Nitric Oxide Donor L-arginine Research Articles

Angiogenesis-associated pathways play critical roles in neonatal sepsis outcomes

Neonatal sepsis is a major cause of childhood mortality. Limited diagnostic tools and mechanistic insights have hampered our abilities to develop prophylactic or therapeutic interventions. Biomarkers in human neonatal sepsis have been repeatedly identified as associated with dysregulation of angiopoietin signaling and altered arachidonic acid metabolism. We here provide the mechanistic evidence in support of the relevance for these observations. Angiopoetin-1 (Ang-1), which promotes vascular integrity, was decreased in blood plasma of human and murine septic newborns. In preclinical models, administration of Ang-1 provided prophylactic protection from septic death. Arachidonic acid metabolism appears to be functionally connected to Ang-1 via reactive oxygen species (ROS) with a direct role of nitric oxide (NO). Strengthening this intersection via oral administration of arachidonic acid and/or the NO donor L-arginine provided prophylactic as well as therapeutic protection from septic death while also increasing plasma Ang-1 levels among septic newborns. Our data highlight that targeting angiogenesis-associated pathways with interventions that increase Ang-1 activity directly or indirectly through ROS/eNOS provide promising avenues to prevent and/or treat severe neonatal sepsis.

Nitric oxide nano-reactor DNMF/PLGA enables tumor vascular microenvironment and chemo-hyperthermia synergetic therapy

BackgroundBreast cancer ranks first among malignant tumors, of which triple-negative breast cancer (TNBC) is characterized by its highly invasive behavior and the worst prognosis. Timely diagnosis and precise treatment of TNBC are substantially challenging. Abnormal tumor vessels play a crucial role in TNBC progression and treatment. Nitric oxide (NO) regulates angiogenesis and maintains vascular homeostasis, while effective NO delivery can normalize the tumor vasculature. Accordingly, we have proposed here a tumor vascular microenvironment remodeling strategy based on NO-induced vessel normalization and extracellular matrix collagen degradation with multimodality imaging-guided nanoparticles against TNBC called DNMF/PLGA.ResultsNanoparticles were synthesized using a chemotherapeutic agent doxorubicin (DOX), a NO donor L-arginine (L-Arg), ultrasmall spinel ferrites (MnFe2O4), and a poly (lactic-co-glycolic acid) (PLGA) shell. Nanoparticle distribution in the tumor was accurately monitored in real-time through highly enhanced magnetic resonance imaging and photoacoustic imaging. Near-infrared irradiation of tumor cells revealed that MnFe2O4 catalyzes the production of a large amount of reactive oxygen species (ROS) from H2O2, resulting in a cascade catalysis of L-Arg to trigger NO production in the presence of ROS. In addition, DOX activates niacinamide adenine dinucleotide phosphate oxidase to generate and supply H2O2. The generated NO improves the vascular endothelial cell integrity and pericellular contractility to promote vessel normalization and induces the activation of endogenous matrix metalloproteinases (mainly MMP-1 and MMP-2) so as to promote extravascular collagen degradation, thereby providing an auxiliary mechanism for efficient nanoparticle delivery and DOX penetration. Moreover, the chemotherapeutic effect of DOX and the photothermal effect of MnFe2O4 served as a chemo-hyperthermia synergistic therapy against TNBC.ConclusionThe two therapeutic mechanisms, along with an auxiliary mechanism, were perfectly combined to enhance the therapeutic effects. Briefly, multimodality image-guided nanoparticles provide a reliable strategy for the potential application in the fight against TNBC.Graphical

Light-Triggered Nitric Oxide Nanogenerator with High l-Arginine Loading for Synergistic Photodynamic/Gas/Photothermal Therapy.

The development of nanomedicines that combine photothermal therapy (PTT) with photodynamic therapy (PDT) is considered promising for cancer treatment, but still faces the challenge of enhancing tumoricidal efficiency. Fortunately, apart from the well-acknowledged effect on direct tumor cell-killing, nitric oxide (NO) is also considered to be effective for the enhancement of both PTT and PDT. However, both the low loading efficiency of NO precursor and the short half-life time and diffusion distance of NO hamper the synergistic therapeutic efficacy of NO. Taking the aforementioned factors into account, a mitochondria-targeted nitric oxide nanogenerator, EArgFe@Ce6, is constructed to achieve high loading of the NO donor l-Arginine (l-Arg) for synergistic photodynamic/gas/photothermal therapy upon single 660nm light irradiation. The coordination of epigallocatechin gallate (EGCG) and ferric ions (Fe3+ ) provides EArgFe@Ce6 supreme photothermal capability to perform low-temperature PTT (mPTT). EGCG endows EArgFe@Ce6 with mitochondria-targeting capability and meanwhile favors hypoxia alleviation for enhanced PDT. The PDT-produced massive reactive oxygen species (ROS) further catalyzes l-Arg to generate a considerable amount of NO to perform gas therapy and sensitize both mPTT and PDT. In vitro and in vivo studies demonstrate that the synergistic photodynamic/gas/photothermal therapy triggered by single 660nm light irradiation is highly effective for tumor treatments.

A multifunctional nanocomposite coated with a BSA membrane for cascaded nitric oxide therapy

Gas therapy based on nitric oxide (NO) has emerged as a potential therapeutic approach for cancer, and in conjunction with multi-mode combination therapy, offers new possibilities for achieving significant hyperadditive effects. In this study, an integrated AI-MPDA@BSA nanocomposite for diagnosis and treatment was constructed for PDA based photoacoustic imaging (PAI) and cascade NO release. Natural NO donor L-arginine (L-Arg) and photosensitizer (PS) IR780 were loaded into mesoporous polydopamine (MPDA). Bovine serum albumin (BSA) was conjugated to the MPDA to increase the dispersibility and biocompatibility of the nanoparticles, as well as to serve as a gatekeeper controlling IR780 release from the MPDA pores. The AI-MPDA@BSA produced singlet oxygen (1O2) and converted it into NO through a chain reaction based on L-Arg, enabling a combination of photodynamic therapy and gas therapy. Moreover, due to the photothermal properties of MPDA, the AI-MPDA@BSA performed good photothermal conversion, which allowed photoacoustic imaging. As expected, both in vitro and in vivo studies have confirmed that the AI-MPDA@BSA nanoplatform has a significant inhibitory effect on cancer cells and tumors, and no apparent systemic toxicity or side effects were detected during the treatment period.

Doxorubicin hydrochloride and L-arginine co-loaded nanovesicle for drug resistance reversal stimulated by near-infrared light

Drug resistance is accountable for the inadequate outcome of chemotherapy in clinics. The newly emerging role of nitric oxide (NO) to conquer drug resistance has been recognized as a potential strategy. However, it remains a great challenge to realize targeted delivery as well as accurate release of NO at desired sites. Herein, we developed a PEGylated indocyanine green (mPEG-ICG) integrated nanovesicle system (PIDA) to simultaneously load doxorubicin hydrochloride (DOX⋅HCl) and the NO donor L-arginine (L-Arg), which can produce NO triggered by NIR light irradiation and exert multimodal therapy to sensitize drug-resistant cancers. Upon 808 nm irradiation, the NO released from PIDA led to a decrease in mitochondrial membrane potential, an increase in ROS and significant ATP depletion in K562/ADR cells, thus inhibiting cell growth and resolving the problem of drug resistance. Consequently, the in vivo experiment on K562/ADR-bearing nude mice indicated that PIDA nanovesicles achieved significant anticancer efficacy with a tumor inhibition rate of 80.8%. Above all, PIDA nanovesicles offer guidance for designing nanoplatforms for drug-resistant cancer treatment.

Fetal growth retardation as a complication of post-COVID endotheliitis: causes, consequences, ways of prevention

The risk of fetal intrauterine growth retardation (IUGR) is increased in women who have experienced acute infections, as well as in pregnant women with gynecological pathology and endocrine diseases. A woman’s lack of nutrition also makes a negative contribution to the development of IUGR. The frequency of IUGR in the population is very variable and depends on a number of reasons. In practically healthy pregnant women, IUGR is registered in 3–5% of cases, in case of complicated obstetric and gynecological diagnosis and complicated pregnancy – in 10–25%. Morphofunctional disorders in the chorion/placenta in pregnant women with COVID-19 on the background of post-covid endotheliitis are the main pathogenetic factor in the development of preeclampsia, ectopic pregnancy, antenatal fetal death, and impaired condition of the fetus and newborns. Sufficient saturation of the pregnant woman’s body with the nitric oxide donor L-arginine and L-carnitine (main cofactor of fatty acid metabolism in cells) with the improvement of microcirculation and the correction of hypovolemic disorders in the fetoplacental complex can be considered one of the real ways to prevent IUGR in women in the post-covid period.A review of the scientific literature on pathogenesis, diagnosis, impact on the life and health of a newborn with IUGR in women after COVID-19, as well as the possibilities of medical correction of placental dysfunction during pregnancy was performed.This analysis and our own clinical experience allow us to state the fact that after a coronavirus infection during pregnancy, one of the frequent and threatening for the further development of the child is the formation of placental dysfunction and IUGR. One of the ways to prevent these conditions is to saturate the woman’s body with the nitric oxide donor L-arginine from the stage of pre-gravid preparation, which will provide the opportunity for adequate angiogenesis and development of the embryo/fetus. In the case of additional risk factors, such as coronavirus disease, complex therapy blood (Rheosorbilact), in combination with a nitric oxide donor and L-carnitine as an endothelium-protective agent (Tivor-L).

Investigating the effect of the nitric oxide donor L-arginine on albendazole efficacy in Trichinella spiralis-induced myositis and myocarditis in mice

Investigating the effect of the nitric oxide donor L-arginine on albendazole efficacy in Trichinella spiralis-induced myositis and myocarditis in mice

Diabetes associated with hypertension exacerbated oxidative stress-mediated inflammation, apoptosis and autophagy leading to erectile dysfunction in rats.

Diabetes or hypertension contributes to erectile dysfunction (ED). We hypothesized that excess reactive oxygen species (ROS) production evoked by diabetes combined with hypertension may further suppress endothelial nitric oxide (NO) expression/activity and promote oxidative stress in the ED penis. Twenty-four adult male Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were divided into four groups: normal WKY, diabetic WKY, normal SHR and diabetic SHR. Intraperitoneal streptozotocin (65 mg/kg) was applied to induce type I diabetes. After 4-week diabetes and/or hypertension induction, we determined the intra-cavernous pressure (ICP) using electrical stimulation of cavernous nerves, intra-cavernosum NO amount using an electrochemical NO probe, and blood ROS using an ultrasensitive chemiluminescence-amplified analyzer. Western blot analysis and immunohistochemistry were used to explore the pathophysiologic mechanisms of inflammation, apoptosis and autophagy in the penis. A novel NO donor, CysaCysd Lu-5 (CCL5, (RCH2CH2S)(R'R"CHCH2S)Fe(NO)2, 1-4 µg), was intravenously administered to these ED rats for evaluating their ICP responses. In the baseline status, the lucigenin- and luminol-amplified blood ROS were significantly enhanced in the diabetic SHR rats vs normal WKY rats. Significantly decreased ICP, eNOS expression and NO amount were found in the normal SHR, diabetic WKY, and diabetic SHR vs normal WKY rats. Intravenous NO donor L-Arginine markedly increased ICP and NO amount, whereas eNOS inhibitor, Nω-Nitro-L-Arginine methyl ester hydrochloride depressed ICP in all four groups. Diabetes and/or hypertension alone increased fibrosis, proinflammatory NF-kB/ICAM-1 expression, mast cell numbers, CD68 expression and infiltration, Caspase 3-mediated apoptosis, Beclin-1/LC3-II-mediated autophagy and mild Nrf-2/HO-1 expression and depressed eNOS expression in the ED penis. The novel NO donor, CCL5, was more efficient than L-arginine to improve diabetes and/or hypertension-induced ED by the significant increase of ICP. Diabetes combined with hypertension synergistically exacerbated ED through enhanced oxidative stress, inflammation, apoptosis and autophagy and depressed eNOS activity and NO production.

An integrated approach to the treatment of pelvic pain associated with adenomyosis

Dysmenorrhoea and intermenstrual pelvic pain are the most common symptoms of clinical manifestations of adenomyosis, which significantly impair the quality of women’s life. Adequate and long-term pain correction and alternative therapeutic approaches became extremely important for patients with adenomyosis during the COVID-19 pandemic. Research objective: to examine the clinical efficacy of nitric oxide donor (L-arginine) in the complex treatment of pelvic pain syndrome associated with adenomyosis.Materials and methods. The study included 63 women diagnosed with adenomyosis. Patients were divided into 2 groups by simple randomization: I (D) group (n = 31) received dydrogesterone 30 mg from 5 to 25 days of the menstrual cycle, II (D+T) group (n = 32) in addition to dydrogesterone received a nitric oxide donor L-arginine (Тivortin) according to the scheme. Pelvic pain was assessed before treatment with a Visual Analogue Scale and a McGill Pain Questionnaire, and an assessment of the overall pain impact on women's well-being was based on the SF-36 Health Status Survey. The effectiveness of pelvic pain therapy was assessed after the first and third months of treatment, as well as three months after the end of therapy with the above methods.Results. Researchers achieved a therapeutic effect in the treatment of chronic pelvic pain in both study groups, but in group II (D + T) after 3 months of treatment there was a significant reduction in pelvic pain, while patients of the standard therapy group have prolonged progestogen intake. There was a further improvement in the clinical condition in group I (D) after 6 months of follow-up, as well as no recurrence of pain in group II (D + T).Conclusions. The results of study demonstrate a significant effect of Tivortin as part of complex therapy on the rate of achievement and duration of therapeutic effect in the treatment of pelvic pain associated with adenomyosis.

ICG/l-Arginine Encapsulated PLGA Nanoparticle-Thermosensitive Hydrogel Hybrid Delivery System for Cascade Cancer Photodynamic-NO Therapy with Promoted Collagen Depletion in Tumor Tissues.

Photodynamic therapy (PDT) is promising for clinical cancer therapy; however, the efficacy was limited as an individual treatment regimen. Here, an approach synergistically combining PDT and nitric oxide (NO) gas therapy along with destruction of the tumor extracellular matrix (ECM) was presented to eliminate cancer. Specifically, the NO donor l-arginine (l-Arg) and the photosensitizer indocyanine green (ICG) were co-encapsulated in poly(lactic-glycolic acid) (PLGA) nanoparticles and then loaded into the poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL) hydrogel to develop an injectable, thermosensitive dual drug delivery system (PLGA@ICG@l-Arg/Gel). Significantly, reactive oxygen species (ROS) produced by PLGA@ICG@l-Arg/Gel under near-infrared (NIR) light irradiation could not only result in the apoptosis of cancer cells but also oxidize l-Arg to generate NO, which could suppress the proliferation of cancer cells. Moreover, ROS could further oxidize NO to generate peroxynitrite anions (ONOO-). ONOO- could activate matrix metalloproteinases (MMPs), which notably degraded collagen in ECM so as to damage the tumor microenvironment. PLGA@ICG@l-Arg/Gel significantly increased the antitumor efficacy against highly malignant 4T1 tumors in mice. Taken together, PLGA@ICG@l-Arg/Gel is a multifunctional platform that provides a novel strategy for cancer treatment with cascade amplification of the ROS oxidation effect, which holds great potential in clinical translation.

α-Melanocyte-Stimulating Hormone Attenuates Neovascularization by Inducing Nitric Oxide Deficiency via MC-Rs/PKA/NF-κB Signaling.

α-melanocyte-stimulating hormone (α-MSH) has been characterized as a novel angiogenesis inhibitor. The homeostasis of nitric oxide (NO) plays an important role in neovascularization. However, it remains unclear whether α-MSH mitigates angiogenesis through modulation of NO and its signaling pathway. The present study elucidated the function and mechanism of NO signaling in α-MSH-induced angiogenesis inhibition using cultured human umbilical vein endothelial cells (HUVECs), rat aorta rings, and transgenic zebrafish. By Griess reagent assay, it was found α-MSH dose-dependently reduced the NO release in HUVECs. Immunoblotting and immunofluorescence analysis revealed α-MSH potently suppressed endothelial and inducible nitric oxide synthase (eNOS/iNOS) expression, which was accompanied with inhibition of nuclear factor kappa B (NF-κB) activities. Excessive supply of NO donor l-arginine reversed the α-MSH-induced angiogenesis inhibition in vitro and in vivo. By using antibody neutralization and RNA interference, it was delineated that melanocortin-1 receptor (MC1-R) and melanocortin-2 receptor (MC2-R) participated in α-MSH-induced inhibition of NO production and NF-κB/eNOS/iNOS signaling. This was supported by pharmaceutical inhibition of protein kinase A (PKA), the downstream effector of MC-Rs signaling, using H89 abolished the α-MSH-mediated suppression of NO release and eNOS/iNOS protein level. Therefore, α-MSH exerts anti-angiogenic function by perturbing NO bioavailability and eNOS/iNOS expression in endothelial cells.

PL - 032 Physiological triggers involved in reduced slow myosin expression in disused postural muscle

PL - 032 Physiological triggers involved in reduced slow myosin expression in disused postural muscle

Influence of nitrogen oxide donor on coagulation and fibrinolytic parameters in patients with hypertensiion and diabetes mellitus type 2

The article presents a study of plasma coagulation and level of fibrinolytic activity in patients with hypertension and type 2 diabetes when the nitric oxide donor L-arginine is added to the basic treatment. We have conducted an open prospective study including 109 patients. It was found significantly more substantial increasing of antithrombin III level (р<0,05), reliable decline of fibrinogen level (р<0,05), and also an increase of fibrinolytic activity (р<0,05) in the group which received L-arginine in addition to the basic treatment. It was proved that L-arginine which manifests its metabolic properties by changing the endothelial markers activity, could be recommended as an additional method of correction of plasma hemostasis and fibrinolytic activity in patients with hypertension and type 2 diabetes.

L-Arginine Pathway Metabolites Predict Need for Intra-operative Shunt During Carotid Endarterectomy

Asymmetric dimethylarginine (ADMA) inhibits nitric oxide (NO) synthesis and is a marker of atherosclerosis. This study examined the correlation between pre-operative l-arginine and ADMA concentration during carotid endarterectomy (CEA), and jugular lactate indicating anaerobic cerebral metabolism, jugular S100B reflecting blood-brain barrier integrity, and with factors of surgical intervention. The concentration of l-arginine, ADMA, and symmetric dimethylarginine was measured in blood taken under regional anaesthesia from the radial artery of 55 patients prior to CEA. Blood gas parameters, concentration of lactate, and S100B were also serially measured in blood taken from both the radial artery and the jugular bulb before and after carotid clamping, and after release of the clamp. To estimate anaerobic metabolism, the jugulo-arterial ratio of CO2 gap/oxygen extraction was calculated. Positive correlation was found between pre-operative ADMA levels and the ratio of jugulo-arterial CO2 gap/oxygen extraction during clamp and reperfusion (p=.005 and p=.01, respectively). An inverse correlation was found between the pre-operative l-arginine concentration and jugular lactate at each time point (both p=.002). The critical pre-operative level of l-arginine was determined by receiver operator curve analysis. If l-arginine was below the cutoff value of 35μmol/L, jugular S100B concentration was higher 24h post-operatively (p=.03), and jugular lactate levels were increased during reperfusion (p=.02). The median pre-operative concentration of l-arginine was lower in patients requiring an intra-operative shunt than in patients without need of shunt (median: 30.3μmol/L [interquartile range 24.4-34.4μmol/L] vs. 57.6μmol/L [interquartile range 42.3-74.5μmol/L]; p=.002). High pre-operative ADMA concentration predicts poor cerebral perfusion indicated by elevated jugulo-arterial CO2 gap/oxygen extraction. Low pre-operative l-arginine concentration predicts the need for a shunt. The inverse correlation between pre-operative l-arginine concentration and both jugular lactate and S100B during carotid clamping suggests a protective role of the NO donor l-arginine.

Apoptosis in Hemocytes Induces a Shift in Effector Mechanisms in the Drosophila Immune System and Leads to a Pro-Inflammatory State.

Apart from their role in cellular immunity via phagocytosis and encapsulation, Drosophila hemocytes release soluble factors such as antimicrobial peptides, and cytokines to induce humoral responses. In addition, they participate in coagulation and wounding, and in development. To assess their role during infection with entomopathogenic nematodes, we depleted plasmatocytes and crystal cells, the two classes of hemocytes present in naïve larvae by expressing proapoptotic proteins in order to produce hemocyte-free (Hml-apo, originally called Hemoless) larvae. Surprisingly, we found that Hml-apo larvae are still resistant to nematode infections. When further elucidating the immune status of Hml-apo larvae, we observe a shift in immune effector pathways including massive lamellocyte differentiation and induction of Toll- as well as repression of imd signaling. This leads to a pro-inflammatory state, characterized by the appearance of melanotic nodules in the hemolymph and to strong developmental defects including pupal lethality and leg defects in escapers. Further analysis suggests that most of the phenotypes we observe in Hml-apo larvae are alleviated by administration of antibiotics and by changing the food source indicating that they are mediated through the microbiota. Biochemical evidence identifies nitric oxide as a key phylogenetically conserved regulator in this process. Finally we show that the nitric oxide donor L-arginine similarly modifies the response against an early stage of tumor development in fly larvae.

Functional Role for Mouse Cerebellar NO/cGMP/K(ATP)Pathway in Ethanol-Induced Ataxia

We have previously shown that brain adenosine A1 receptors and nitric oxide (NO) play an important role in ethanol (EtOH)-induced cerebellar ataxia (EICA) through glutamate/NO/cGMP pathway. I now report possible modulation of EICA by the cerebellar NO/cGMP/K(ATP) pathway. EICA was evaluated by Rotorod in CD-1 male mice. All drugs (K(ATP) activators pinacidil, 0.05, 0.1, 0.5 nmol; minoxidil, 0.01, 0.1, 1.0 pmol; antagonists glipizide/glibenclamide, 0.01, 0.05, 0.1 nmol; NO donor l-arginine, 20 nmol; NOS inhibitors [iNOS] inhibitor L-NAME, 50 nmol; glutamate, 1.5 nmol; adenosine A1 receptor agonist N(6) -cyclohexyladenosine [CHA], 6, 12 pmol; antagonist DPCPX, 0.1 or 0.4 nmol) were given by direct intracerebellar microinfusion via stereotaxically implanted guide cannulas, except EtOH (2 g/kg, i.p.). Pinacidil and minoxidil dose-dependently accentuated, whereas glipizide and glibenclamide markedly attenuated EICA, indicating tonic participation of K(ATP) channels. Glipizide abolished the pinacidil potentiation of EICA, which confirmed both drugs acted via K(ATP) channels. A possible link between K(ATP) channels and glutamate/NO pathway was suggested when (i) CHA (12 pmol) totally abolished l-arginine-induced attenuation of EICA; (ii) L-NAME abolished l-arginine-induced attenuation of EICA associated with further increase in EICA; and (iii) the combined l-arginine and glutamate infusion virtually abolished EICA. Also, whereas CHA abolished glibenclamide-induced attenuation and potentiated pinacidil/minoxidil-induced accentuation of EICA, the effects of DPCPX were just the opposite to those of CHA. The results with CHA therefore suggest a functional link between K(ATP) and A1 receptors and between K(ATP) and glutamate/NO and as an extension may involve participation of NO/cGMP/K(ATP) pathway in EICA.

The Role of L‐Arginine and Inducible Nitric Oxide Synthase in Intestinal Permeability and Bacterial Translocation

Arginine has been shown to have several immunological and trophic properties in stressful diseases. Its metabolites, nitric oxide (NO) and polyamines, are related to arginine's effects. Thus, the aim of this study was to determine the effects of the NO donor L-arginine and the role of inducible NO synthase (iNOS) on intestinal permeability and bacterial translocation in a model of intestinal obstruction (IO) induced by a simple knot in the terminal ileum. Male C57BL6/J wild-type (WT) and iNOS knockout (iNOS-/-) mice were randomized into 6 groups: Sham and Sham-/- (standard chow), IO and IO-/- (standard chow +IO), and Arg and Arg-/- (standard chow supplemented with arginine + IO). After 7 days of treatment with standard or supplemented chows, IO was induced and intestinal permeability and bacterial translocation were evaluated. The small intestine and its contents were harvested for histopathological and morphometric analysis and the determination of polyamine concentration. Pretreatment with arginine maintained intestinal permeability (P > .05; Arg and Arg-/- groups vs Sham and Sham-/- groups), increased polyamine concentration in intestinal content (P < .05; Arg vs IO group), and decreased bacterial translocation in WT animals (Arg group vs IO and IO-/- groups). Absence of iNOS also presented a protective effect on permeability but not on bacterial translocation. Arginine supplementation and synthesis of NO by iNOS are important factors in decreasing bacterial translocation. However, when intestinal permeability was considered, NO had a detrimental role.

Multidrug strategies are effective in the treatment of severe experimental pancreatitis

Trypsinogen activation, oxygen radicals, cytokines, leukocyte infiltration, and pancreatic ischemia are important steps in the pathogenesis of necrotizing pancreatitis and associated systemic complications. Several drugs that inhibit those pathogenetic steps attenuated biochemical and histologic changes, while survival remained low. The aim of the present study was to evaluate the benefit of multidrug approaches compared to monotherapies on organ injury and survival in acute experimental pancreatitis in the rat model of retrograde bile injection combined with intravenous cerulein. Necrotizing pancreatitis was induced in rats. After a therapy-free interval of 6 hours, 10treatment regimens were evaluated: multidrug regimen 1, which contained the protease inhibitor gabexate mesilate, oxygen-free radical scavengers, nitric oxide donor L-arginine, a platelet-activating factor antagonist, and antibodies against intracellular adhesion molecule-1 (ICAM-1) dissolved in dextran, was compared to multidrug regimen 2 (dextran, acetylcysteine, L-arginine, and anti-ICAM-1), monotherapies of each of the drugs, and standard intravascular volume replacement. Both multidrug regimens significantly reduced pancreatic and systemic injury and microcirculatory disturbances compared to any of the monotherapies. Treatment with regimen 1 decreased 24-hour mortality to 0% and increased long-term survival to 85% (standard therapy, 70% and 15%, respectively). Multidrug regimen 2 was as effective as regimen 1. Treatment of acute necrotizing pancreatitis with multidrug regimens significantly decreases short-term mortality compared to monotherapies. Moreover, multidrug strategies are still effective after a wide therapeutic window. Key to this effective therapy is the inhibition of microcirculatory disturbances and of the systemic inflammatory response. The experimental superiority of the multidrug approach should be confirmed in a clinical trial.

Regulation of ciliary beat frequency by the nitric oxide signaling pathway in mouse nasal and tracheal epithelial cells

Objectives Our purpose was to investigate the role of the nitric oxide (NO) signaling pathway in the regulation of ciliary beat frequency (CBF) in mouse nasal and tracheal epithelial cells. Methods We studied the effects of the NO donor l-arginine (L-Arg) and specific inhibitors of the NO signaling pathway on CBF of both nasal and tracheal epithelial cells by using high-speed digital microscopy. We also examined eNOS, sGC β, PKG I and acetylated α tubulin expression in native mouse nasal and tracheal epithelium using immunohistochemical methods. Results L-Arg significantly increased CBF of cultured nasal and tracheal epithelial cells, and the effects were blocked by pretreatment with N G-nitro- l-arginine methyl ester (L-NAME), a NOS inhibitor, with LY-83583, a sGC inhibitor, or with KT-5823, a PKG inhibitor. Positive immunostaining for NO signaling molecules including eNOS, sGC β and PKG I was observed in either nasal or tracheal ciliated epithelium. Conclusion NO plays a role in regulating CBF of mouse respiratory epithelial cells via a eNOS–NO–sGC β–cGMP–PKG I pathway.

A novel electrochemical sensor based on nano-structured film electrode for monitoring nitric oxide in living tissues

A sensor exhibited high sensitivity and good selectivity for determination of nitric oxide (NO) was fabricated. The sensor was constructured by coating Nafion/multi-walled carbon nanoubes-chitosan-gold nanoparticles (Nafion/MWNTs-CS-AuNPs) film on glassy carbon electrode (GCE). Several key parameters affecting on the electrochemical response were optimized, such as the film thickness, applied potential and volume of Nafion. The sensor showed good linear relationship with the NO concentration in the range of 1.90 × 10 −8 to 5.40 × 10 −5 M and with the detection limit of 7.60 × 10 −9 M ( S/ N = 3). Finally, the sensor was successfully applied to the monitoring of NO release from living tissues, including mouse kidney, heart, spleen and liver (a slice). NO release at micro-molar level can be detected while the NO donor l-arginine ( l-Arg), nitroglycerin (GTN) and aspirin (ASA) was present. It was interestedly found that the capacities to induce NO generation were in the order of GTN > ASA > l-Arg when these stimulants were converted to the same concentration. In addition, the NO release is associated with the functional groups in these donors.