Fractionation of scorpion (Leiurus quinquestriatus H and E) venom

Dose-dependent serum biochemical alterations in Wistar albino rats after Palamneus gravimanus (Indian black scorpion) envenomation

Palamneus gravimanus envenomated rats showed dose-dependent alterations in serum biochemical parameters. Sub lethal doses of 100, 200, and 400 microg/kg of P. gravimanus venom were injected intramuscularly into rats. Blood samples were collected by heart puncture before and 4 h after crude venom administration. Serum was analyzed for glucose, blood urea nitrogen (BUN), uric acid, total protein, cholesterol, sodium, potassium, inorganic phosphorus, alkaline phosphatase, aspartate aminotransferase (AST-SGOT), alanine amino-transferase (ALT-SGPT), lactate dehydrogenase (LDH), and creatinine phosphokinase (CPK). Statistically significant increases in serum levels of glucose, creatinine, AST, ALT, BUN, CPK, and LDH and significant decreases in serum levels of total protein, uric acid, cholesterol, calcium, and potassium 4 h after venom administration could be due to the toxic action of P. gravimanus venom on certain organs in rats.

Effect of scorpion Leiurus quinquestriatus (H&E) venom on the clinical chemistry parameters of the rat

Egyptian scorpion venom was collected by electrical stimulation of the telson. Rats were injected with the lyophilized venom in 3 different doses (100, 200 and 400 micrograms/kg). Blood samples were drawn by heart puncture before and 4 h after venom administration. Serum was separated and collected for determination of glucose, blood urea nitrogen (BUN), creatinine, uric acid (UA), total proteins, cholesterol, sodium, potassium, calcium, inorganic phosphorus, alkaline phosphatase, aspartate aminotransferase (AST, GOT), alanine aminotransferase (ALT, GPT), lactate dehydrogenase and creatine phosphokinase (CPK). Serum glucose, creatinine, GOT, GPT and LDH were increased significantly in all treatments. At the same time serum BUN and CPK were elevated significantly with a dose-response relationship. On the other hand, serum total proteins, uric acid, cholesterol, calcium and potassium were significantly decreased 4 h after administration of the 3 doses. These changes in clinical chemistry parameters are most probably related to the toxic effect of the venom on the target organs.

Are the toxicological effects of scorpion envenomation related to tissue venom concentration?

The pharmacokinetics of 125I-labelled Androctonus amoreuxi venom and its lethal fraction was studied in rabbits. Comparative pharmacokinetic studies of labelled A. amoreuxi, Leisurus quinquestriatus and Buthotus judaicus venoms were carried out in guinea-pigs. The pharmacokinetics of A. amoreuxi venom was also studied in rats. Groups of rats were injected with labelled A. amoreuxi venom and killed at frequent time intervals for the determination of the relative tissue venom concentration as a function of time. Several groups of rabbits were injected with A. amoreuxi venom and serial blood samples withdrawn at time intervals comparable with those used in the pharmacokinetic studies for the determination of serum glucose, insulin, cortisol, total proteins, albumin, globulins, cholesterol, total bilirubin, urea, uric acid, bicarbonate, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, sodium, potassium, calcium and phosphorus. The packed cell volume, and total and differential leucocyte counts were also determined. In another series of experiments continuous monitoring of the electrocardiograms of rabbits following venom injection was made to correlate any abnormalities with tissue venom concentration. All three venoms and the lethal fraction showed an open two-compartment behaviour with rapid distribution half-lives ranging between 4 and 7 min and overall elimination half-lives of 4.2 to 13.4 hr. The behaviour of A. amoreuxi venom was not markedly different in the three species of animals used. In a given species (guinea-pigs) the behaviour of the three venoms was not markedly different. Correlation of the ECG changes with cardiac venom concentration showed that arrhythmias and infarction occurred at times when cardiac concentration was very low, indicating that the cardiac abnormalities might result from indirect factors. Comparison of the course of the biochemical changes with venom concentration in the central compartment indicated that the site of action of the venom is not located in the central compartment. Correlation of the intensity of the biochemical effects with venom concentration in the peripheral compartment revealed an apparent delay in the onset and peak of action. This was explained by assuming that the tissue compartment could be divided into a rapidly accessible and a slowly accessible compartment with the venom acting through the slowly accessible compartment. There was also the possibility of the venom acting indirectly through the release of other substances or transformation to an intermediate.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of a cercarial toxin derived from venom of the scorpion Leiurus quinquestriatus on frog skeletal muscle

Cercarial toxin, a protein purified from Leiurus quinquestriatus venom and toxic to Schistosoma mansoni cercariae, was examined for its effects on frog twitch muscle fibres. In concentrations of 3.4-12 microM the toxin, after a delay of several minutes, produced a slowly developing depolarization of the resting membrane and high frequency miniature endplate potentials associated with spontaneous firing of muscle fibre action potentials and twitching. The action potential duration increased from about 3 to more than 100 msec. In advanced stages of poisoning the amplitude of action potentials decreased while oscillations on the plateau level occurred. Short electrical pulses were followed by repetitive firing of prolonged action potentials, while long stimuli elicited long-lasting action potentials with oscillations on the plateau level. Addition of d-tubocurarine blocked spontaneous sub- and suprathreshold activity. Increasing the Ca concentration of the medium markedly shortened the action potentials and stopped repetitive firing. It is concluded that cercarial toxin interferes with the ionic permeabilities of frog twitch fibres in a way similar to that reported for crude venom or one of its highly toxic fractions in frog nerve.

Effect of a scorpion (Leiurus quinquestriatus H and E) venom on blood gases and acid-base balance in the rat

Leiurus quinquestriatus crude venom caused metabolic alkalosis which was partially compensated by respiratory acidosis. Fraction 1 of the venom caused metabolic and respiratory acidosis. The other fractions caused metabolic alkalosis with various degrees of compensation by respiratory acidosis. Fraction 1 caused a marked decrease in blood pH. Hypoxia seemed to be an important contributing factor for this change. Sodium levels decreased while potassium levels increased in the plasma.

Investigations on the venom of the South Indian scorpion Heterometrus scaber

The enzymes from the venom of Heterometrus scaber, the indole compounds present and the toxic protein of the venom have been studied. The venom contains acid phosphatase, ribonuclease, 5'-nucleotidase, hyaluronidase, acetylcholine esterase and phospholipase. A. The indole compounds present in the venom have been identified as 5-hydroxytryptophan, tryptophan, serotonin and tryptamine, along with two unidentified indole compounds. The venom produces hyperglycaemia in sublethal doses and this has been found to be due to increased adrenaline secretion. The toxic protein of the venom has been obtained in a pure form by (NH4)2SO4 fractionation, followed by fractional precipitation with acetone and chromatography over DEAE-Sephadex. The toxic fraction has been found to be homogeneous on acrylamide gel electrophoresis. It is a glycoprotein (molecular weight 15 000) containing 1.74% glucosamine, 0.87% galactosamine, 0.313% sialic acid, 3.25% fucose and 0.45% of an unidentified neutral sugar. It did not show any enzyme activities, haemolytic activity or inhibition of succinate dehydrogenase activity but it produced hyperglycaemia in sublethal doses. The toxic level (intravenous administration in rats) was found to be 0.72 mg/kg body weight.