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Tangentially, does anyone know how aspirin promotes bleeding? I've searched (and also searched nutrient depletions for aspirin) and I'm not really getting an a
by DoreenMichele 4y ago
Tangentially, does anyone know how aspirin promotes bleeding?
I've searched (and also searched nutrient depletions for aspirin) and I'm not really getting an answer.
- stouset 4y agoIt’s an antiplatelet medication. How it’s that, I haven’t the faintest.
- DoreenMichele 4y agoThank you. That gives me a place to start: https://www.ncbi.nlm.nih.gov/books/NBK537062/ https://www.ncbi.nlm.nih.gov/books/NBK537062/
- cfu28 4y agoAspirin inhibits COX-1 and COX-2 irreversibly, which decreases synthesis of thromboxane which is key to platelet aggregation and vasoconstriction
- wbl 4y agoCOX enzymes produce a promotor of platelet activity and aspirin knocks it out. That's why they thought COX-2 selective inhibitors would be better.
- cfu28 4y agoPrevents arachidonic acid from being converted to thromboxane needed for platelet aggregation. Here's a diagram I find helpful of the arachidonic pathway and which drugs inhibit which parts of the pathway: https://files.mari.casa/aapathway.jpg https://files.mari.casa/aapathway.jpg
- DoreenMichele 4y agoThanks, I'm kind of stuck on the arachidonic acid bit. When I was very ill, I read a comment by a guy with a PhD in chemistry who probably typoed arachidic acid and ..ugh. I need to at some point sort a few things out. Linoleic acid can be converted by the body into arachidonic acid, so that part I got right all those years ago.
- lysozyme 4y agoBlood clotting in mammals is done by platelets, which float around in the blood. Platelets are kind of like (simple) cells in a way. Platelets have a membrane. Inside the membrane are the molecular tools—that’s what I usually call enzymes despite being an enzymologist—they use to clot blood. Inside platelets, chemical reactions are sped along by the enzymes. One of the important chemical reactions for clotting is the conversion of arachidonic acid (through a couple of intermediates) to thromboxane. Now, arachidonic acid is so simple: a linear, 20-carbon chain with a carboxylic acid group at one end, and four double bonds in the chain. Converting it to thromboxane takes a couple of steps: the enzymes need to kink the chain and oxidize specific carbons to make them polar. The trouble is, aspirin inhibits the enzymes! So the enzymes inside the platelets can’t make their thromboxane. And, as such, clotting is inhibited, which results in bleeding. So this is why aspirin can cause bleeding
- greggsy 4y agoThanks - this type of reply is what separates Reddit from HN
- nanidin 4y agoYou can find this kind of reply on Reddit if you’re in the right subreddit. /r/science and /r/drugnerds come to mind as potential candidates.
- greggsy 4y agoThanks - just scrolled through drugnerds, but it’s still an example of Reddit’ preoccupation and persistent desire to prove cannabis as a wonder drug.
- sethammons 4y agoFwiw, chatgpt gave an impressive sounding result that is very inline with sibling comments and would at least give more terms to search for.