Scorpion venom research around the world: Indian Red Scorpion

The Indian red scorpion is the medically most important scorpion on the Indian subcontinent, and a sting is often lethal without treatment, especially to young children. The correct identification of this species is Hottentotta tamulus; the more commonly known names, Buthus tamulus and Mesobuthus tamulus, and the suggestions of subspecies (Pocock) are incorrect and should be discouraged. Mild cases of H. tamulus envenoming show vasoconstriction and hypertension resulting from a massive release of catecholamines. Severe cases result in hypotension, pulmonary edema and myocardial dysfunction. Animal studies indicate that catecholamine release is as a consequence of prolonged sodium channel activation and potassium channel inhibition. Pulmonary edema results from many subcellular events, including kinin activation and stimulation of central serotonin receptor subtypes. Treatment with a specific antibody (with or without the a-adrenoreceptor blocker, prazosin, dependent on symptoms and clinical severity) is presently the preferred therapy. The few venom constituents that have been characterized in detail include iberiotoxin, a specific blocker of high conductance, calcium-activated potassium channels; tamapin, a specific blocker of low conductance calcium activated potassium channels (KCa 2.2 subtype); and the short peptide insectotoxins, ButaIT and BtlTx3.