Effects of Adenosine on Mast Cells

Abstract

Introduct1onStimulation of mast cells with appropriate antigen results in the rapid release of a large number of mediators of allergy from the cells.The cells possess cell surfa~e receptors for the Fe portion of IgE which serve to transmlt the signal of binding of an antigen by the lgE molecule to the interior of the cell.Since Studies of mast cells are complicated by important intraand inter-species differences. With1n a species~ there appear to be at least two groups of mast cells (review~d bY Enerback 1986).The first group i s the connective t1ssu~ mast cells, which is the most frequently studied type ~ mast cell s and i ncl udes, for exampl e the mast cel s obta i ned by peri tonea 1 1 avage.The seco~d group represents the ~ucosal mast cell s, which differ histologically, funct1onally and in their response to pharmacological agents from those of the first group. Blood basophils are, lik~ m~st cel_l s, der~ ved from bone marrow precursors, but. thei flnal d1fferent1ation in the blood rather than in t1ss~e~ ap~ears to result in yet another spectrum of propertleh ( ~ 1 tamura et a 1. 1983).Th i s heterogene 1 ty tagether wi t d1fferences b~tween species, and often between strains. 0~

Activation of pulmonary C fibres by adenosine in anaesthetized rats: role of adenosine A1 receptors

“…Polosa et al 1995); however, Ado by itself does not directly evoke the release of mediators from mast cells, although it potentiates the response triggered by other factors (e.g. Lohse, Maurer, Klotz & Schwabe, 1989). A role of bronchopulmonary C fibres in Ado-induced bronchoconstriction in humans (Crimi et al 1992) and in guinea-pigs (Manzini & Ballati, 1990) has also been suggested.…”

Selective Ligands for Rat A3 Adenosine Receptors: Structure-Activity Relationships of 1,3-Dialkylxanthine 7-Riboside Derivatives

“…Methyl 1,3-Di-ra-butylxanthine 7-y8-D-Ribofuronate (9). A solution of compound 20a (30 mg, 0.065 mmol) in 88% formic acid (3 mL) was stirred for 3 h at room temperature, and the solvent was removed by rotary evaporation.…”

“…In rat peritoneal mast cells, a component of enhancement of histamine release by adenosine also was reported to be insensitive to xanthines, suggesting the possible presence of A3 receptors. 9 Activation of A3 receptors is also associated with hypotensive,10 behavioral,11 and cardioprotective12 effects. Beaven et al7 have suggested that A3 antagonists may have potential as antiinflammatory agents acting via mast cells.…”

Molecular probes for the human adenosine receptors

“…4 , Table 4 ), SDS-PAGE analysis of rat brain membranes that were incubated with this covalent radioligand and UV-irradiated showed the appearance of a single protein band of ~ 35 kDa [ 129 ]. Interestingly, even though R -AHPIA is about 60-fold selective for the A 1 R, it is also a partial agonist at the A 2A R, and pretreatment with R -AHPIA reduced the stimulatory effect of NECA, indicating persistent binding of the ligand and subsequent reduced activation by a full agonist [ 131 ]. In the search for covalent antagonists, 4-azidophenethyl xanthine derivative [ 125 I]BW-A947U (Fig.…”