In vitro anaphylactic reaction causes mast cell damage and histamine release from rat tissue. Histamine release is correlated with mast cell damage and both phenomena are simultaneously inhibited by various metabolic inhibitors, antipyretics, calcium lack and previous heating of the tissue at 45 degrees . The mast cell damage produced by antigen in sensitized rat tissues is morphologically similar to that caused by compound 48/80, both agents causing extrusion of granules. Mast cell damage and histamine release induced by antigen or by compound 48/80 are inhibited alike by several substances and conditions. It is suggested that in rats the histamine-releasing mechanism of the antigen-antibody reaction in anaphylaxis is very similar to that of compound 48/80.

Anaphylaxis↗

PubMed1960

The anti-anaphylactic and histamine-releasing properties of the antihistamines. Their effect on the mast cells.

IT HAS BEEN SHOWN THAT, DEPENDING UPON THEIR CONCENTRATION, ANTIHISTAMINES ACT IN THREE DIFFERENT WAYS: (a) by competitive inhibition of histamine as already known; (b) by destroying mast cells and releasing histamine; and (c) by preventing mast cell damage and histamine release in anaphylaxis. Furthermore, antihistamines potentiated mast cell damage and histamine release by compound 48/80, when acting on guinea-pig tissues, and inhibited these same phenomena when acting on rat tissues. It is concluded that the effect of antihistamines in anaphylaxis is possibly due both to their competitive inhibition of histamine on smooth muscle receptors and to their inhibition of mast cell damage and histamine release by antigen.

Anaphylaxis↗

PubMed1960

The inhibition of mast cell damage and histamine release in anaphylaxis by pyridine and diphosphopyridine nucleotidase inhibitors. Comparison with compound 48/80.

In rats and guinea-pigs both mast cell damage and histamine release in anaphylaxis were inhibited by pyridine, nicotinamide, diethylnicotinamide, nicotinic acid, isonicotinic acid and isonicotinic acid hydrazide, which are known to be inhibitors of diphosphopyridine nucleotidases. On the other hand these compounds potentiated histamine release and mast cell damage by compound 48/80 in guinea-pigs although inhibiting the same phenomena in rats. The relationship of these findings with the mechanism of histamine liberation in anaphylaxis is discussed.

Anaphylaxis↗

PubMed1959