Auto-modulation of release of pharmacological mediators of immediate (type I) hypersensitivity. A review

The effects of long‐term treatment with sodium cromoglycate (SCG) and aminophylline on antigen‐induced bronchoconstriction have been studied in guinea‐pigs actively sensitized according to two different regimens (one producing IgE‐ and IgG‐like antibodies and the other producing exclusively IgG‐like antibodies). Treatment for three weeks with SCG (10 mg/kg) and aminophylline (10,30 or 60 mg/kg) led to a decreased bronchial response capacity which persisted even three days after treatment ceased. In this respect SCG was effective only in guinea‐pigs sensitized to produce at least partly IgE‐like antibodies; aminophylline was effective in guinea‐pigs sensitized to produce both IgE and/or IgG antibodies. The results in vivo with SCG were reflected in vitro by a reduced capacity of chopped lung tissue to release histamine at antigen challenge; lungs from animals treated with aminophylline did not show reduced histamine releasing capacity. Acute treatment with atropine was shown to reduce significantly the antigen‐induced bronchial contraction in guinea‐pigs sensitized to produce both IgE‐ and IgG‐antibodies. No effect of atropine was seen on an IgG‐mediated anaphylaxis. Increased reactivity to methacholine but not to histamine was seen in guinea‐pigs sensitized to produce both IgG‐ and IgE‐antibodies. Long‐term treatment with SCG did not affect this hyperreactivity to methacholine. Decreased reactivity to isoprenaline was found in isolated tracheae taken from guinea‐pigs sensitized to produce both IgE‐ and IgG‐like antibodies compared to unsensitized guinea‐pigs. Long‐term treatment with SCG, but not with aminophylline, reversed this decreased reactivity.

Section: Discussionmentioning

confidence: 99%

Antigen‐induced Bronchial Anaphylaxis in Actively Sensitized Guinea‐pigs: Effect of Long‐term Treatment With Sodium Cromoglycate and Aminophylline

Andersson

Bergstrand

1981

“…Theophylline has been shown to inhibit the release of pharmacological mediators of the immediate-type allergic reaction probably by increasing the mast cell cyclic AMP level (Kaliner & Austen, 1974;Holroyde, Burka & Eyre, 1977). Theophylline also blocks the potentiating effect of adenosine on mast cell histamine release (Marquardt, Parker & Sullivan, 1978).…”

Section: Discussionmentioning

confidence: 99%

Antigen‐induced Bronchial Anaphylaxis in Actively Sensitized Guinea‐pigs: Anti‐anaphylactic Effects of Sodium Cromoglycate and Aminophylline

Andersson

1980

The inhibitory effects of sodium cromoglycate (SCG) and aminophylline on antigen‐induced bronchial anaphylaxis in guinea‐pigs, actively sensitized according to different regimens, were examined. SCG (1 mg/kg administered intravenously) reduced the anaphylactic response in animals sensitized with 1 μg ovalbumin (OA) together with Al(OH)3 100 mg, and challenged at 14 and 40 days after sensitization. If higher doses of antigen (10 μg OA together with Al (OH)3 or 5 mg OA on day 0 plus 10 mg OA on day 2) were used for sensitization, the protective effect of SCG was found only in animals tested 14 days after sensitization. A low dose of aminophylline (0.3 mg/kg) that was without a direct bronchodilator effect when tested against a histamine (4 μg/kg)‐induced bronchospasm, produced an anti‐anaphylactic effect. The anti‐anaphylactic effect of aminophylline varied slightly with the way the animals were immunized and the time at which they were tested. It is concluded that bronchial anaphylaxis in guinea‐pigs sensitized with low doses of ovalbumin is a suitable model for the evaluation of anti‐anaphylactic properties of drugs.

“…In allergic pulmonary disease, numerous chemical agents (pharmacological mediators) are released from the lung tissue by specific antigen (Austen & Orange, 1976;Piper, 1977;Holroyde, Burka & Eyre, 1977); these mediators are responsible, in part, for the clinical symptoms in obstructive lung disease. Some actions of many of these mediators on various bovine blood vessels, including the pulmonary vasculature, have been described previously (Eyre, 1971;Burka & Eyre, 1974a;1977;Holroyde & Eyre, 1975 Aviado, 1962).…”

Section: Introductionmentioning

confidence: 99%

Preliminary Pharmacological Characterization of the Bovine Isolated Bronchial Artery Strip: A New Preparation

Arowolo

Eyre

1980

Self Cite

1This paper describes a preliminary pharmacological study of the isolated helical strip of bovine bronchial artery under isotonic conditions in Krebs-Henseleit solution. 2 The tissue contracted to histamine and 5-hydroxytryptamine (5-HT), actions which were selectively antagonized by mepyramine and methysergide respectively. Histamine was not inhibited by metiamide and 5-HT was not affected by morphine.3 Slow reacting substance of anaphylaxis (SRS-A), prostaglandin F2. (PGF2X) and PGE2 were spasmogenic, whereas PGE1 caused relaxation. No potential antagonists of these agents were tested. 4 Carbachol, at all concentrations, caused contractions of the bronchial artery which were completely, irreversibly blocked by atropine. 5 The spasmogenic action of phenylephrine was selectively blocked by dibenamine. Vessel strips which were partially contracted to histamine, relaxed to isoprenaline and salbutamol. The action of isoprenaline was inhibited similarly by either propranolol or practolol. The evidence therefore suggests the presence of functional a, I, and #2-adrenoceptors.