Hyperglycemia produced by Vespa orientalis venom sac extract

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)

Multiple hornet (Vespa orientalis) stings with fatal outcome in a child

A case of multiple hornet stings is described with a rapidly fatal course due to the combination of massive haemolysis, coagulopathy, rhabdomyolysis, hyperkalaemia, acute renal failure, encephalopathy, hepatotoxicity and hyperglycaemia. These features of systemic envenomation can all be attributed to the toxic properties of Oriental hornet venom described in in vitro and in vivo experimental studies. Greater awareness of these features, aggressive treatment of hyperkalaemia and early institution of treatments such as peritoneal dialysis and plasma exchange may prevent fatalities in such cases.

Cortical cerebral blood flow is enhanced by hornet venom

This study examined the effect of Oriental hornet venom sac extract (VSE) on the rate of local blood flow in the cerebral cortex of rats. Sublethal doses of VSE in isotonic saline solution were injected into the femoral vein of anaesthetised rats and the rate of blood flow was assessed by the hydrogen clearance technique both before the envenomation as well as during the following 150 min. The injection of VSE was found to induce a prolonged elevation of blood flow in the cerebral cortex. The time of occurrence of this elevation varied in different rats and so also the intensity of the elevation, ranging between 47-212% of the basal values. No exceptional or toxic phenomena were recorded in the course of this investigation. It would seem that the factor(s) responsible for boosting the blood flow is probably one or more of the water soluble components of the hornet venom.

Evoked potential changes in cats following injection of an extract from the venom sac of the oriental hornet (Vespa orientalis)

Venom sac extract from the hornet Vespa orientalis was injected (via the subclavian artery) into cats and its effects on evoked potentials in two different sensory pathways (auditory and somatosensory) was investigated. A comparison was made between the venom sac extract from adult hornets and that from young (0-24 hr of age) hornets. There was a bimodal change in blood pressure, a hypothermic effect and a decrease in amplitude of the last waves of the auditory and somato sensory pathways when venom sac extract of adult hornets was injected. Venom sac extract from young hornet workers had the same influence on the blood pressure, did not affect thermoregulation and the effect on the auditory and somato sensory pathways were less consistent. Adult venom sac extract had mainly a central effect whilst the venom sac extract from young hornets (in larger doses) affected the central and/or peripheral nervous system. The central effects could be interpreted as due to opening of the blood-brain barrier by the venom.

Liver damage induced by Oriental hornet venom sac extract at the level of subcellular fractions

The hepatotoxic effect of venom sac extract (VSE) of the Oriental hornet has already been demonstrated using the well-known models of experimental toxicology: in vivo, isolated in situ and in vitro. The present work deals with a series of 48 rats treated daily with 5 mg VSE/kg body weight for 1-14 days. Serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT) were measured. Liver tissue fractionation was performed. Detailed information on the topographical and functional aspects of some enzyme changes was obtained in respect to the number of envenomations. The biochemical alterations are partially reversible. The biochemically proven liver damage induced by VSE correlated well with previous electron microscopic observations of damage to mitochondria and cell membranes.

Histopathological changes in rat liver following repeated vespine envenomation

The histopathological picture of rat liver was studied after repeated envenomation with hornet (Vespa orientalis) venom sac extract (VSE). Light microscopical and histochemical investigation showed foci of necrosis of the hepatocytes, a decrease in glycogen content and in succinic dehydrogenase activity, some fat infiltration and an increase in alkaline phosphatase activity. Electron microscopy showed a decrease in the number of mitochondria per cell as well as a decrease in their cristae, enlargement of bile canaliculi, and destruction of the endothelium of the sinusoids bringing the cytoplasm of the necrotic hepatocytes in contact with the lumen of the sinusoid. The rat liver is proposed as a model for the study of pathological effects of animal toxins.

Hepatotoxicity of hornet's venom sac extract, after repeated in vivo and in vitro envenomation

The activity of some enzymes involved in hepatic function was measured in rats, in vivo, after one week's repeated envenomation with Hornet's (Vespa orientalis) venom sac extract (VSE) and in vitro in monolayers of tissue culture of rat hepatocytes treated with VSE. The maximal serum enzymatic changes observed in vivo were significant: twenty fold rise of alkaline phosphatase (ALP), a 7-8 fold rise of aspartate aminotransferase (AST) and a 4-5 fold rise in alanine aminotransferase (ALP) activity. Also 2-3x increases of both serum lactic dehydrogenase (LDH) and creatine phosphokinase (CPK) were noted. The maximal in vitro changes were observed after six days of daily envenomation. There were five fold rises of the activity of AST in the medium, as well as of two-three fold rises of ALT, ALP and LDH. These changes suggest that Hornet's VSE induces enzymatic changes in the liver after prolonged, repeated exposures. They also exclude a general effect, like shock, that might possibly occur in the intact animal, as the cause of the demonstrated hepatic damage.

Hypothermia induced in mice by injection of venom sac extract of hornets (Vespa orientalis, vespinae: hymenoptera)

Intraperitoneal injection into naive and immunized albino mice of Oriental hornet venom sac aqueous extract induces within 3 h an 8-10 degrees C and 3-4 degrees C drop in body temperature, respectively. The fall in temperature is dose-dependent. The responsible fraction(s) in the venom is of high molecular weight.

Hornet (Vespa orientalis) venom sac extract causes hepatic injury in cats

1. Injection of sublethal doses of hornet venom to cats was followed by increases in serum aminotransferases and alkaline phosphatase, together with hyperglycemia, uremia and hyperkalemia. 2. The blood pH and PO2 fell significantly. 3. All changes occurred within 30 min of injection and were found to be partially reversible. 4. These results may be due to specific liver cell injury. 5. The possibility of a generalized metabolic effect, such as shock, cannot be discounted, although it is quite unlikely.

Proteins in venoms of two wasps, Polistes comanchus navajoe and Vespa orientalis

1. By means of gel electrophoresis the basic proteins in venoms of Polistes comanchus navajoe and Vespa orientalis were resolved into 6 and 5 proteins respectively, all of molecular weights greater than 15,000. 2. Several proteins appeared to be similar in both venoms. 3. The main component of P. comanchus venom responsible for hemolysis was isolated, and data concerning its thermolability, molecular weight (approximately 26,000) and amino acid composition show that unlike the cytolytic components of bee and ant venoms which are small peptides, the corresponding functional entity of P. comanchus venom (polistin) is a protein having the characteristics of an enzyme.

Effects of caffeine and various xanthines on hornets and bees

The effect of caffeine was assessed on Vespa orientalis hornets maintained either in sealed breeding boxes or as entire colonies free to forage, and also on Apis mellifera bees within their hives. In a number of instances the hornets were also used to study the effect of various bodily extracts of queen hornets and of the following xanthines: Purine; hypoxanthine; uric acid; theophylline; and theobromine. The studied materials were found to exert an effect on three categories of activities: (1) Motor motility, flight, and construction; (2) sensory response to light (retinal and extraretinal), noise, irritability, orientation; and (3) physiological changes in appetite, copulation, oviposition, hibernation, resistance to cold, and longevity. Up to a point the produced effects were reversible. Throughout the period of experimentation the test insects did not show signs of tolerance or addiction towards caffeine.

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.