICP/MAP (0.56 ± 0.08 vs 0.77 ± 0.09), and CFR (0.89 ± 0.44] vs 1.76 ± 0.42) and shortened Tmax ([42.90 ± 8.56 ] vs [32.10 ± 5.84 ] s). The ratio of the corpus cavernosum smooth muscle tissue to collagen fiber was higher in the fCSE + GSH than in the fCSE group (0.77 ± 0.09 vs 0.27 ± 0.04) but still lower than in the control (0.98 ± 0.12).

CONCLUSIONNicotine- and tar-free cigarette smoke extract reduces the serum T level and erectile function of rats, which is related to oxidative stress. Antioxidant therapy can improve erectile function but has a limited value for morphological protection of the penile tissue.

Animals ; Erectile Dysfunction ; chemically induced ; Male ; Malondialdehyde ; metabolism ; Muscle, Smooth ; pathology ; Nicotine ; Nitric Oxide Synthase ; metabolism ; Penile Erection ; drug effects ; Penis ; pathology ; Rats ; Rats, Sprague-Dawley ; Smoke ; adverse effects ; Superoxide Dismutase ; metabolism ; Tars ; Tobacco ; adverse effects

OBJECTIVETo explore the characteristics of cell apoptosis and proliferation of corpus cavernosum smooth muscle (CCSM) cells in diabetic rats.

METHODSFrom a SD rat model of diabetes induced by a single dose of streptozotocin, CCSM cells were isolated for primary culture and identified using immunocytochemical assays for SMα-actin. The proliferation of CCSM cells was evaluated by WST-1 assay, and flow cytometry was used to detect the cells apoptosis. Real-time fluorescence quantitative RT-PCR (qRT-PCR) was used to analyze the relative expression of proliferation cell nucleus antigen (PCNA) and caspase-3 mRNA.

RESULTSThe proliferation rate of the primarily cultured CCSM cells from diabetic rats was significantly decreased and the apoptosis rate significantly increased compared with those of the cells from the control rats. The expression of PCNA mRNA was significantly lowered while caspase-3 mRNA significantly increased in the corpus cavernosum of the diabetic rats (P<0.001).

CONCLUSIONIn rats with persisted hyperglycemia, a higher apoptosis rate and a lower proliferation rate both contribute to the reduction of CCSM cells.

Animals ; Apoptosis ; physiology ; Cell Proliferation ; Diabetes Mellitus, Experimental ; pathology ; Male ; Myocytes, Smooth Muscle ; pathology ; Penis ; cytology ; physiopathology ; Primary Cell Culture ; Proliferating Cell Nuclear Antigen ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley