Effectiveness of Anti Scorpion Venom for Red Scorpion Envenomation.

Objective: To study the efficacy of anti-scorpion venom plus prazocin. Methods: Comparison of clinical features, outcome and duration of stay between children receiving anti-scorpion venom plus prazocin or prazocin alone for management of red scorpion envenomation. Results: Requirement for dopamine and requirement and duration of dobutamine therapy were significantly less in patients received anti-venom plus prazocin than those had prazocin only. Faster recovery was seen in cases who received antiscorpion venom plus prazocin than prazocin only group. Conclusion: Anti-scorpion venom plus prazosin was safe and more effective than prazocin alone for scorpion envenomation.

Involvement of AMPA receptors for Mesobuthus tamulus Pocock venom-induced depression of monosynaptic reflex in neonatal rat spinal cord in vitro.

Glutamate is a putative neurotransmitter at Ia-α motoneuron synapse in the spinal cord and mediate the action via N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) receptors. Since NMDA receptors are not involved in M. tamulus Pocock (MBT) venom-induced depression of spinal monosynaptic reflex (MSR), the present study was undertaken to evaluate the role of AMPA receptors in mediating the depression of MSR by MBT venom. The experiments were performed on isolated hemisected spinal cord from 4-6 day old rats. Stimulation of a dorsal root with supramaximal voltage evoked MSR and polysynaptic reflex (PSR) potentials in the corresponding segmental ventral root. Superfusion of MBT venom (0.3 µg/ml) depressed the spinal reflexes in a time-dependent manner. The maximum depression of MSR(~ 66%) was seen at 10 min  and it was 25 min for PSR (~ 75%). The time to produce 50% depression of MSR and PSR was 6.7 ± 1.5 and 10.8 ± 2.6 min, respectively. Pretreatment of the cords with 6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX, 0.1 μM), an AMPA receptor antagonist, blocked the venom-induced depression of MSR but not PSR. The results indicate that venom-induced depression of MSR is mediated via AMPA receptors.

Opinion: Pathophysiological approach to the management of scorpion envenomation.

Indian red scorpion (Mesobuthus tamulus; MBT) produces lethal stings and is a matter of concern in certain parts of India. MBT envenomation produces multi-systemic involvement, thus presents difficulty in the management. Symptomatic treatment has been practiced earlier that failed to relieve the toxic effects of the venom. Therefore, present manuscript deals with pathophysiologically based approach in the management of toxicity considering the merits and the demerits of treatment protocols so as to evolve a consensus in the treatment strategies of scorpion envenomation.

The action of red scorpion (Mesobuthus tamulus coconsis, pocock) venom and its isolated protein fractions on blood sodium levels

Red scorpion (Mesobuthus tamulus or Buthus tamulus) venom samples were collected at different regions of India: western (Chiplun and Ahmednagar from Maharashtra State) and southern (Ratnagiri and Chennai from Tamil Nadu State). The action of whole venoms on the blood sodium levels of mice was assessed using flame photometry. Seven peptides were common to all venom samples. They were separated using the native polyacrylamide gel electrophoresis (PAGE) technique and their activities were also studied using flame photometry. There was a decrease in the concentration of sodium ions in the serum, which suggested the blockage of such ions by scorpion venom toxins. Among the 10 protein bands isolated, the band at 79.6 kDa presented maximum activity in decreasing serum sodium ions concentration. Whole venom from Chiplun region also showed maximum activity. The western blotting technique demonstrated that the anti-scorpion venom sera produced by Haffkine Biopharmaceuticals Corporation Ltd., India, neutralized all four venom samples.(AU)

Intraspecific variation in protein pattern of red scorpion (Mesobuthus tamulus, coconsis, pocock) venoms from Western and Southern India

Red scorpions Mesobuthus tamulus (Coconsis, Pocock) were obtained from different regions of West and South India (Ratnagiri, Chiplun and Ahmednagar from Maharashtra and Chennai from Tamil Nadu, respectively). Their venoms composition was analyzed using gel electrophoresis (SDS-PAGE). All venom samples shared six bands of 170, 80, 60, 57, 43, and 38 kDa molecular weights. Bands of 115 kDa and 51.5 kDa were characteristic of venoms obtained from red scorpions of Chiplun region, and the 26kDa band was absent in scorpion venom from Tamil Nadu. The separated protein band patterns suggest that the venoms from Ratnagiri, Ahmednagar and Tamil Nadu had high similarities in their biochemical composition but differed from that of Chiplun region. These data were also supported by the Jaccard (J) index. The J value was 0.33 for venom obtained from Ratnagiri-Ahmednagar, 0.31 for venom from Ratnagiri-Tamil Nadu, and 0.3 for venom from Ratnagiri-Chiplun region. This suggests the existence of genetic variation among the different strains of red scorpion in western and southern India. The antiserum produced by Haffkine Biopharmaceuticals Corporation Ltd. completely neutralized proteins of venoms from all the regions studied.(AU)