Broncho-Vaxom inhibits histamine release from rat mast cells induced by compound 48/80 and ionophore A23187

Broncho-Vaxom (BV) inhibited in dose-dependent manner the release of histamine from and degranulation of isolated rat peritoneal mast cells stimulated with compound 48/80 and the ionophore A23187. Inhibition persisted after removal of BV from the incubation medium before stimulation, but did not occur when bovine serum albumin (BSA) was used instead of BV. Binding of BV to mast cells was observed by electron microscopy on cells that had been incubated with colloidal-gold labelled BV. There was no significant difference between the binding of BV gold and BSA gold to the mast cells. Washing before fixation removed most of the BV gold from the cells. This study establishes BV as an in vitro histamine release inhibitor.     

维生素C对氟化钠和化合物48-80诱导大鼠肥大细胞释放组胺的影响

氟化钠(NaF)和化合物48-80均可诱发大鼠胸腔，腹腔肥大细胞释放组胺，前者依赖细胞外钙参与，后者与细胞外钙关系不大，二者的最适诱导浓度分别为10 mmol·L^-1和0.2 mg·L^-1. 维生素C可促进NaF诱导的组胺释放，但对化合物48-80所诱导的组胺释放无明显影响. 将肥大细胞置于37 ℃，2 h，NaF或化合物48-80诱导的组胺释放率均下降.预先加入维生素C 1 mmol·L^-1，此现象显著减弱.由此提示：NaF激发肥大细胞，增敏其对Ca²⁺分泌作用不是由自由基引发的，另一方面也不排除37 ℃长时间温育细胞产生自由基可能与降低细胞对NaF-Ca²⁺系统和化合物48-80的敏感性有关.     

Inhibitory effects of steroidal anesthetics on histamine release from rat mast cells stimulated by concanavalin A, compound 48/80 and A23187

1. Alphaxalone and alphadolone acetate were found to inhibit histamine release from rat mast cells induced by concanavalin A by blocking the calcium channels of the cells. 2. They also both inhibited the release induced by A23187, but only alphaxalone inhibited the release induced by compound 48/80. 3. It is concluded that the inhibitory effects of these compounds were not due to their anesthetic properties, but may have been due to their inhibition of steps of the release cascade that open calcium channels and subsequent steps.     

Dual effect of magnesium on compound 48/80-induced histamine secretion from rat peritoneal mast cells.

The effect of magnesium on the secretory response to compound 48/80 from rat peritoneal mast cells was studied. The decrease in secretion caused by calcium deprivation was enlarged by magnesium. Glucose partially counteracted the decrease caused by calcium deprivation but not the one caused by magnesium. The addition of calcium to the cells simultaneously with compound 48/80 completely restored the secretory response if magnesium was present. The response was only partially restored in a magnesium- and glucose-free medium, whereas it was almost completely restored if glucose was present. Magnesium had a considerable effect on the restoration of the secretory response of EGTA-treated cells, whereas the effect of glucose was minimal indicating that an effect on the energy metabolism was of minor importance. The secretory response could also be restored by an exposure of the cells to calcium prior to stimulation with compound 48/80. This was, however, only observed if magnesium was present and glucose had no effect. The influence of magnesium on the restoration of the secretory response may partly occur by an effect on the energy metabolism, partly by an effect on the stimulus-secretion coupling. We propose that insufficient supply of Mg2+ to the G-protein during activation by compound 48/80 might cause a suboptimal signal transduction.     

Compound 48/80 and substance P induced release of histamine and serotonin from rat peritoneal mast cells

The effect of substance P and compound 48/80 on histamine and serotonin release from not isolated and isolated mast cells have been compared in experiments in vitro. The response of not isolated and isolated mast cells were virtually identical. The release of both amines, in response to 48/80 and substance P, was dose-dependent. The percentage of histamine released by 48/80 was significantly higher than the percentage of serotonin, the difference being higher at lower concentrations of compound 48/80 after 15 min of incubation. Substance P also showed a tendency to higher efficiency for histamine than for serotonin release. In contrast to 48/80, the dose-response curves for histamine and serotonin release were parallel. These results support the view that the ratio between histamine and serotonin release depends on the liberator used. They also showed that this ratio can depend on the concentration of the agent inducing secretion. The results indicate that substance P as well as 48/80 act rather selectively as histamine liberators and that there is some difference in releasing properties of 48/80 and substance P.     

Inhibition of compound 48/80-mediated histamine release from isolated rat mast cells by oosponol-related compounds (4-acyl-isocoumarins).

Oosponol (4-hydroxymethylketone-8-hydroxyisocoumarin) is a metabolic product isolated from Oospora astringens which originated from house dust in a room of an asthmatic patient. The compound and the structurally related isocoumarins were studied to determine the inhibition of histamine release induced by compound 48/80 from isolated rat peritoneal mast cells. The released histamine was assayed by fluorometry. The compounds tested were not observed to release histamine. Some of 4-acyl-isocoumarins inhibited the histamine release at doses less than 10 micrometers, whereas the 3-acyl- and the 4-alkyl-compounds were not effective at doses over 100 microns. The pretreatment of mast cell with the compound for 15 min before the application of compound 48/80 was more effective than the simultaneous administration. The mode of inhibitory action of KIT-302, 4-(4'-carboxy-benzoyl)-isocoumarin, was non-competitive antagonism to compound 48/80 on the mast cells.     

Inhibitory activity of indolin-2-one derivatives on compound 48/80-induced histamine release from mast cells

Four alkaloids, previously identified in Isatis species, were tested for their inhibitory effect on histamine release. Whereas tryptanthrin, indirubin and deoxyvasicinone did not inhibit histamine release, the effect of indolin-2-one exceeded that of the mast cell stabilizing drug disodium chromoglycate.     

Comparison of histamine release induced by synthetic polycations with that by compound 48/80 from rat mast cells.

We compared the histamine release induced by polyethylenimines and polyallylamines with that induced by compound 48/80. Lidocaine inhibited the histamine release induced by polyethylenimine with a molecular weight of 600 (PEI6), but disodium cromoglycate did not. The histamine releases induced by all polyethylenimines and polyallylamines tested were inhibited by lidocaine, but not by disodium cromoglycate. Islet activating protein inhibited the histamine release induced by PEI6. Its effects on the release by other polyethylenimines and polyallylamines were less than that on PEI6. It is likely that the inhibition of G proteins by islet activating protein resulted in a decrease of the histamine release. This possibility was supported by the finding that guanyl-5'-(beta, gamma-imino) triphosphate enhanced the histamine release. An inhibitor of polyphosphoinositide phosphodiesterase, neomycin, did not affect the histamine releases induced by these polymers. The effect of PEI6 seemed to resemble that of compound 48/80. After pretreatment of mast cells with wheat germ agglutinin and with Limax flavus agglutinin, releases of histamine induced by PEI6 and compound 48/80 decreased, suggesting that the binding sites of PEI6 and compound 48/80 had sialic acid and/or N-acetyl glucosamine residues. The binding site for PEI6 seemed to especially overlap those of compound 48/80.     

维生素C对氟化钠和化合物48-80诱导大鼠肥大细胞释放组胺的影响

氟化钠（ＮａＦ）和化合物４８－８０均可诱发大鼠胸腔，腹腔肥大细胞释放组胺，前者依赖细胞外钙参与，后者与细胞外钙关系不大，二者的最适诱导浓度分别为１０ｍｍｏｌＬ－１和０．２ｍｇＬ－１．维生素Ｃ可促进ＮａＦ诱导的组胺释放，但对化合物４８－８０所诱导的组胺释放无明显影响．将肥大细胞置于３７℃，２ｈ，ＮａＦ或化合物４８－８０诱导的组胺释放率均下降．预先加入维生素Ｃ１ｍｍｏｌＬ－１，此现象显著减弱．由此提示：ＮａＦ激发肥大细胞，增敏其对Ｃａ２＋分泌作用不是由自由基引发的，另一方面也不排除３７℃长时间温育细胞产生自由基可能与降低细胞对ＮａＦ－Ｃａ２＋系统和化合物４８－８０的敏感性有关．     

The utilization of adenosine triphosphate in rat mast cells during histamine release induced by anaphylactic reaction and compound 48/80

Summary The ATP content of rat peritoneal mast cells has been studied in relation to histamine release induced by compound 48/80 and antigen-antibody (anaphylactic) reaction in vitro. When the ATP content of actively sensitized mast cells was reduced to different levels by oligomycin, a good correlation was obtained between the ATP levels and the amounts of histamine released by the anaphylactic reaction. A similar linear relation has previously been demonstrated between the ATP levels of mast cells and histamine release induced by compound 48/80. The ATP content of mast cells was also studied at different intervals after the exposure of the cells to antigen or compound 48/80. No significant change in the ATP content was observed in untreated mast cells during the short period when histamine release occurs. If, however, the mast cells were preincubated with oligomycin or 2-deoxyglucose to reduce the rate of ATP synthesis while a large part of the histamine release remained unaffected—a decrease in the ATP content could be demonstrated in close time relation to both anaphylactic and compound 48/80-induced histamine release. The observations indicate an increased utilization of ATP in mast cells during the release process.     

Early kinetics of Ca2+ fluxes and histamine release in rat mast cells stimulated with compound 48/80

The kinetics of Ca2+ uptake and efflux have been measured in rat peritoneal mast cells stimulated with compound 48/80 using rapid mixing and a silicone oil centrifugation technique. Responses at one-second time intervals were resolved beginning as early as three seconds after initial stimulation. The results clearly demonstrate that Ca2+ uptake occurs after the initiation of histamine release. Ca2+ efflux occurs simultaneously with histamine release. The implications of these findings are discussed and the technique is described.