Biología celular: investigación y terapia

Scorpion Kaliotoxin Reverses Hyperkalemia, High Serum [K+ ], in Skeletal Muscle

Rohan Lal*

Scorpion toxin causes symptoms such as nausea, muscle twitching, and tachycardia. Kaliotoxin, a scorpion toxin, inhibits voltagegated and leak potassium channels, making cells less excitable. Excess potassium ions increase cell excitability and allow an action potential to occur at a lower threshold voltage. To determine the effects of high [K+] and kaliotoxin, action potential thresholds were measured. Under hyperkalemic conditions, threshold voltage was reduced significantly (p<<0.01) from mean control values. When exposed to high [K+], muscle contraction force showed a significant increase (p=0.03) from control, 1.60g (+/- 0.877; n=5), to 2.56g (+/-1.82; n=5). In the presence of kaliotoxin and hyperkalemic solution, muscle contraction force showed a significant increase (p<<0.01) from 2.07g (+/- 2.07; n=10) to 7.82g (+/- 5.11; n=10) and the latent period showed a significant decrease (p=0.28) from a control value of 0.04s (+/- 0.04; n=10) to 0.03 (+/- 0.03; n=10). Hyperkalemic solutions decreased the threshold level significantly (p<<0.01) while scorpion kaliotoxin, diluted in hyperkalemic solution, allowed the threshold voltage to significantly surpass (p<0.01) normal levels. Scorpion kaliotoxins reduced K+ channel activation and can return cell excitability, under hyperkalemic conditions, to normal. Scorpion kaliotoxin is a potential treatment to reverse the effects of hyperkalemia.