Page 23 - BIOCHEMISTRY II
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2. Inhibitors of active transport:
A) Ouabin (cardiac glycoside):
•Inhibits adenosine triphosphatase (ATPase) necessary
for hydrolysis of ATP that produces energy of sodium
pump.
•Is a plant derived toxic substance that was traditionally
used as an arrow poison in eastern Africa for both
hunting and warfare.
•Ouabain is a highly toxic compound with an LD50 of
5 mg/kg.
B) Phlorhizin: Inhibits the binding of sodium in the
carrier protein.
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