A biotinylated peptide, BP21, alleviates hypotension in anaphylactic mice

Platelet-activating factor (PAF) is known as an important mediator of anaphylaxis and, therefore, may possibly serve as a direct target for anti-anaphylactic drugs. We recently reported that a synthetic N-terminally biotinylated peptide, BP21, alleviates hypothermia and vascular hyperpermeability during anaphylactic reactions in a mouse model of anaphylaxis via the direct binding of a Tyr-Lys-Asp-Gly sequence in the peptide to PAF. In this study, we investigated the effect of BP21 on in vivo anaphylactic hypotension. Results showed that BP21 significantly inhibited anaphylactic hypotension in a dose-dependent manner, with peak severity being reached within 20 minutes. Adrenaline, which is the recommended first line treatment for anaphylactic patients, did not inhibit anaphylactic hypothermia. The combined administration of BP21 with adrenaline inhibited both hypotension and hypothermia, even at both low doses, more effectively compared with solo administration of BP21 or adrenaline. These results suggested that BP21 could potentially be a novel anti-anaphylactic agent for targeting PAF in vivo.