Sulfur dioxide in the caudal ventrolateral medulla reduces blood pressure and heart rate in rats via the glutamate receptor and NOS/cGMP signal pathways / 生理学报

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 NG-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.

Influence of acupuncture combined with rehabilitation therapy on limb motor function and serum cAMP and cGMP in patients with hemiplegia of cerebral ischemic stroke / 中国针灸

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.

Effects of NO/cGMP inhibitors in a rat model of anaphylactoid shock

Anaphylactic shock can be defined as an acute syndrome, and it is the most severe clinical manifestation of allergic diseases. Anaphylactoid reactions are similar to anaphylactic events but differ in the pathophysiological mechanism. Nitric oxide (NO) inhibitors during anaphylaxis suggest that NO might decrease the signs and symptoms of anaphylaxis but exacerbate associated vasodilation. Therefore, blocking the effects of NO on vascular smooth muscle by inhibiting the guanylate cyclase (GC) would be a reasonable strategy. This study aimed to investigate the effects of NO/cGMP pathway inhibitors methylene blue (MB), Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME), and indigo carmine (IC) in shock induced by compound 48/80 (C48/80) in rats. The effect was assessed by invasive blood pressure measurement. Shock was initiated by C48/80 intravenous bolus injection 5 min before (prophylactic) or after (treatment) the administration of the inhibitors MB (3 mg/kg), L-NAME (1 mg/kg), and IC (3 mg/kg). Of the groups that received drugs as prophylaxis for shock, only the IC group did not present the final systolic blood pressure (SBP) better than the C48/80 group. Regarding shock treatment with the drugs tested, all groups had the final SBP similar to the C48/80group. Altogether, our results suggested that inhibition of GC and NO synthase in NO production pathway was not sufficient to revert hypotension or significantly improve survival.

Glabridin alleviates ischemia/reperfusion-induced functional failure of smooth muscle of rat ileum by upregulating the cAMP / Glabridin alivia la falla funcional inducida por isquemia/reperfusión del músculo liso de ileum murino regulando el incremento de cAMP

Despite the development of modern medicine, alternative medicine, which has not lost its timeliness, remains attractive for the treatment of various diseases. Glabridin, a major flavonoid of Glycyrrhiza glabra, is known for its antioxidant and anti-inflammatory activity. The aim of this study was: 1) to determine the possible protective role of glabridin against ischemia/reperfusion (I/R) injury of the intestine; 2) to evaluate the in vitrocontractile responses of ileum smooth muscles to acetylcholine after an intestinal I/R; and 3) to explain the underlying molecular mechanism of its effect. Rats were assigned to groups of six rats each; 1) I/R, 2) gla10, 3) gla20, 4) gla40, 5) N5-[imino(nitroamino)methyl]-L-ornithine, methyl ester monohydrochloride (L-NAME)+gla40, and 6) Sham group. The healing effect of glabridin was abolished by L-NAME. Glabridin did not cause contractility of the smooth muscles to acetylcholine-induced contractile responses in intestinal I/R. Yet, it increased to spontaneous basal activity.

A pesar del desarrollo de la medicina moderna, la medicina alternativa, sin perder su vigencia, sigue siendo atractiva para el tratamiento de varias enfermedades. Glabradina, el flavonoide mayoritario de Glycyrrhiza glabra, es conocido por su actividad antioxidante y antiinflamatoria. Los propósitos de este estudio fueron: 1) Determinar el posible rol protector de glabradina ante daños intestinales por isquemia/reperfusion (I/R) 2) Evaluar in vitrolas respuestas de contracción de los músculos lisos del ileum ante acetilcolina después de I/R intestinal; y 3) Explicar el mecanismo molecular subyacente de este efecto. Se asignaron grupos de seis ratas: 1) I/R, 2) gla10, 3) gla20, 4) gla40, 5) N5-[imino(nitroamino)metil]-L-ornithina, metil ester monohidrochloruro (L-NAME)+gla40, y 6) Grupo testigo. El efecto curativo de glabridina fue abolido por L-NAME. Glabridina no causó contracción en el músculo liso como respuesta acetilcolina-inducida I/R. Además, incrementa la actividad basal expontánea.

A influência do oxido nítrico na fisiopatologia da neuropatia glaucomatosa / The influence of nitric oxide on the pathophysiology of glaucomatous neuropathy

Resumo O oxido nitrico (NO) é um fator relaxante derivado do endotélio e um potente vasodilatador que impacta em vários sistemas em todo o corpo. Estudos comprovam que o fluxo sanguíneo ocular basal é regulado pelo NO, sendo um importante regulador da homeostase, especialmente dentro dos tecidos uveais. A disfunção da produção de NO seria associado ao glaucoma através da alteração da perfusão da cabeça do nervo óptico associado ao aumento da pressão intraocular devido um sistema de drenagem trabecular deficiente. O NO tornou-se uma molécula atraente para o tratamento do glaucoma devido a possibilidade de modulação da drenagem trabecular, abaixando a pressão intraocular e ação neuroprotetora melhorando a perfusão sanguínea na cabeça do nervo óptico.

Abstract Nitric Oxide (NO) is a relaxing endothelium-derived factor and a potent vasodilator that impacts various systems throughout the body. Proven studies of basal ocular blood flow are regulated by NO, being an important regulator of homeostasis, especially within the uveal tissues. The dysfunction of the production associated with glaucoma due to alteration of the optic nerve head associated to the increase of the intraocular pressure by a deficient trabecular meshwork. NO became an attractive molecule for the treatment of glaucoma due to a modulation of the trabecular meshwork, lowering the neuroprotective intra and ocular pressure for a blood surgery in the head of the optic nerve.

Effect and Mechanism of Phosphodiesterase Inhibitors on Trabecular Outflow

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). 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.

Roles of signaling molecules in biofilm formation / 生物工程学报

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.

Vasorelaxant activity of Euphorbia furcillata Kunth mainly by activation of NO/cGMP pathway and calcium channel blockade / Actividad vasorrelajante de Euphorbia furcillata Kunth principalmente por activación de la vía NO/GMPc y bloqueo de canales de calcio]

The aim of current study was to determinate ex vivo and chromatographic fingerprint by HPLC of four extracts of Euphorbia furcillata K. Ethyl acetate extract of Euphorbia furcillata (EaEEf) was the most effective and potent extract (Emax=98.69±1.24%) and its effect was partially endothelium-dependent. Functional vasorelaxant mechanism of action of EaEEf was determinate, EaEEf showed efficient relaxation of KCl [80 mM]-induced contraction and norepinephrine and CaCl2 contraction curves showed diminution of maximal contraction in the presence of EAEEf and EaEEf-relaxation curve was shifted to the right in the presence of L-NAME (nitric oxide synthase inhibitor) and ODQ (guanylate cyclase inhibitor). Chromatographic fingerprints analysis suggests presence of diterpenoid such as abietane, tigliane, and ingenane skeletons. Our experiments suggest the EaEEf vasorelaxant activity could be attributed to diterpenoid molecules whose mechanism involves nitric oxide production and calcium channel blockade.

Se determinó el efecto vasorrelajante ex vivo y los perfiles cromatográficos mediante HPLC de cuatro extractos de Euphorbia furcillata K.. El extracto de acetato de etilo de E. furcillata (EaEEf) fue el más eficaz y potente en la contracción inducida por norepinefrina (Emax=98.69±1.24%) y el efecto fue parcialmente dependiente del endotelio vascular. Se determinó el mecanismo de acción vasorrelajante para EaEEf, este mostró ser eficaz sobre la contracción inducida por KCl [80 mM] y la curva de contracción en respuesta a norepinefrina y CaCl2 en presencia de EaEEf mostró disminución en la contracción máxima, mientras que la curva de relajación de EaEEf en presencia de L-NAME (inhibidor de óxido nítrico sintasa) y ODQ (inhibidor de guanilato ciclasa) se desplazó hacia la derecha. El análisis cromatográfico de EaEEf sugiere la presencia de moléculas diterpenoides como abietano, tigliano y esqueletos de ingenano. Nuestros resultados sugieren que el efecto vasorrelajante de EaEEf podría atribuirse a moléculas diterpenoides, cuyo mecanismo de acción involucra la producción de óxido nítrico y bloqueo de canales de calcio.

Beneficial Effect of Berberis amurensis Rupr. on Penile Erection / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate whether the methanol extract of Berberis amurensis Rupr. (BAR) augments penile erection using in vitro and in vivo experiments.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>Preconstricted 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.</p><p><b>CONCLUSION</b>BAR augments penile erection via the nitric oxide/cyclic guanosine monophosphate system and Ca sensitive-K (BK and IK) channels in the corpus cavernosum.</p>

Rutaecarpine Inhibits Intimal Hyperplasia in A Balloon-Injured Rat Artery Model / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the effect and potential mechanisms of rutaecarpine (Rut) in a rat artery balloon-injury model.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>Compared 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).</p><p><b>CONCLUSION</b>Rut could inhibit the balloon injury-induced carotid intimal hyperplasia in rats, possibly mediated by promotion of NO production and inhibiting ERK2 signal transduction pathways.</p>