3. Blood Disorders. Blood disorders such as hemophilia and leukemia can cause unexplained bruising, often because your blood fails to clot properly. If you have severe and frequent unexplained bruising, it's a good idea to see a physician to rule out such disorders, especially if it seemed to come on suddenly.
Puffer fish contain the potent neurotoxin tetrodotoxin. TTX is thought to be synthesized by a bacterial or dinoflagellate species associated with the puffer fish. The toxin is concentrated in the liver, gonads, and skin. The level of toxicity is seasonal, and, in Japan, fugu is served only from October through March.
Tetrodotoxin inhibits the firing of action potentials in nerves by binding to the voltage-gated sodium channels in nerve cell membranes and blocking the passage of sodium ions (responsible for the rising phase of an action potential) into the nerve cell.etrodotoxin binds to what is known as site 1 of the fast voltage-gated sodium channel. Site 1 is located at the extracellular pore opening of the ion channel.