This study was designed to investigate the cardiovascular effects of sulfur dioxide (SO₂) in the caudal ventrolateral medulla (CVLM) of anesthetized rats and its mechanism. Different doses of SO₂ (2, 20, 200 pmol) or artificial cerebrospinal fluid (aCSF) were injected into the CVLM unilaterally or bilaterally, and the effects of SO₂ on blood pressure and heart rate of rats were observed. In order to explore the possible mechanisms of SO₂ in the CVLM, different signal pathway blockers were injected into the CVLM before the treatment with SO₂ (20 pmol). The results showed that unilateral or bilateral microinjection of SO₂ reduced blood pressure and heart rate in a dose-dependent manner (P < 0.01). Moreover, compared with unilateral injection of SO₂ (2 pmol), bilateral injection of 2 pmol SO₂ produced a greater reduction in blood pressure. Local pre-injection of the glutamate receptor blocker kynurenic acid (Kyn, 5 nmol) or soluble guanylate cyclase (sGC) inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 1 pmol) into the CVLM attenuated the inhibitory effects of SO₂ on both blood pressure and heart rate. However, local pre-injection of nitric oxide synthase (NOS) inhibitor N^G-Nitro-L-arginine methyl ester (L-NAME, 10 nmol) only attenuated the inhibitory effect of SO₂ on heart rate but not blood pressure. In conclusion, SO₂ in rat CVLM has cardiovascular inhibitory effects, and its mechanism is related to the glutamate receptor and NOS/cGMP signal pathways.
Animals ; Rats ; Heart Rate ; Sulfur Dioxide ; Blood Pressure ; Cyclic GMP ; Receptors, Glutamate

OBJECTIVE: This study aimed to investigate the regulation of histone-like nucleoid structuring protein (H-NS) on biofilm formation and cyclic diguanylate (c-di-GMP) synthesis in Vibrio parahaemolyticus RIMD2210633. METHODS: Regulatory mechanisms were analyzed by the combined utilization of crystal violet staining, quantification of c-di-GMP, quantitative real-time polymerase chain reaction, LacZ fusion, and electrophoretic-mobility shift assay. RESULTS: The deletion of hns enhanced the biofilm formation and intracellular c-di-GMP levels in V. parahaemolyticus RIMD2210633. H-NS can bind the upstream promoter-proximal DNA regions of scrA, scrG, VP0117, VPA0198, VPA1176, VP0699, and VP2979 to repress their transcription. These genes encode a group of proteins with GGDEF and/or EAL domains associated with c-di-GMP metabolism. CONCLUSION One of the mechanisms by which H-NS represses the biofilm formation by V. parahaemolyticus RIMD2210633 may be via repression of the production of intracellular c-di-GMP.
Bacterial Proteins/metabolism* ; Biofilms ; Cyclic GMP/analogs & derivatives* ; Gene Expression Regulation, Bacterial ; Gentian Violet ; Histones/metabolism* ; Vibrio parahaemolyticus/genetics*

Escherichia coli biofilm is a complex membrane aggregation produced by the adhesion and secretion of extracellular polymeric substances by E. coli cells aggregated on specific media. Pathogenic E. coli will evade the immune system and the impact of various harmful factors in the environment after the formation of biofilm, causing sustained and even fatal damage to the host. Cyclic diguanosine monophosphate (c-di-GMP) is a second messenger ubiquitous in bacteria and plays a crucial role in regulating biofilm formation. This paper reviewed the recent studies about the role of c-di-GMP in the movement, adhesion, and EPS production mechanism of E. coli during biofilm formation, aiming to provide a basis for inhibiting E. coli biofilm from the perspective of c-di-GMP.
Bacterial Proteins/genetics* ; Biofilms ; Cyclic GMP/analogs & derivatives* ; Escherichia coli/metabolism* ; Escherichia coli Proteins/metabolism* ; Gene Expression Regulation, Bacterial

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*

OBJECTIVE: To evaluate the therapeutic effect of the combined treatment with balance acupuncture therapy and exercise re-learning rehabilitation therapy and the impact on serum cAMP and cGMP in the patients with hemiplegia of cerebral ischemic stroke. METHODS: A total of 90 patients of hemiplegia of cerebral ischemic stroke were randomized into an observation group and a control group, 45 cases in each one. All of the patients in the two groups received health education, diet guidance, routine symptomatic treatment as well as exercise re-learning rehabilitation therapy. Additionally, in the observation group, balance acupuncture therapy was applied, in which, the acupoints on the aspect of the human body, on the governor vessel and bladder meridian were adopted in the morning and those on the aspect of the human body, on the conception vessel and kidney meridian were stimulated in the afternoon. In the control group, the regular acupuncture was given. In the two groups, both acupuncture and rehabilitation therapies were given 5 days a week, 2 week-treatment as one course and totally 2 courses were required. Separately, before and after treatment, the score of Fugl-Meyer assessment (FMA) and the score of Chinese stroke scale (CSS) were recorded, the levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) detected in serum and the clinical therapeutic effect were evaluated in the two groups. RESULTS: After treatment, FMA score was increased in the patients of either of the groups as compared with that before treatment (<0.01) and CSS score decreased as compared with that before treatment (<0.01). After treatment, FMA score in the observation group was higher than that in the control group (<0.01) and CSS score was lower than the control group (<0.01). After treatment, the level of serum cAMP of the patients in either of the groups was increased as compared with that before treatment (<0.01) and that of cGMP decreased as compared with that before treatment (<0.01). After treatment, the level of cAMP in the observation group was higher than that in the control group (<0.01) and that of cGMP was lower than the control group (<0.01). The total effective rate was 93.3% (42/45) in the observation group, better than 73.3% (33/45) in the control group (<0.01). CONCLUSION The balance acupuncture therapy combined with exercise re-learning rehabilitation effectively improves the motor function of the affected limb, relieves injury and regulate the levels of serum cAMP and cGMP in the patients with hemiplegia of ischemic stroke.
Acupuncture Points ; Acupuncture Therapy ; Brain Ischemia ; therapy ; Cyclic AMP ; blood ; Cyclic GMP ; blood ; Hemiplegia ; therapy ; Humans ; Stroke ; therapy ; Stroke Rehabilitation ; Treatment Outcome

PURPOSE: Phosphodiesterase (PDE) inhibitors increase matrix metalloproteinase (MMP) production by inhibiting re-uptake of adenosine and may potentiate nitric oxide (NO) activity. This study was performed to investigate the effects and mechanisms of PDE inhibitors on trabecular outflow in cultured human trabecular meshwork cells (HTMCs). METHODS: Primary HTMC cultures were exposed to 0, 20, and 50 µM dipyridamole (DPD) or theophylline (TPN). Permeability through the HTMC monolayer was assessed using carboxyfluorescein. The production of NO was assessed using the Griess assay and MMP-2 levels were measured via Western blotting. RESULTS: DPD significantly increased permeability accompanied with increased nitrite concentration and MMP-2 levels (all p < 0.05). TPN increased nitrite but did not affect permeability or MMP-2 levels significantly (p > 0.05). When treated with DPD and TPN together, both permeability and nitrite production were increased; however, MMP-2 levels showed no difference compared to DPD exposure alone (p > 0.05). CONCLUSIONS: DPD increased trabecular permeability accompanied with increased nitrite production and MMP-2 levels. PDE inhibitors may increase trabecular outflow by increasing MMP-2 levels and by potentiating NO activity through cyclic GMP in HTMC.
Adenosine ; Blotting, Western ; Cyclic GMP ; Dipyridamole ; Humans ; Matrix Metalloproteinases ; Nitric Oxide ; Permeability ; Phosphodiesterase Inhibitors ; Theophylline ; Trabecular Meshwork

Bacterial biofilm refers to a tunicate-like biological group composed of polysaccharide, protein and nucleic acid secreted by bacteria on the surface of the mucous membrane or biological material. The biofilm formation is a major cause of chronic infections. Bacteria could produce some secondary metabolites during the growth and reproduction. Some of them act as signaling molecules allowing bacteria to communicate and regulate many important physiological behaviors at multiple-cell level, such as bioluminescence, biofilm formation, motility and lifestyles. Usually, these signal molecules play an important role in the formation of bacterial biofilm. We review here the effects of related signal molecules of Quorum Sensing, cyclic diguanylate, Two-Component Systems and sRNA on the biofilm formation. Focusing on these regulation mechanism of signal molecules in the process of biofilm formation is necessary for the prevention and treatment of some chronic diseases.
Bacterial Proteins ; Biofilms ; Cyclic GMP ; Gene Expression Regulation, Bacterial ; Protein Binding ; Quorum Sensing

OBJECTIVETo investigate the effect and potential mechanisms of rutaecarpine (Rut) in a rat artery balloon-injury model.

METHODSThe intimal hyperplasia model was established by rubbing the endothelia with a balloon catheter in the common carotid artery (CCA) of rats. Fifty rats were randomly divided into five groups, ie. sham, model, Rut (25, 50 and 75 mg/kg) with 10 rats of each group. The rats were treated with or without Rut (25, 50, 75 mg/kg) by intragastric administration for 14 consecutive days following injury. The morphological changes of the intima were evaluated by hematoxylin-eosin staining. The expressions of proliferating cell nuclear antigen (PCNA) and smooth muscle (SM) α-actin in the ateries were assayed by immunohistochemical staining. The mRNA expressions of c-myc, extracellular signal-regulated kinase 2 (ERK2), MAPK phosphatase-1 (MKP-1) and endothelial nitric oxide synthase (eNOS) were determined by real-time reverse transcription-polymerase chain reaction. The protein expressions of MKP-1 and phosphorylated ERK2 (p-ERK2) were examined by Western blotting. The plasma contents of nitric oxide (NO) and cyclic guanosine 3',5'-monophosphate (cGMP) were also determined.

RESULTSCompared with the model group, Rut treatment significantly decreased intimal thickening and ameliorated endothelial injury (P<0.05 or P<0.01). The positive expression rate of PCNA was decreased, while the expression rate of SM α-actin obviously increased in the vascular wall after Rut (50 and 75 mg/kg) administration (P<0.05 or P<0.01). Furthermore, the mRNA expressions of c-myc, ERK2 and PCNA were downregulated while the expressions of eNOS and MKP-1 were upregulated (P<0.05 or P<0.01). The protein expressions of MKP-1 and the phosphorylation of ERK2 were upregulated and downregulated after Rut (50 and 75 mg/kg) administration (P<0.05 or P<0.01), respectively. In addition, Rut dramatically reversed balloon injury-induced decrease of NO and cGMP in the plasma (P<0.05 or P<0.01).

CONCLUSIONRut could inhibit the balloon injury-induced carotid intimal hyperplasia in rats, possibly mediated by promotion of NO production and inhibiting ERK2 signal transduction pathways.

Actins ; metabolism ; Animals ; Carotid Arteries ; drug effects ; metabolism ; pathology ; Carotid Artery Injuries ; drug therapy ; genetics ; pathology ; Cyclic GMP ; blood ; Disease Models, Animal ; Gene Expression Regulation ; drug effects ; Hyperplasia ; Indole Alkaloids ; pharmacology ; therapeutic use ; Male ; Nitric Oxide ; blood ; Phosphorylation ; drug effects ; Proliferating Cell Nuclear Antigen ; metabolism ; Quinazolines ; pharmacology ; therapeutic use ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley ; Tunica Intima ; drug effects ; pathology

OBJECTIVETo investigate whether the methanol extract of Berberis amurensis Rupr. (BAR) augments penile erection using in vitro and in vivo experiments.

METHODSThe ex vivo study used corpus cavernosum strips prepared from adult male New Zealand White rabbits. In in vivo studies for intracavernous pressure (ICP), blood pressure, mean arterial pressure (MAP), and increase of peak ICP were continuously monitored during electrical stimulation of Sprague-Dawley rats.

RESULTSPreconstricted with phenylephrine (PE) in isolated endotheliumintact rabbit corus cavernosum, BAR relaxed penile smooth muscle in a dose-dependent manner, which was inhibited by pretreatment with NG-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, and H-[1,2,4]-oxadiazole-[4,3-α]-quinoxalin-1-one, a soluble guanylyl cclase inhibitor. BAR significantly relaxed penile smooth muscles dose-dependently in ex vivo, and this was inhibited by pretreatment with L-NAME H-[1,2,4]-oxadiazole-[4,3-α]-quinoxalin-1-one. BAR-induced relaxation was significantly attenuated by pretreatment with tetraethylammonium (TEA, P<0.01), a nonselective K channel blocker, 4-aminopyridine (4-AP, P<0.01), a voltage-dependent K channel blocker, and charybdotoxin (P<0.01), a large and intermediate conductance Ca sensitive-K channel blocker, respectively. BAR induced an increase in peak ICP, ICP/MAP ratio and area under the curve dose dependently.

CONCLUSIONBAR augments penile erection via the nitric oxide/cyclic guanosine monophosphate system and Ca sensitive-K (BK and IK) channels in the corpus cavernosum.

Animals ; Area Under Curve ; Berberis ; chemistry ; Blood Pressure ; drug effects ; Cyclic GMP ; metabolism ; Epoprostenol ; pharmacology ; In Vitro Techniques ; Indomethacin ; pharmacology ; Male ; Models, Biological ; Muscle Relaxation ; drug effects ; Muscle, Smooth ; drug effects ; physiology ; NG-Nitroarginine Methyl Ester ; pharmacology ; Nitric Oxide ; metabolism ; Penile Erection ; drug effects ; Phenylephrine ; pharmacology ; Plant Extracts ; pharmacology ; Potassium Channel Blockers ; pharmacology ; Potassium Channels ; metabolism ; Pressure ; Rabbits

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