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Zhong-Cheng Xin

Publications and source records attributed to Zhong-Cheng Xin.

13 recordsLinked to original sources
PubMed2006

Cox7a2 mediates steroidogenesis in TM3 mouse Leydig cells.

AIM: To investigate the regulatory function of Cox7a2 on steroidogenesis and the mechanism involved in TM3 mouse Leydig cells. METHODS: The cDNA of Cox7a2 was cloned from TM3 mouse Leydig cells. It was subcloned to pDsRed-Express-N1 and transfected back into TM3 mouse Leydig cells for Cox7a2 overexpression by transient gene transfection. Steroidogenesis affected by overexpressed Cox7a2 was studied by ELISA. To elicit the mechanism of this effect, expression of steroidogenic acute regulatory (StAR) protein and reactive oxygen species (ROS) were examined by Western blot and fluorometer, respectively. RESULTS: The cDNA of Cox7a2 (249 bp) was cloned from Leydig cells and confirmed by DNA sequencing. After constructed pDsRed-Express-N1-Cox7a2 was transfected back into TM3 mouse Leydig cells, Cox7a2 inhibited not only luteinizing hormone (LH)-induced secretion of testosterone but also the expression of StAR protein. At the same time, Cox7a2 increased the activity of ROS in TM3 mouse Leydig cells. CONCLUSION: Cox7a2 inhibited LH-induced StAR protein expression, and consequent testosterone production, at least in part, by increasing ROS activity in TM3 mouse Leydig cells.

Animals↗
PubMed2006

Phosphodiesterase-5 isoforms: differential cyclic guanyl monophosphate binding and cyclic guanyl monophosphate catalytic activities, and inhibitory effects of sildenafil and vardenafil.

PURPOSE: We determined the differential cyclic guanyl monophosphate catalytic and cyclic guanyl monophosphate binding activity of phosphodiesterase-5 isoforms and the inhibitory effects of sildenafil (Pfizer, New York, New York) and vardenafil (Bayer Pharmaceutical Research, Wuppertal, Germany). MATERIALS AND METHODS: Coding sequences of the human phosphodiesterase-5 isoforms A1, A2 and A3 were cloned into pBlueBac4.5/V5-His (Invitrogen, Carlsbad, California), which allows the tagging of histidines at the carboxyl terminal of the expressed protein. Isoforms were expressed with the Bac-N-Blue baculoviral system and purified with the ProBond system. Expression clones were identified by polymerase chain reaction using vector and phosphodiesterase-5 specific primers. Purified proteins were verified by Western blotting. Purified proteins were analyzed for cyclic guanyl monophosphate catalytic and cyclic guanyl monophosphate binding activity, and used to determine the differential potencies of the phosphodiesterase-5 selective inhibitors sildenafil and vardenafil. RESULTS: Cloning and expression of phosphodiesterase-5A1 to A3 isoforms in the baculoviral system resulted in the isolation of purified isoform proteins. Mean cyclic guanyl monophosphate catalytic activity (K(m)) +/- SD was 4.76 +/- 0.37, 4.52 +/- 0.09 and 11.39 +/- 0.22 microM for A1 to A3, respectively. Mean cyclic guanyl monophosphate binding activity (K(d)) was 3.24 +/- 0.47, 1.95 +/- 0.60 and 1.70 +/- 0.47 microM for A1 to A3, respectively. Mean IC(50) of sildenafil against phosphodiesterase-5A1 to A3 was 1.20 +/- 0.34, 2.83 +/- 0.56 and 2.28 +/- 0.38 nM, respectively. Mean IC(50) of vardenafil against phosphodiesterase-5A1 to A3 was 0.41 +/- 0.15, 0.23 +/- 0.08 and 0.45 +/- 0.06 nM, respectively. CONCLUSIONS: Phosphodiesterase-5A1 and A2 had similar K(m) values, while phosphodiesterase-5A3 had a much higher K(m) and, thus, lower cyclic guanyl monophosphate catalytic activity. Phosphodiesterase-5A2 and A3 had similar K(d) values, while phosphodiesterase-5A1 had higher K(d) and, thus, lower cyclic guanyl monophosphate binding activity. Vardenafil was more potent (3 to 12-fold) than sildenafil for inhibiting the catalytic activity of all 3 human phosphodiesterase-5 isoforms with phosphodiesterase-5A2 showing the highest differentiation (12-fold).

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2006

Effects of icariin on phosphodiesterase-5 activity in vitro and cyclic guanosine monophosphate level in cavernous smooth muscle cells.

OBJECTIVES: To investigate the effect of icariin on the cyclic guanosine monophosphate (cGMP)-hydrolytic activity of phosphodiesterase-5 (PDE5) isoforms and the cGMP levels in cavernous smooth muscle cells treated with sodium nitroprusside (SNP). METHODS: PDE5 isoforms (PDE5A1, A2, and A3) were isolated from sf9 insect cells infected with baculoviruses carrying PDE5 isoform cDNA. Icariin was isolated from Epimedii herba. Varying amounts (10(-6) to 10(-11) M) of icariin or zaprinast were added to reaction mixtures containing PDE5 isoforms and cGMP. The inhibitory effects of icariin and zaprinast were analyzed by GraphPad Software and are expressed as concentration that inhibits 50% (IC50) values. Cavernous smooth muscle cells were isolated from 3-month-old rats, treated with icariin (100 and 200 microM) or zaprinast (200 microM) for 15 minutes, and then with 10 microM SNP for 30, 60, 120, 240, and 360 minutes. The cells were then analyzed for the cGMP concentration using an enzyme immunoassay system. RESULTS: Icariin inhibited PDE5A1, A2, and A3 with an IC50 value of 1.0, 0.75, and 1.1 microM, respectively. The corresponding IC50 values for zaprinast were 0.33, 0.23, and 0.32 microM. Icariin consistently outperformed the control (SNP-only treatment) in maintaining greater cGMP levels, particularly at the greater concentration of 200 microM. In contrast, zaprinast at 200 microM did better than the control only at 60 and 360 minutes. CONCLUSIONS: Icariin was inhibitory to all three PDE5 isoforms with similar IC50 values, which were approximately three times greater than those for zaprinast. Icariin was able to enhance cGMP levels in SNP-treated cavernous smooth muscle cells.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2006

Expression, distribution and regulation of phosphodiesterase 5.

Phosphodiesterase 5 (PDE5) is one of eleven members of the mammalian phosphodiesterase family that hydrolyzes cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP). Best known as the target of the impotence drug sildenafil, PDE5 degrades cGMP in smooth muscle cells so as to maintain the contracted state of contractile organs such as the penis, blood vessels, uterus, and intestines. In addition, it regulates numerous other physiological processes such as neurogenesis and apoptosis. Like all other PDEs, PDE5 is dimeric; each subunit is approximately 100 kd in size and has two allosteric cGMP-binding sites and a catalytic domain. Protein kinase G (PKG)-mediated phosphorylation and allosteric cGMP binding upregulate PDE5 activity, while PP1 phosphatase-mediated dephosphorylation downregulates. Sildenafil and other selective inhibitors inhibit PDE5 by binding to the catalytic site. From two promoters a single PDE5A gene at human chromosome 4q26 encodes three alternatively spliced isoforms (PDE5A1-3) that differ in the N-terminus. The PDE5A promoter is located upstream of the three isoform-specific first exons (in the order of A1-A3-A2) and consists of a 139-bp core, a 308-bp upstream enhancer, and a 156-bp downstream enhancer. The weaker 182-bp PDE5A2 promoter is located between the A3- and A2-specific exons and contains an indispensable Sp1-binding sequence. Both promoters are responsive to cGMP or cAMP stimulation, and several studies have demonstrated regulation of PDE5 expression possibly through these promoters. Virtually all tissues and cell types express PDE5, with heart and cardiomyocytes being contentious. PDE5A1 and PDE5A2 are ubiquitous, but PDE5A3 is specific to smooth muscle.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2005

Effects of icariin on erectile function and expression of nitric oxide synthase isoforms in castrated rats.

AIM: To investigate the effect of icariin on erectile function and the expression of nitric oxide synthase (NOS) isoforms in castrated rats. METHODS: Thirty-two adult male Wistar rats were randomly divided into one sham-operated group (A) and three castrated groups (B, C and D). One week after surgery, rats were treated with normal saline (groups A and B) or oral icariin (1 mg/[kg.day] for group C and 5 mg/[kg.day] for group D) for 4 weeks. One week after treatment, the erectile function of the rats was assessed by measuring intracavernosal pressure (ICP) during electrostimulation of the cavernosal nerve. The serum testosterone (ST) levels, the percent of smooth muscle (PSM) in trabecular tissue, and the expression of mRNA and proteins of neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and phosphodiesterase V (PDE5) in corpus cavernosum (CC) were also evaluated. RESULTS: ICP, PSM, ST and the expression of nNOS, iNOS, eNOS and PDE5 were significantly decreased in group B compared with those in group A (P 0.01). However, ICP, PSM and the expression of nNOS and iNOS were increased in groups C and D compared with those in group B (P 0.05). Changes in ST and the expression of eNOS and PDE5 were not significant (P 0.05) in groups C and D compared with those in group B. CONCLUSION: Oral treatment with icariin ( 98.6 % purity) for 4 weeks potentially improves erectile function. This effect is correlated with an increase in PSM and the expression of certain NOS in the CC of castrated rats. These results suggest that icariin may have a therapeutic effect on erectile dysfunction.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2004

[Effects of icariin on the erectile function and expression of nitrogen oxide synthase isoforms in corpus cavernosum of arterigenic erectile dysfunction rat model].

OBJECTIVE: The study the effects of oral administered icariin on intracavernosal pressure (ICP) and on expression of the nitrogen oxide synthase (NOS) isoforms in corpus cavernosum (CC) of arteriogenic erectile dysfunction (A-ED) rat model. METHODS: Forty adult male Wistar rats were randomly divided into 4 groups of 10 rats: shame operated group (group A) and three A-ED model groups (group B, C and D). The internal pudendal arteries were isolated and ligated with 7-O nylon thread at both the main trunk and the penile branches to establish the A-ED model. ICP were tested after the operation to make sure the successful model establishment. The groups A and B were treated with saline: and the groups C and D were treated with icariin (5 mg/kg/day and 10mg/kg/day respectively) orally for 30 days. Then the ICP was measured again. The tissues of corpus cavernosum were taken and RT-PCR was used to detect the mRNA expression of nNOS, iNOS and eNOS in CC, and Western-blot was used to detect the protein expression of these NOS isoforms. RESULTS: The ICP in the group B was significantly decreased compared to the group A (P < 0.01), but the ICP values in the groups C and D were both increased compared to those in the group B (both P < 0.01). The expressions of the mRNA and protein of nNOS, iNOS, and eNOS were all decreased in the group B, however, the mRNA and protein expressions of eNOS were increased a in the groups C and D. In the group C, iNOS also increased. The expression of nNOS showed no obvious changes in the group C and group D. CONCLUSION: Chronic oral treatment with Icariin increases the erectile function (ICP) and restores the eNOS expression in CC of A-ED rats. Icariin may have a long-term therapeutic effect on ischemia/hypoxia induced ED.

Animals↗
PubMed2004

Effect of renewed SS-cream on spinal somatosensory evoked potential in rabbits.

AIM: The effect of a renewed SS-cream (RSSC) on the treatment of premature ejaculation (PE) was evaluated and compared with the original SS-cream (OSSC). METHODS: Sixty male white New Zealand rabbits, weighing 2.5 kg-3.0 kg, were divided at random into 3 groups: the RSSC, OSSC and placebo groups. The spinal somatosensory evoked potential (SSEP) elicited by electric stimulation of the glans penis with disk electrode was investigated with an electrophysiograph (Poseidomn, Shanghai, China) before and 10, 30 and 60 min after drug or placebo application on the glans. The Onset and the N1 latencies and the amplitude of SSEP were recorded and analyzed. RESULTS: There was no significant difference (P>0.05) in the mean Onset and N1 latency of SSEP among the 3 groups before drug application. Compared with the pre-application value, the mean Onset and N1 latencies in the RSSC and OSSC groups were significantly prolonged at 10, 30 and 60 min after treatment (P<0.05), while they were not significantly changed (P>0.05) in the placebo group. The mean Onset latency of RSSC at 10 and 30 min and that of OSSC at 30 min were significantly delayed (P<0.05) compared with the placebo group. The mean N1 latency of RSSC at 30 and 60 min and that of OSSC group at 30 min were also significantly delayed (P<0.05). CONCLUSION: RSSC delays the latencies of SSEP, suggesting a local desensitizing effect on the sensory receptor of the glans penis dorsal nerve, which provides the potential for PE treatment. The desensitizing effect of RSSC is higher than that of OSSC.

Amphibian Venoms↗
PubMed2004

Sexual function of premature ejaculation patients assayed with Chinese Index of Premature Ejaculation.

AIM: To assess the psychometric properties of the Chinese Index of Premature Ejaculation (CIPE). METHODS: The sexual function of 167 patients with and 114 normal controls without premature ejaculation (PE) were evaluated with CIPE. All subjects were married and had regular sexual activity. The CIPE has 10 questions, focusing on libido, erectile function, ejaculatory latency, sexual satisfaction and difficulty in delaying ejaculation, self-confidence and depression. Each question was responded to on a 5 point Likert-type scale. The individual question score and the total scale score were analyzed between the two groups. RESULTS: There were no significant differences between the age, duration of marriage and educational level (P> 0.05) of patients with and without PE and normal controls. The mean latency of patients with PE and normal controls were 1.6 +/- 1.2 and 10.2 +/- 9.5 minutes, respectively. Significant differences between patients with (26.7 +/- 4.6) PE and normal controls (41.9 +/- 4.0) were observed on the total score of CIPE (P< 0.01). Using binary logistic regression analysis, PE was significantly related to five questions of the original measure. They are the so-called the CIPE-5 and include: ejaculatory latency, sexual satisfaction of patients and sexual partner, difficulty in delaying ejaculation, anxiety and depression. Receiver Operating Characteristic (ROC) curve analysis of CIPE-5 questionnaire indicated that the sensitivity and specificity of CIPE were 97.60 % and 94.74 %, respectively. Employing the total score of CIPE-5, patients with PE could be divided into three groups: mild (>15 point) 19.8 %, moderate (10-14 point) 62.8 % and severe (< 9 point) 16.7 %. CONCLUSION: The CIPE-5 is a useful method for the evaluation of sexual function of patients with PE and can be used as a clinical endpoint for clinical trials studying the efficacy of pharmacological intervention.

Adult↗
PubMed2003

Up and down-regulation of phosphodiesterase-5 as related to tachyphylaxis and priapism.

PURPOSE: We identify whether tachyphylaxis and priapism effects of sildenafil are related to regulation of phosphodiesterase-5 (PDE-5) expression. MATERIALS AND METHODS: Cavernous smooth muscle cells (CSMCs) were isolated from young rats and treated with 0, 1, 10 and 25 microM sildenafil with or without 100 microM of sodium nitroprusside for 3 and 7 days. The cells were subjected to reverse transcriptase-polymerase chain reaction and Western blot analysis for PDE-5 expression. Plasmid constructs carrying PDE-5A1 and PDE-5A2 promoters were transfected into COS-7 cells, treated with 25 microM sildenafil and analyzed for promoter activities. To simulate priapism, CSMCs were cultured under anoxia or hypoxia and then analyzed for PDE-5 expression. Furthermore, rats underwent bilateral pudendal arterial ligation for 1 day to 14 weeks, and corpus cavernous tissues were subjected to reverse transcriptase-polymerase chain reaction analysis for PDE-5 expression. RESULTS: Up-regulation of PDE-5 was noted in CSMCs treated with 25 microM sildenafil for 7 days. PDE-5 messenger RNA and protein levels were significantly increased in the 7-day sildenafil treated cultures. Sodium nitroprusside appeared to down-regulate PDE-5 expression. Sildenafil significantly increased the activities of PDE-5A1 promoter. PDE-5 expression was significantly reduced under anoxia and hypoxia. The corpus cavernous tissue showed a gradual decrease in PDE-5 expression under ischemia. CONCLUSIONS: Repeated treatment with sildenafil at high concentrations was needed to simulate tachyphylaxis in our cell culture system. Adequate oxygenation was important for PDE-5 expression. Thus, sicklemic patients may express PDE-5 at abnormally low levels, predisposing them at risk of stuttering priapism.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2003

[Spontaneous high flow arterial priapism of old males(one case report and review)].

OBJECTIVES: To investigate the correlation between corpus cavernosum disruption and high-flow priapism for the understanding of high-flow priapism and its treatment. METHODS: To report the clinical data of a case of spontaneous idiopathic high-flow priapism. RESULTS: The diagnosis was made as right cavernosal artery disruption after angiography. The result of cavernosal blood gas analysis was normal. The penis became detumescent after the gelatin embolization treatment was performed. CONCLUSIONS: Spontaneous high-flow priapism of old people(non-ischemic) is rare in clinic. Blood gas analysis and angiography are needed to find the hemorrhage site when conservative treatment fails. Gelatin embolization or cavernosal artery ligation are usually effective in the subsequent treatment.

Angiography↗
PubMed2002

[Physicians' knowledge and attitude to erectile dysfunction].

OBJECTIVES: The physicians knowledge and attitude to erectile dysfunction (ED) is very important to the diagnosis and management of this disease. We investigated the physicians and practitioners knowledge of ED, attitude to ED, and if they actively find the underlying ED patients. METHODS: Three hundreds and one physicians and practitioners in Beijing completed a questionnaire. The subjects included urologists, cardiologists, endocrinologists, surgeons, orthopaedicians and community practitioners. RESULTS: The definition of ED was well known by most subjects (83.4%). Many agreed that ED was a common condition in the aging men (85.0%), and it was an important health problem (78.7%) and it was the local signs of certain systemic diseases (89.7%). The most common risk factors of ED enumerated by the physicians were diabetes (45.5%), hypertension (12.6%) and coronary artery diseases (12.0%). 45.5% physicians met the patients who initiated questions about ED. 32.6% physicians would discuss ED with the patients if the patients initiate questions about ED. 95.0% non-urological physicians would refer the ED patients to urologists or andrologists. 43.5% of all the physicians never asked their patients about erectile function, this proportions in the subgroups of urologists, non-urological physicians and community practitioners were 7.2%, 55.3% and 60.5% respectively (P < 0.01). The most common reasons for the physicians not to initiate the inquiries about ED was "the patients would not have ED if they didnt complain about it" (42.2%), "there was no ED patients in my specialty" (20.9%), "diagnosis and treatment of ED was not my business" (17.3%), "have no time" (15.6%), "feel embarrassed" (13.6%). CONCLUSIONS: Most physicians regarded ED as an important health problem and a common condition in aging men, but they didnt take an active attitude to ED in their clinical practice.

Aging↗
PubMed2002

[Advances in the research about penile erection related genes].

Molecular biologic research on erectile dysfunction (ED), especially the elucidation of NO-cGMP signaling pathway which plays an important role on modulating corpus cavernosum smooth muscle dilation, has been made the great advance in past ten years. The further research on the penile erection related genes including nitric oxide synthase (NOS), phosphodiesterases (PDEs), K+ channal, insulin-like growth factor (IGF), heme oxygenase (HO), vascular endothelial growth factor (VEGF), cyclic GMP-dependent kinase (cGK I), angiotensin converting enzyme (ACE) and growth factor (GF) etc, has given the theoretical evidence for the clinical treatment of ED in future.

Cyclic GMP-Dependent Protein Kinases↗