Introduction
Ouabain is a glycoside for the heart and, in lesser doses, it can be utilized to treat hypotension as well as some arrhythmias.
It works by blocking the Na/K-ATPase, which is also known as the sodium-potassium-ion pump.
However, modifications to the alpha-subunit Na+/K+-ATPase, through amino acid substitutions were observed on specific species. Specifically the herbivore-insect species which have led to resistance to toxins.
This substance has been classified a highly dangerous chemical throughout the United States as defined in Section 302 of the U.S.
Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002) and is subject to stringent reporting requirements by all facilities that manufacture, store, or utilize it in large quantities.
ouabain
Sources
Ouabain is located in the roots stems, leaves, as well as the seeds of Acokanthera Schimperi and Strophanthus Gracious plants Both are indigenous to the eastern part of Africa.
Mechanism of action
Ouabain is a glycoside in the heart which acts by inhibiting sodium-potassium ion-pump (but it’s not selective). Once the ouabain has bound to this enzyme, it ceases functioning, leading to an increase in intracellular sodium.
This rise in intracellular sodium diminishes the function. That the sodium calcium exchanger (NCX) that pump one calcium ion out the cell, and three sodium ions into cells down the gradient of their concentration.
This is why the decrease in the gradient of concentration of sodium in the cell. Which happens when the Na/K-ATPase enzyme is blocked hinders the capability to allow the NCX to perform its function.
This causes an increase in intracellular calcium. This leads to increased cardiac contractility as well as an increase in the cardiac vagal tone. The changes in ionic gradients that are caused by ouabain may alter the voltage of the membranes of cells, resulting in arrhythmias of the heart.
The signs
A high dose of ouabain may be identified by the appearance of these symptoms. That include rapid twitching in the chest and neck muscles breathing distress, an increase and irregular heartbeat, increase in blood pressureand convulsions wheezing and clicking, as well as gasping rattle.
The cause of death is cardiac arrest.
Toxicology
Ouabain is a very toxic chemical with an LD50 that is 5 mg/kg it is administered in rodents’ stomachs.
But, it is not bioavailable and is not well absorbed by the digestive tract. As most of the oral dose is eliminated. Injecting it intravenously results in higher available levels and has been demonstrated to reduce levels of LD50 by 2.2 mg/kg, even in rodents.
After intravenous administration the beginning of the action takes place within 2 to 10 minutes. In humans with the greatest effect lasting over 1.5 hours.
Ouabain is eliminated via excretion from the kidney, which is mostly unaltered.
Find Latest insight Health in The Mail Online
