Enkephalins and anaphylactic shock: modulation and prevention of shock in the rat.
Wistar rats were sensitized for anaphylactic shock with ovalbumin and treated intraperitoneally with 10 injections of methionine-enkephalin and leucine-enkephalin (4 mg/kg of body weight). Both pentapeptides suppressed the development of systemic anaphylaxis after intravenous injection of a shocking dose of ovalbumin. Methionine-enkephalin completely protected the animals from fatal shock. The level of circulating IgE and precipitating anti-ovalbumin antibodies decreased in rats given 10 injections of enkephalins. Mast cell degranulation was significantly inhibited in these animals as observed at autopsy. A single intraperitoneal injection of 4 mg/kg body weight of methionine-enkephalin given 30 min before the challenge with shock-inducing dose of antigen was also effective, although to a lesser extent, in protecting animals from anaphylactic shock. One injection of leucine-enkephalin did not exhibit significant antishock activity. The results suggest that enkephalins, and methionine-enkephalin in particular, are potent modulators of the complex biochemical processes underlying the anaphylactic shock in the rat.
D000707:Anaphylaxis / Q000209:etiology / Q000517:prevention & control*; D000818:Animals; D004743:Enkephalin, Leucine / Q000276:immunology / Q000494:pharmacology; D004744:Enkephalin, Methionine / Q000276:immunology / Q000494:pharmacology; D004745:Enkephalins / Q000276:immunology / Q000494:pharmacology*; D007073:Immunoglobulin E / Q000378:metabolism; D008297:Male; D008407:Mast Cells / Q000276:immunology; D010047:Ovalbumin / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains
D004745:Enkephalins; D007073:Immunoglobulin E; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; D010047:Ovalbumin