Mastoparan, a peptide toxin from wasp venom, is a nonspecific secretagogue. We show here that mastoparan increases the GTPase activity and the rate of nucleotide binding of several purified GTP-binding regulatory proteins (G proteins) whose function is to couple cell-surface receptors to intracellular mediators. Mastoparan accelerated guanosine-5'-(3-O-thiotriphosphate binding and consequent G ...

Hymenoptera allergens are the main triggers for anaphylaxis in susceptible dogs and humans. venom specific immunotherapy (VIT), only disease-modifying treatment, has potential to prevent future life-threatening reactions human patients. Prospective clinical data on VIT efficacy currently lacking. Therefore, aim of this study was show that is not safe but also efficacious preventing allergic Hym...

Cytosolic free calcium, [Ca(2+)](i), measured in individual prothoracic gland cells of Manduca sexta with Fura-2 was increased by prothoracicotropic hormone, PTTH, and by mastoparan, a wasp venom peptide, activating G proteins. The effect on [Ca(2+)](i) of mastoparan and of PTTH was inhibited by cadmium and the antagonist of T-type calcium channels, amiloride, and not influenced by the L-type c...

BACKGROUND Even though allergies are an important health issue, wide manufacturer-dependent differences in the detected amounts of allergen-specific IgE (sIgE) have repeatedly been found. These discrepancies hinder diagnostics and research into clinically significant cutoff points for life-threatening symptoms. METHODS To evaluate whether the reported differences have led to changes in diagno...

Phosphatidylcholine, labeled by two fluorescent fatty acids, was fed to cultured plant cells (Petrosilenum crispum, L.; VBI-0, Nicotiana benthiana, L.) and fluorescent diacylglycerol (DAG) was the major metabolite. When a glycoprotein elicitor, derived from Phytophthora sojae, was applied to the parsley cells and the small protein cryptogein from Phytophthora cryptogea was applied to the tobacc...

Two different stages should be considered in the management of bee and wasp stings to the eye. The first is the acute stage of activity of the specific insect venom on the structures the eye. The reaction of the eye to the particular insult is considered here in regard to the anterior and posterior segments of the eye. The second stage is that of the retained intraocular foreign body, the inert...

Venoms frequently co-opt host immune responses, so study of their mode of action can provide insight into novel inflammatory pathways. Using bee and wasp venom responses as a model system, we investigated whether venoms contain CD1-presented antigens. Here, we show that venoms activate human T cells via CD1a proteins. Whereas CD1 proteins typically present lipids, chromatographic separation of ...

Human victims of a massive number of stings have been steadily increasing since the invasion of Africanized honey bees (Apis mellifera) to the United States in 1990. Multiple honey bee stings may result in venom toxicity, leading to renal failure and even death. Here we tested the efficacy of methyl anthranilate as a honey bee repellent during a massive defensive response by Africanized honey b...

The purpose of our investigations was to evaluate the supposed beneficial effects of gamma-linolenic (GLA) and docosahexaenoic acid (DHA) in a canine mastocytoma cell line (C2) as a model for canine atopic dermatitis. Cells were cultured in a basic medium (DEH) and in DEH supplemented with 14.3 microM GLA (DEH-GLA) or 14.3 microM DHA (DEH-DHA) for 8 days. Chymase and tryptase activity, as well ...

Pompilidotoxins (PMTXs), derived from the venom of solitary wasp has been known to facilitate synaptic transmission in the lobster neuromuscular junction, and a recent further study from rat trigeminal neurons revealed that the toxin slows Na+ channel inactivation without modifying activation process. Here we report that beta-PMTX modifies rat brain type II Na+ channel alpha-subunit (rBII) expr...