Bronchodilatory, antitussive and anti-inflammatory effect of morin in the setting of experimentally induced allergic asthma

OBJECTIVE

Using an experimental model of allergic asthma, we evaluated the anti-asthmatic potential of polyphenol flavonol derivate morin after either acute or long-term treatment of male OVA-sensitised guinea pigs.

METHODS

The following methods were used in experiments: the in-vitro tracheal smooth muscle contraction induced by histamine; the changes in specific airway resistance (sRaw) to histamine and the sensitivity of a chemically induced cough reflex both via an in-vivo method; the serum and BALF concentrations' analysis of the inflammatory cytokines interleukin IL-4, IL-5, IL-13; and lung tissue infiltration by eosinophils and mastocytes.

KEY FINDINGS

Our data show that acute morin (30 mg/kg) and chronic 21-day morin (30 mg/kg/day) administration had a comparable antitussive efficiency with opioid antitussive codeine. Acute morin bronchodilatory activity defined by in-vivo sRaw decline did not reach SABA salbutamol effect. However, bronchodilatory efficiency of morin after long-term administration was by 34% higher as effect of LABA salmeterol. The 21-day morin treatment of OVA-sensitised guinea pigs reduced the serum, BALF levels of IL-4 and IL-13, lung tissue eosinophil and mastocyte infiltration comparable with corticosteroid budesonide.

CONCLUSIONS

In summary, morin represents very rational target for additional studies as potential substance for control as well as prevention of asthma inflammation and symptoms.

Experimental model of allergic asthma

The aim of the study was to prepare and evaluate the experimental model of allergic asthma. Changes in chough reflex, bronchoconstriction and the degree of inflammation were studied in ovalbumin (OVA) sensitized guinea pigs after 0, 7, 14, 21 days of exposure. The cough reflex was induced by citric acid inhalation in conscious animals in a double chamber body plethysmograph. Tracheal smooth muscle reactivity was assessed by examining the in vitro response to histamine (H) (10(-8)-10(-3) mol/l) and in vivo to H nebulization (10(-6) mol/l). BALF levels of IL-4, IL-5 and the eosinophil count were used as parameters of airway inflammation. After 7 days of OVA sensitization, there was an increase in tracheal smooth muscle contractility in vitro to cumulative concentration of H and an increase in cough parameters. After 14 days of OVA sensitization, there was a further increase in tracheal smooth muscle contractility to H, an increase in airway resistance, and a small increase in cough parameters. After 21 day of OVA sensitization, cough parameters were significantly reduced, airway resistance after H inhalation was increased, and there were significant increases in IL-4, IL-5, and eosinophils in BALF. In conclusion, progress in asthmatic inflammation during 21-day OVA sensitization caused a gradual increase in inflammatory mediators, a decline in cough reflex, and enhanced bronchoconstriction. This experimental model of allergic asthma can be used for pharmacological modulations of defense reflexes and inflammation.

Utero-relaxant effect of PDE4-selective inhibitor alone and in simultaneous administration with beta2-mimetic on oxytocin-induced contractions in pregnant myometrium

BACKGROUND

The objective of the study was to observe the effect of rolipram, the prototype phosphodiesterase 4 selective inhibitor, on oxytocin-induced contractions of human term myometrial strips, and compare the effect with salbutamol, beta(2)-adrenergic agonist, in single and the simultaneous application.

METHODS

Human myometrium was obtained from pregnant women in term that had a term delivery by the caesarian section. Myometrial strips were excised from the lower uterine segment and placed into an organ-bath with Krebs-Henseleit buffer. The mean peak amplitude of contraction (mN) of the myometrial smooth muscle to the doses of oxytocin (10(-6) mmol/L(-1)) with subsequent single administration of rolipram (10(-4) mmol/L(-1)), salbutamol (10(-4) mmol/L(1)) and simultaneous administration of rolipram and salbutamol (both 10(-4) mmol/L(-1)), was used as a parameter of myometrial reactivity.

RESULTS

Rolipram alone decreased the oxytocin-induced contractile amplitude to 47.98%, single salbutamol application resulted in amplitudinal decrease to 56.07%, and the combination of both compounds in their simultaneous administration resulted in the decrease of oxytocin-induced contractile amplitude to 29.1%.

CONCLUSION

Our data are consistent with previous studies of the enhanced efficiency of the beta(2)-adrenergic agonist, when administered together with the phosphodiesterase 4-inhibitor. Moreover we have shown that rolipram alone has a more profound effect on oxytocin-induced contractions than salbutamol alone.

CRAC ion channels and airway defense reflexes in experimental allergic inflammation

Calcium release-activated calcium channels (CRAC) play unambiguous role in secretory functions of mast cells, T cells, and eosinophils. Less knowledge exists about the role of CRAC, widely distributed in airway smooth muscle (ASM) cells, in airway contractility. The presented study seeks to determine the possible participation of CRAC in ASM-based inflammatory airway disorders in guinea pigs. The acute and long-term administration (14 days) of the CRAC antagonist 3-fluoropyridine-4-carboxylic acid was used to examine the ASM contractility and associated reflexes in the guinea pig model of allergic airway inflammation by the following methods: (i) evaluation of specific airway resistance in vivo; (ii) evaluation of the contractile response of isolated ASM strips in vitro; and (iii) citric acid-induced cough reflex; (iv) measurement of exhaled NO levels (E(NO)). Allergic airway inflammation was induced by repetitive exposure of guinea pigs to ovalbumin (10(-6) M). The CRAC antagonist administered in a single dose to guinea pigs with confirmed allergic inflammation significantly reduced the cough response and the airway resistance, which corresponded with the findings in vitro. Long-term application of the CRAC antagonist had more strongly expressed effects. The results confirm the role of CRAC in the pathophysiology of experimental animal asthma and have a potential meaning for anti-asthma therapy.

Effects of flavin7 on allergen induced hyperreactivity of airways

Some studies have suggested that the polyphenolic compounds might reduce the occurrence of asthma symptoms. The aim of our experiments was to evaluate the effects of 21 days of the flavonoid Flavin7 administration on experimentally induced airway inflammation in ovalbumin-sensitized guinea pigs. We assessed tracheal smooth muscle reactivity by an in vitro muscle-strip method; changes in airway resistance by an in vivo plethysmographic method; histological picture of tracheal tissue; and the levels of interleukin 4 (IL-4), and interleukin 5 (IL-5) in bronchoalveolar lavage fluid (BALF). Histological investigation of tracheal tissue and the concentrations of the inflammatory cytokines IL-4 and IL-5 in BALF were used as indices of airway inflammation. Administration of Flavin7 caused a significant decrease of specific airway resistance after histamine nebulization and a decline in tracheal smooth muscle contraction amplitude in response to bronchoconstricting mediators. Flavin7 minimized the degree of inflammation estimated on the basis of eosinophil calculation and IL-4 and IL-5 concentrations. In conclusion, administration of Flavin7 showed bronchodilating and anti-inflammatory effects on allergen-induced airway inflammation.

Red wine polyphenolic compounds inhibit tracheal smooth muscle contraction during allergen-induced hyperreactivity of the airways

The aims of the study were to investigate the short and long-term effects of Provinol (red wine polyphenolic compounds) on tracheal smooth muscle reactivity using an in-vitro model of ovalbumin-induced airway inflammation in guinea-pig trachea, and to evaluate the role of nitric oxide (NO) in the bronchodilatory effect of Provinol.

The amplitude of tracheal smooth muscle contraction in response to mediators of bronchoconstriction —histamine (10 nM-1 mM), acetylcholine (10 nM-1 mM) and to allergen (ovalbumin 10−5-10−3 g mL−1) was used as a parameter of tracheal smooth muscle reactivity. To test the short-term effects of Provinol, isolated tracheal strips were pre-treated for 30 min with Provinol (10−4mg mL−1) alone or in combination with Nω-nitro-L-arginine methyl ester (L-NAME; 10−6mol L−1). To test the long-term effects of Provinol, isolated tracheal strips were prepared from guinea pigs that had been treated for 14 days with Provinol (20mg kg−1 per day) alone or in combination with L-NAME (40 mg kg−1 per day).

Incubation of tracheal smooth muscle with Provinol decreased the amplitude of contraction in response to ovalbumin, histamine and acetylcholine. The non-selective NO synthase inhibitor L-NAME partially abolished the effect of Provinol on acetylcholine and ovalbumin-induced but not histamine-induced bronchoconstriction. A similar profile was observed after 14 days' oral administration of Provinol.

In conclusion, Provinol inhibited the allergen- and spasmogen-induced contraction of tracheal smooth muscle in ovalbumin-sensitized guinea pigs via a mechanism that was mediated at least partially through the metabolism of NO.

Pharmacodynamic evaluation of RP3128, a novel and potent CRAC channel inhibitor in guinea pig models of allergic asthma

The increase in intracellular Ca(2+) levels through the activation of Ca(2+) release-activated Ca(2+) (CRAC) channels is essential for mediating a wide scale of immune cell responses. Emerging evidence indicates an involvement of abnormal CRAC channel activity in human diseases such as certain types of immunodeficiency, autoimmunity and allergic disorders. This objective of this study was to evaluate the therapeutic potency of a novel CRAC channel inhibitor, RP3128, in experimental models of allergic asthma using guinea pigs. Ovalbumin-induced allergic airway inflammation was determined upon acute and long-term (14 days) oral administration of RP3128. In vivo changes in specific airways resistance (sRaw) and amplitude of isometric contraction (mN) of ASM (in vitro) were estimated to evaluate bronchodilatory effect upon acute and long-term administration of RP3128 or salbutamol. Exhaled nitric oxide (eNO), immunohistochemical and histological analysis of cellular infiltration in airways tissue, and levels of cytokines in plasma as well as bronchoalveolar lavage fluid (BALF), were determined using Bio-Plex® 200 System (BIO-RAD, USA). Ciliary beat frequency (CBF, in Hz) was estimated using a high-speed video camera and LabVIEW™ Software. Additionally, the impact of RP3128 and budesonide on mucociliary clearance was determined. Acute and long-term administration of RP3128 resulted in significant bronchodilation. Long-term administration of RP3128 exceeded the bronchodilatory effect of salbutamol and significantly decreased eNO and cytokine levels in plasma and BALF, which together with histological and immunohistochemical analysis validated its anti-inflammatory effect compared to budesonide. Data demonstrate the therapeutic potential of RP3128 in respiratory diseases causally associated with allergic inflammation.

Involvement of calcium regulating ion channels in contractility of human isolated urinary bladder

This study specified the role of several key calcium-operating ion channels in contraction/relaxation of human detrusor muscle as possible target for overactive bladder (OAB) treatment. Detrusor samples, obtained from 18 males (average age 61.5 ± 5.9 years), were investigated by organ tissue bath method with following agents: diltiazem for L-type voltage-gated calcium channels; 3-fluropyridine-4-carboxylic acid (FPCA) for Orai-STIM channels; SKF 96365-hydrochloride for transient receptor potential (TRP) channels, T-type channels and Orai-STIM channels; 2- aminoethoxydiphenyl borate (2-APB) for inositol-triphosphate receptors (IP3Rs) and Orai-STIM channels. Oxybutynin and mirabegron were tested under the same conditions as controls. Mirabegron, 2-APB and FPCA exhibited the best suppressive effect on carbachol-induced detrusor contractility. As expressed by area under the contractile curve (AUCC), 2-APB, FPCA and mirabegron have similar AUCC: 1.79, 1.73, 1.73. The highest AUCC was 3.64 for diltiazem+SKF, followed by 3.21 for diltiazem, 3.16 for SKF and 2.94 for oxybutynin. The lowest median amplitude and contraction variability is for 2-APB followed by mirabegron and FPCA. There were significant differences between: 2-APB/FPCA vs.: ditiazem, diltiazem+SKF and SKF. Summary of results suggested the principal role of IP3Rs, Orai-STIM coupling and large-conductance calcium-activated potassium channels in detrusor contraction and pointed on Orai-STIM channels as possible targets for OAB pharmacotherapy.

The anti-asthmatic potential of Rho-kinase inhibitor hydroxyfasudil in the model of experimentally induced allergic airway inflammation

OBJECTIVE

This experimental study evaluated the anti-asthmatic potential of the Rho-kinase inhibitor hydroxyfasudil in the settings of allergen-induced allergen-induced experimental asthma.

METHODS

Chronic allergic airway inflammation was caused by 28 days-sensitisation of guinea pigs with ovalbumin (OVA). Hydroxyfasudil was administered intraperitoneally in two doses for the last two weeks (1 mg/kg b.w.; 10 mg/kg b.w.). The degree of allergic inflammation was determined based on concentrations of inflammatory Th2 cytokines (IL-4, IL-13), Th1 cytokines (TNF-α and IFN-γ) in the lung homogenate and leukocyte count in the bronchoalveolar lavage fluid (BALF). The markers of remodelling and fibrosis, the growth factors (TGF-β1, EGF), EGF receptor, collagen type III and V were estimated in lung homogenate. The changes in specific airway resistance (sRaw) were used as an in vivo bronchial hyperreactivity parameter.

RESULTS

Hydroxyfasudil administration at both doses significantly reduced sRaw after a week of therapy. We observed a decline of IL-13, TNF-α and IFN-γ in lung homogenate and a lower presence of lymphocytes in BALF after 14 days of hydroxyfasudil administration at both tested doses. Hydroxyfasudil 14 days-treatment at both doses effectively reduced the concentrations of TGF-β1, EGF receptors, collagen type III and V in BALF and modulated EGF levels.

CONCLUSIONS

These findings indicate that RhoA/Rho-kinase is involved in the pathophysiology of allergic airway inflammation and suggest that Rho-kinase inhibitor hydroxyfasudil has therapeutic potential for asthma management.

Airway Defense Control Mediated via Voltage-Gated Sodium Channels

Expression of voltage-gated sodium channels (Nav) takes place in the airways and the role of Nav1.7 and Nav1.8 in the control of airway's defense reflexes has been confirmed. The activation of Nav channels is crucial for cough initiation and airway smooth muscle reactivity, but it is unknown whether these channels regulate ciliary beating. This study evaluated the involvement of Nav1.7 and Nav1.8 channels in the airway defense mechanisms using their pharmacological blockers in healthy guinea pigs and in the experimental allergic asthma model. Asthma was modeled by ovalbumin sensitization over a period of 21 days. Blockade of Nav1.7 channels significantly decreased airway smooth muscle reactivity in vivo, the number of cough efforts, and the cilia beat frequency in healthy animals. In the allergic asthma model, blockade of Nav1.8 efficiently relieved symptoms of asthma, without adversely affecting cilia beat frequency. The study demonstrates that Nav1.8 channel antagonism has a potential to alleviate cough and bronchial hyperreactivity in asthma.

The Role of Ion Channels to Regulate Airway Ciliary Beat Frequency During Allergic Inflammation

Overproduction of mucus is a hallmark of asthma. The aim of this study was to identify potentially effective therapies for removing excess mucus. The role of voltage-gated (Kir 6.1, KCa 1.1) and store-operated ion channels (SOC, CRAC) in respiratory cilia, relating to the tracheal ciliary beat frequency (CBF), was compared under the physiological and allergic airway conditions. Ex vivo experiments were designed to test the local effects of Kir 6.1, KCa 1.1 and CRAC ion channel modulators in a concentration-dependent manner on the CBF. Cilia, obtained with the brushing method, were monitored by a high-speed video camera and analyzed with ciliary analysis software. In natural conditions, a Kir 6.1 opener accelerated CBF, while CRAC blocker slowed it in a concentration-dependent manner. In allergic inflammation, the effect of Kir 6.1 opener was insignificant, with a tendency to decrease CBF. A cilio-inhibitory effect of a CRAC blocker, while gently reduced by allergic inflammation, remained significant. A KCa 1.1 opener turned out to significantly enhance the CBF under the allergic OVA-sensitized conditions. We conclude that optimally attuned concentration of KCa 1.1 openers or special types of bimodal SOC channel blockers, potentially given by inhalation, might benefit asthma.

The effect of long-term administered CRAC channels blocker on the functions of respiratory epithelium in guinea pig allergic asthma model

Previously, therapeutic potency of CRAC channels blocker was evidenced as a significant decrease in airway smooth muscle hyperreactivity, antitussive and anti-inflammatory effects. The major role of the respiratory epithelium in asthma pathogenesis was highlighted only recently and CRAC channels were proposed as the most significant route of Ca2+ entry into epithelial cells. The aim of the study was to analyse the impact of long-term administered CRAC channels blocker on airway epithelium, e.g. cytokine production and ciliary beat frequency (CBF) using an animal model of allergic asthma. Ovalbumin-induced allergic airway inflammation of guinea pigs was followed by long-term (14 days lasted) therapy by CRAC blocker (3-fluoropyridine-4-carboxylic acid, FPCA). The influence of long-term therapy on cytokines (IL-4, IL-5 and IL-13) in BALF and in plasma, immunohistochemical staining of pulmonary tissue (c-Fos positivity) and CBF in vitro were used for analysis. Decrease in cytokine levels and in c-Fos positivity confirmed an anti-inflammatory effect of long-term administered FPCA. Cytokine levels in BALF and distribution of c-Fos positivity suggested that FPCA was a more potent inhibitor of respiratory epithelium secretory functions than budesonide. FPCA and budesonide reduced CBF only insignificantly. All findings supported CRAC channels as promising target in the new strategy of antiasthmatic treatment.

Orai1 protein expression and the role of calcium release-activated calcium channels in the contraction of human term-pregnant and non-pregnant myometrium

AIM

This experimental in vitro study examined differences in the expression and activity of calcium release-activated calcium (CRAC) channels of human term-pregnant and non-pregnant myometrium.

MATERIAL AND METHODS

The tissue samples were obtained from term-pregnant myometrium in labor of women undergoing cesarean section and from non-pregnant myometrium of women undergoing total hysterectomy due to uterine myoma. The expression of Orai1 protein, a pore-forming subunit of CRAC channels, in human myometrium was examined using immunohistochemistry. CRAC channel involvement in the amplitude and frequency of myometrial contractions was evaluated in vitro using a tissue bath method with a CRAC ion channel blocker 3-fluropyridine-4-carboxylic acid (FPCA).

RESULTS

Decreased Orai1 expression was observed in human term-pregnant laboring myometrium compared with non-pregnant myometrium. However, the initial oxytocin-induced contraction of myometrium was significantly suppressed at different doses of FPCA in both non-pregnant human isolated myometrium and non-pregnant myometrium. The frequency of contractions was the most significantly reduced at the lowest dose of FPCA in non-pregnant myometrium and remained suppressed at all doses of FPCA in term-pregnant myometrium. Salbutamol was shown as more effective in suppression of amplitude in term-pregnant isolated myometrium.

CONCLUSION

Our results provide the first information about the changes in the Orai1 protein expression and activity of human myometrial CRAC channels in term-pregnant laboring myometrium.

Pharmacodynamic evaluation of dihydroxyflavone derivate chrysin in a guinea pig model of allergic asthma

OBJECTIVE

This experimental study evaluated the anti-asthmatic capacity of the dihydroxyflavone chrysin in the settings of ovalbumin (OVA)-induced allergic inflammation.

METHODS

The parameters that were used to assess the anti-asthmatic activity of chrysin included the specific airway resistance to histamine, the sensitivity to a chemically induced cough and the activity of chrysin on the ciliary beat frequency (CBF) of the respiratory epithelium. The anti-inflammatory potential was confirmed by the measurement of cytokine concentrations Th2 (IL-4, IL-5 and IL-13), Th1 (Granulocyte-macrophage colony-stimulating factor [GM-CSF], INF-γ and IL-12), leucocyte count in the bronchoalveolar lavage fluid (BALF) and growth factor TBF-β1 in lung homogenate.

KEY FINDINGS

Chronic administration of chrysin (30 mg/kg/day for 21 days) to OVA-sensitised guinea pigs showed bronchodilatory activity comparable to that of long-acting β 2 receptors agonist (LABA) salmeterol. Chrysin revealed antitussive efficiency but was not able to abolish the negative effect of OVA on CBF. Chrysin managed to ameliorate the progression of chronic airway inflammation by decreasing the count of eosinophils, lymphocytes and basophils, IL-5, L-13, GM-CSF, INF-γ in BALF, and TGF-β1 in lung homogenate.

CONCLUSIONS

The acquired results support the complex anti-asthmatic profile of chrysin. The flavone may represent an attractive compound for further studies concerning the prevention or treatment of asthma.

Development of Sensitive and High-Throughput Liquid Chromatography-Tandem Mass Spectrometry Method for Quantification of Haloperidol in Human Plasma with Phospholipid Removal Pretreatment

Haloperidol, butyrophenone derivative, is a typical antipsychotic drug used in the treatment of schizophrenia, manic phase of bipolar disorder, and acute psychomotor agitations. According to the recent guidelines for therapeutic drug monitoring, it is strongly recommended to measure plasma level during the therapy with haloperidol. The objective of this study was to develop and validate a simple liquid chromatography-tandem mass spectrometry-based method to quantitate haloperidol in human plasma. After one-step extraction procedure using OSTROTM plate, gradient elution on Acquity UPLC BEH C18 (50 ×2.1mm, 1.7μm) column over 3.2 min was performed. The detection was conducted on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring mode in positive ionization mode with transitions at m/z 376.29 → 165.14 and m/z 380.28 → 169.17 for haloperidol and haloperidol-d4 (used as an internal standard), respectively. The method was fully validated to cover wide concentration range of 0.05-80 ng/mL in human plasma and meets the criteria for the selectivity, linearity and lower limit of detection, precision and accuracy, matrix effect, extraction recovery, carryover, dilution integrity and stability. The extraction recovery was nearly 100%, and no significant matrix effects were observed. Therefore, the method is applicable to routine therapeutic drug monitoring in patients' plasma.

The role of cytokines in degenerative spine disorders

Background: Degenerative spine disorders (DSD) are the most frequent reason of morbidity in adults. Commonly DSD includes degenerative disorders of intervertebral discs (IVDs), spinal stenosis and degenerative spondylolisthesis (SL). There is increasing evidence about significant role of cytokines in DSD pathogenesis, symptomathology and progression, but their protective levels remain still unknown.

Material and Methods: The aim of presented study was to provide quantitative and qualitative analysis of cytokine, chemokine and growth factors levels in individual parts of IVDs - annulus fibrosus (AF) and nucleus pulposus (NP) - separately and in facet joints (FJ) subchondral bone of patients with DSD and in controls - healthy subjects during a multiorgan procurement procedure. Bio-Plex® assay was used to measure concentrations of 27 different cytokines in tissue of patients with DSD. Their concentrations in tissues of healthy subjects during a multiorgan procurement procedure represented protective levels.

Results: The Bio-Plex® assay revealed significant differences between the patients suffered from degenerated and herniated IVDs and from lumbar SL and controls in cytokines, chemokines and growth factor profiles suggested that pro-inflammatory changes of both NP and AF were dominated in herniated IVDs, whereas the same tissue of lumbar SL patients exhibited much more complex changes in cytokine levels suggested o only ongoing inflammation (IL-6, IL-8, MCP-1, TNF-α), abut also antiinflammatory processes (IL-ra, IL-10) or connective tissue remodeling (PDGF-bb, IL-17, VEGF). The different mediators were found elevated in lumbar SL samples of subchondral FJ bone. These also confirmed ongoing inflammation, accelerated bone resorption and formation and increased fibroblasts activity in FJ bone.

Conclusion: The study supported the significant involvement of several cytokines, chemokines and growth factors in the pathogenesis of DSD. These cytokines should represent future potential targets for new biological treatment able to slow DSD progression as well as factor determining prognosis of DSD.

WITHDRAWN: The efficiency of polyphenolic compounds on allergen induced hyperreactivity of the airways

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.bionut.2010.09.002. The duplicate article has therefore been withdrawn.

Age-dependent changes of airway obstruction parameters

The study was aimed at the assessment of the physiological range of phi and Tme/Te indices in children of up to 24 months of age, as based on noncalibrated respiratory inductive plethysmography performed in the supine position. We also examined the dependence of these indices on children's age and sex. The study was carried out in 127 healthy children. The results of the study indicate a significant decrease of phi in children aged 7-24 months in comparison with children of up to 6 months of age (P<0.001). Similarly, values of Tme/Te were found significantly higher in the group of older children (P<0.05). We did not find any appreciable sex differences in both measured parameters. The results of this study suggest that the Tme/Te index might be more stable, less age-dependent parameter of the Respitrace measurement than the phase angle j, but further research and analysis to achieve a correct verdict are warranted.

Therapeutic approach to a child with acute respiratory distress syndrome: a report of two cases

The course of a respiratory disorder in a child may end up in respiratory failure. There are also acute non-respiratory diseases which have a great influence on the respiratory functions and often lead to the acute lung injury and sometimes to the acute respiratory distress syndrome (ARDS). A feature of respiratory function deterioration is changed in the surfactant system. We often see inhibition of its synthesis or damage to its structure. Therapy of children suffering from ARDS should be complex and rapid. Despite many recently published studies explaining the principle of this disorder, the mortality of ARDS is still very high (30-50%). There are several studies documenting successful administration of exogenous surfactant as part of a complex combined therapy of patients with ARDS, which leads to decreased mortality, improved oxygenation, and decreased need for aggressive artificial pulmonary ventilation. The authors of this article present their own experience with administration of exogenous surfactant in therapy of children with ARDS.

Analysis of HIF-1α expression and genetic polymorphisms in human clear cell renal cell carcinoma

Introduction: Clear cell renal cell carcinoma (ccRCC) is mostly diagnosed incidentally and has relatively high recurrence rates. Alterations in VHL/HIF and mTOR pathways are commonly present in ccRCC. The present study attempted to identify potential diagnostic markers at the biochemical and molecular level. Methods: In total, 54 subjects (36 patients with ccRCC and 18 cancer-free controls) were enrolled. ELISA was used to measure the levels of HIF-1α in the tumor and healthy kidney tissue. The association between five selected SNPs (rs779805, rs11549465, rs2057482, rs2295080 and rs701848) located in genes of pathologically relevant pathways (VHL/HIF and mTOR) and the risk of ccRCC in the Slovak cohort was studied using real-time PCR. Results: Significant differences in HIF-1α tissue levels were observed between the tumor and healthy kidney tissue (p < 0.001). In the majority (69%) of cases, the levels of HIF-1α were higher in the kidney than in the tumor. Furthermore, the concentration of HIF-1α in the tumor showed a significant positive correlation with CCL3 and IL-1β (p (R2) 0.007 (0.47); p (R2) 0.011 (0.38). No relationship between intratumoral levels of HIF-1α and clinical tumor characteristics was observed. Rs11549465, rs2057482 in the HIF1A gene did not correlate with the expression of HIF-1α either in the tumor or in the normal kidney. None of the selected SNPs has influenced the susceptibility to ccRCC. Conclusion: More research is neccesary to elucidate the role of HIF-1α in the pathogenesis of ccRCC and the association between selected SNPs and susceptibility to this cancer.

The role of potassium ion channels in cough and other reflexes of the airways

In this study we investigated whether openers of potassium channels, K+ATP--pinacidil and BK+Ca--NS1619, modulate cough reflex and airway smooth muscle (ASM) reactivity in in vivo and in vitro conditions in guinea pigs. The cough reflex was induced by 0.3 M citric acid aerosol given for 3 min during which time a total number of coughs was counted. ASM reactivity in vivo was expressed as the values of specific airway resistance calculated by Pennock. Changes in ASM reactivity in vitro were tested by a tissue bath method. We found that both openers of potassium channels inhibit the citric acid-induced cough. ASM reactivity in vivo was significantly abolished by pinacidil and NS1619, which corresponded with the results of in vitro measurements. Pretreatment by selective blockers, K+ATP--glibenclamide and BK+Ca-tetraethylammonium prevented the above mentioned effects. The results indicate an important role of K+ATP and BK+Ca ion channels in defense reflexes of airways.

The influence of animal species on the relationship between ATP-sensitive potassium ion channels and defense reflexes of the airways

BACKGROUND

The ATP-sensitive potassium ion channels (K+ATP) are widely expressed on airway sensory nerves that mediate cough and other protective reflexes; dependent on airways smooth muscles (ASM) reactivity.

OBJECTIVE

The study was conducted to determine the involvement of K+ATP in airway sensory nerves activity of different animal species.

METHODS

In this study we have evaluated the cough reflex inhibiting potential and modulation of ASM reactivity in vitro, by K+ATP opener-pinacidil in guinea pig and cats. The cough in guinea pig was induced by administration, in cats by mechanical stimulation of the airways. ASM reactivity was tested by organ tissue both method of 0.3 M citric acid aerosol at 3 min interval.

RESULTS

1) Pinacidil inhibits cough reflex in guinea pigs which was antagonized when pre-treated with K+ATP blocker glibenclamide. 2) Pinacidil exhibited antitussive activity in cats comparable to codeine and was noticeably higher than dropropizine effects. 3) ASM reactivity was significantly abolished by pinacidil and almost completely antagonized by glibenclamide in guinea pigs. 4) Pinacidil significantly attenuated ASM contraction in cats only in highest concentrations of contractile mediators.

CONCLUSION

K+ATP may be involved in mechanisms of cough reflex, likewise in antitussive activity of several more agents and also on defence reflexes dependent on ASM reactivity in different animal species such as guinea pigs and cats (Fig. 8, Ref. 20). Full Text (Free, PDF) www.bmj.sk.

Antitussive activity of Althaea officinalis L. polysaccharide rhamnogalacturonan and its changes in guinea pigs with ovalbumine-induced airways inflammation

AIM

The presented studies were aimed on experimental confirmation of Althaea officinalis polysaccharide rhamnogalacturonan antitussive effect and its changes in conditions of allergic inflammation.

METHODS

We have tested whether rhamnogalacturonan inhibits cough reflex and modulates airways reactivity of guinea pigs in vivo. The cough in guinea pigs was induced by 0.3 M citric acid (CA) aerosol for 3 min interval, in which total number of cough efforts (sudden enhancement of expiratory flow accompanied by cough movement and sound) was counted. Specific airway resistance and its changes induced by citric acid aerosol were considered as an indicator of the in vivo reactivity changes.

RESULTS

1) Althaea officinalis polysaccharide rhamnogalacturonan dose- dependently inhibits cough reflex in unsensitized guinea pigs. Simultaneously, plant polysaccharide shortened the duration of antitussive effect when it was been tested in inflammatory conditions. 2) Rhamnogalacturonan did not influence airways reactivity in vivo conditions expressed as specific resistance values neither sensitized nor unsensitized groups of animals. 3) The antitussive activity of codeine (dose 10 mg.kg(-1) b.w. orally) tested under the same condition was comparable to higher dose of rhamnogalacturonan in unsensitized animals. 4) The characteristic cellular pattern of allergic airways inflammation was confirmed by histopathological investigations.

CONCLUSION

Rhamnogalacturonan isolated from Althaea officinalis mucilage possesses very high cough suppressive effect in guinea pigs test system, which is shortened in conditions of experimentally induced airways allergic inflammation (Tab. 1, Fig. 4, Ref. 25). Full Text in free PDF www.bmj.sk.