Search results for "Calcimycin"
showing 10 items of 24 documents
Nitric oxide production and endothelium-dependent vasorelaxation ameliorated by N1-methylnicotinamide in human blood vessels.
2012
N 1 -methylnicotinamide (MNA + ) has until recently been thought to be a biologically inactive product of nicotinamide metabolism in the pyridine nucleotides pathway. However, the latest observations imply that MNA + may exert antithrombotic and anti-inflammatory effects through direct action on the endothelium. We examined both in vivo and in vitro whether the compound might induce vasorelaxation in human blood vessels through the improvement of nitric oxide (NO) bioavailability and a reduction of oxidative stress mediated by endothelial NO synthase (eNOS) function. MNA + treatment (100 mg/m 2 orally) in healthy normocholesterolemic and hypercholesterolemic subjects increased the l-argini…
Acetylcholine via Muscarinic Receptors Inhibits Histamine Release from Human Isolated Bronchi
1997
Human bronchi were incubated in organ baths to measure histamine release. The calcium ionophore A23187 (10 mumol/L; 1 min) stimulated histamine release by 148 +/- 28% (n = 11) above the prestimulation level but was ineffective in epithelium-denuded bronchi. Neither bradykinin (0.1 mumol/L) nor compound 48/80 (10 micrograms/ml) triggered the release of histamine from epithelium-intact bronchi. Acetylcholine did not affect spontaneous histamine release (about 2 nmol/g x 5 min) but inhibited A23187-evoked histamine release in an atropine-sensitive manner. Already a concentration as low as 0.1 nmol/L acetylcholine was effective, the maximal inhibition (by 89%) occurred at 100 nmol/L, whereas a …
Tributyltin affects phagocytic activity of Ciona intestinalis hemocytes
1995
Organotin compounds have been used in marine anti-fouling paints as biocides. Because tunicates are vulnerable to these compounds in their natural habitats, we used Ciona intestinalis to establish an assay for phagocytosis in vitro of yeast by hemocytes after exposure to different concentrations (0.0015, 0.015, 0.15 and 1.5 microM) of four organotin compounds: tributyltin (TBT), triphenyltin (TPT), dibutyltin (DBT) and diphenyltin (DPT). To evaluate the phagocytic activity, we used a method based on fluorescence excitation of yeast pre-treated with eosin-Y. The percentage of phagocytosis decreased from 45.1 +/- 3.49 to 22.4 +/- 5.14 at 1.5 microM of TBT (P0.001); it was significantly reduce…
Platelet-endothelial interaction in tumor angiogenesis and microcirculation
2003
Activated platelets release angiogenic growth factors and have therefore been proposed to contribute to tumor angiogenesis within a potentially prothrombotic tumor microcirculation. The aim of the study was to investigate interactions of platelets with the angiogenic microvascular endothelium of highly vascularized solid tumors during growth and in response to endothelial stimulation in comparison with normal subcutaneous tissue. Experiments were performed in the dorsal skinfold chamber preparation of C57BL/6J mice bearing the Lewis lung carcinoma (LLC-1) or methylcholanthrene-induced fibrosarcoma (BFS-1). Fluorescently labeled rolling and adherent platelets, red blood cell velocity, and ve…
Inhibition of inflammatory responses by epitaondiol and other marine natural products
1995
The marine metabolites pacifenol, stypotriol triacetate and epitaondiol were tested for their effects on a number of inflammatory responses. Epitaondiol exhibited a potent topical anti-inflammatory activity related to inhibition of leukocyte accumulation. The other compounds showed a lower potency, similar to that of indomethacin. None of the compounds affected superoxide generation by human neutrophils but pacifenol effectively inhibited the degranulation response. This compound and epitaondiol decreased the release of eicosanoids with a higher potency on the cyclo-oxygenase pathway. Only epitaondiol inhibited human recombinant synovial phospholipase A2 activity in a concentration-dependen…
Long-chain fatty alcohols from pomace olive oil modulate the release of proinflammatory mediators
2009
Pomace olive oil is a by-product of olive oil extraction that is traditionally produced and consumed in Spain. The nonglyceride matter of this oil is a good source of interesting minor compounds, like long-chain fatty alcohols, which are present free or as part of waxes. In the present study, long-chain fatty alcohols were isolated from the nonglyceride fraction of pomace olive oil, and the composition was identified and quantified. The major components of long-chain fatty alcohols were tetracosanol, hexacosanol and octacosanol. We investigated the ability of long-chain fatty alcohols from pomace olive oil to inhibit the release of different proinflammatory mediators in vitro by cells invol…
Endogenous nitric oxide inhibits leukotriene B4 release from rat alveolar macrophages
1997
Effects of endogenous nitric oxide (NO) on the release of mediators of the lipoxygenase and cyclo-oxygenase pathway from rat alveolar macrophages were studied. Alveolar macrophages, freshly isolated or after 18-h culture, were incubated in (amino acid-free) Krebs medium and labelled with [3H]arachidonic acid. The release of [3H]leukotriene B4 and [3H]prostanoids (separated by high performance liquid chromatography) was determined. A 23187 was used as stimulus, as rising intracellular Ca2+ activates directly the phospholipase A2 and lipoxygenase pathway. A 23187 (10 microM) enhanced [3H]leukotriene B4 release from freshly prepared alveolar macrophages about 65-fold, but only 5- to 6-fold fro…
Anti-Inflammatory Triterpenes from Pistacia terebinthus Galls
2002
From the galls of Pistacia terebinthus we obtained an extract that proved to be effective against chronic and acute inflammation. Now we report on the isolation and identification of three triterpenes: two tirucallane-type lanostanoids and one oleanane, which we have identified as masticadienonic acid (1), masticadienolic acid (2), and morolic acid (3), respectively. All of them showed effectiveness on the mouse ear inflammation induced by repeated applications of 12-O-tetradecanoylphorbol 13-acetate and on the phospholipase A2-induced foot paw edema. The pharmacological activity of the compounds was ratified by a histological study of the ear samples. In addition, they inhibited leukotrien…
Calcium overload increases oxidative stress in old rat gastrocnemius muscle
2005
International audience; In order to challenge in vivo muscle Ca2+ homeostasis and analyze consequences on mitochondrial H2O2 release (MHR) and sarcopenia, we injected Ca2+ ionophore A23187 (200 µg/kg, ip) in adult and old rats and measured gastrocnemius mass and mitochondrial Ca2+ content (MCC) using radioactive Ca2+ 48 h after injection. In a second experiment performed in old rats, we measured isocitrate dehydrogenase (ICDH) activity as an index of MCC, MHR, mitochondrial respiration, citrate synthase, COX and antioxydant enzyme activities 24 h after a 150 µg/kg injection. In adult rats, muscle mass and MCC were unchanged by A23187. In old rats, MCC increased 24 h after injection as refle…
Selectivity of Neutrophil 5-Lipoxygenase and Cyclo-oxygenase Inhibition by an Anti-inflammatory Flavonoid Glycoside and Related Aglycone Flavonoids
1988
Abstract A newly described plant-derived flavonoid, hypolaetin-8-glucoside, which has anti-inflammatory and gastroprotective actions in-vivo, and its corresponding aglycone, hypolaetin, have been compared with 14 other flavonoids for inhibition of eicosanoid generation via the 5-lipoxygenase and cyclo-oxygenase pathways in elicited rat peritoneal leukocytes stimulated with calcium ionophore. Comparable results for the inhibitory profiles of the compounds were obtained using either radioimmunoassay of released eicosanoids or radio-TLC of metabolites formed from labelled arachidonate, but there were differences in absolute potency of the inhibitors. Hypolaetin-8-glucoside was a weak but selec…