Identification of acetylcholine, 5-hydroxy-tryptamine, histamine, and a new kinin in hornet venom (V. crabro)

A Fatal Effect of Hornet Venom on Rat-Brain Cortical Neurons

In a previous study, it was shown that the hornet venom or, more specifically, its venom sac extract (VSE) possesses deoxyribonuclease activity that exerts an effect both on insects as well as on mammals. We have now examined the effect of hornet VSE on primary culture of rat cortical neurons. Judging on the basis of our results, VSE induces a rapid cell death by a) permeabilizing the cell membrane, b) inducing DNA breaks, and c) cleaving the nuclear protein poly-ADP-ribose polymerase (PARP-1), thereby preventing DNA repair.

Biochemical and pharmacological characterization of the venom of the black scorpion Heterometrus spinifer

The sting of the black scorpion Heterometrus spinifer, which can cause intense localized pain, has not been reported to produce lethal cardiovascular complications, which are well known to result from scorpion envenomation as a consequence of a massive release of catecholamines. Therefore, we have undertaken a biochemical and pharmacological characterization of the venom of H. spinifer. Pharmacologically, the venom (0.125 microL/mL) produced a marked, reversible contracture in the chick biventer cervicis muscle that was blocked by d-tubocurarine (2 microM) but not by tetrodotoxin (5 microM) and omega-conotoxin GVIA (3 microM). The anticholinesterase neostigmine (1 microM) potentiated the contracture by 5.3-fold. An ultra-filtrate fraction of MW < 3000 (F3K) of the venom produced a similar contracture in the biventer muscle, whereas the retentate of MW > 3000 did not. In the rat anococcygeus muscle, the venom produced a contractile response that was partially (37.4 +/- 1.6%) blocked by atropine (5 microM); phentolamine (5 microM) blocked the remaining response. Tetrodotoxin (5 microM) did not block the contractile response of the venom on the anococcygeus muscle. Electrospray ionization-mass spectrometry/mass spectrometry confirmed the presence of high concentrations of acetylcholine (79.8 +/- 1.7 microM) and norepinephrine (146.7 +/- 19.8 microM) in H. spinifer venom, which can fully account for the observed cholinergic and adrenergic effects. In contrast to scorpion venoms that selectively target neuronal ion channels in mediating transmitter release, our data show that H. spinifer venom does not possess such activity, which likely explains the apparent lack of lethality of black scorpion envenomation.

Identification of noradrenaline in venom from the funnel-web spider Hololena curta

Venom from the funnel-web spider Hololena curta was added to the Krebs-Henseleit solution bathing isolated ring preparations of rat thoracic aorta, suspended in water-jacketed organ baths, for the purpose of tension recordings. Hololena curta venom at dilutions of 1:100,000 to 1:1000 caused a marked vasoconstriction, which was completely inhibited by the alpha 1 adrenoceptor antagonist prazosin (1 microm). The vasoconstriction appears to be due to the direct effects on alpha 1 adrenoceptors of a venom constituent, which we have identified using HPLC/ECD as the catecholamine, noradrenaline.

Cardiovascular haemodynamics of oriental hornet venom sac extract

The effects of hornet venom sac extract on the functioning of the cardiovascular system was assessed in dogs by concomitant examination of the following parameters: Systemic blood pressure, blood pressure and the dp/dt derivative of the left ventricle of the heart, heart rate, direct measurement of the left ventricular wall thickness, cardiac output, and body temperature. The effect of adult hornet venom sac extract on the canine cardiovascular system was rapid and led to a sharp drop in the systemic blood pressure, a similar drop in the pressure and dp/dt derivative in the left ventricle, to bradycardia, immediate thickening of the left ventricular wall and to an immediate rise in the cardiac output. As for the canine temperature, this dropped immediately following the administration of venom sac extract and remained at the new low level for at least 30 min. The smaller molecular weight components (less than 10 kilodalton) in venom sac extract have been found to be responsible for the immediate effects of venom sac extract on the cardiovascular system. On the other hand the high-molecular weight components exert more delayed effects which lead to a cumulative disturbance of cardiac function.

Hepatotoxicity induced by the Oriental hornet (Vespa orientalis) venom sac extract

Experiments were performed to investigate the nature of the in vitro and human liver damage exposed to hornets' acute or repeated stings. The hornet investigated is the one ubiquitous in Israel - Vespa orientalis. Experiments were performed in living cats and rats, after single or multiple exposures to venom-sac extracts (VSE) and in various doses. The injury was demonstrated by the increased levels of enzymes, bile acids and cholesterol in serum. Also measured was Beta-N-acetyl hexosaminidase (BNAH) which probably is the only biochemical indicator available of Kupffer-cell function. This, too, was found increased. Other experiments consisted of perfusion of the isolated, intact, rat liver in situ with measurements of enzyme leakage into perfusate and of bile flow. Another set of experiments involved the effects of VSE on in vitro monolayer tissue culture of rat embryos' livers. We examined damage to organelles and compared the damage produced by intact VSE with that produced by the venom sac extract after treatment by heat or dialysis. Light morphology, special stains, electron microscopy and morphometry were all performed. In the first set of experiments no shock was observed in cats and rats exposed to VSE. The increases in enzymes' activity in serum and liver perfusion fluid were significant. Histochemistry indicated decrease of hepatic glycogen and of cellular succinic dehydrogenase as well as hepatic fat infiltration and an increase of alkaline phosphatase activity in liver cells close to the bile capillaries.(ABSTRACT TRUNCATED AT 250 WORDS)

[Deaths following wasp stings]

Two cases of death have been reported following a wasp sting. In both cases an anaphylactic reaction after sensitization can be assumed (positive RAST result). In one case an expert witness report was required because of questions concerning insurance law (accident at work?) in addition to the cause of death. The stinger of the wasp was examined from the zoological aspect and is compared with that of the honeybee and hornet.

Anticholinesterase-like activity by oriental hornet (Vespa orientalis) venom and venom sac extract

Oriental hornet venom or venom sac extract produces pharmacological and toxicological effects typical of anticholinesterase agents. The effects produced in animals can be counteracted by atropine and heparin.

Mechanisms of the flare reaction in human skin

The diffuse area of arteriolar vasodilation surrounding a region of recently injured human skin (axon reflex flare) is dependent upon the integrity of nerve fibers with cell bodies located in dorsal root ganglia. Evidence is presented to indicate that a vasodilator peptide similar to a kinin, neurotensin, or substance P, is implicated in the chain of biochemical events responsible for the transient shift in vascular tonus observable as the flare reaction.