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Current time:0:00Total duration:5:54

Video transcript

so in our body we have DNA and RNA these are our genetic material and they're constantly broken down or remade as new cells are made this new processes take place so they get broken down through a variety of pathways and I'm simplifying that a lot the details but the end result and there are two kind of materials that we end up with one is called hypo xanthine hypo xanthine the other one is guanine and they both get further broken down into the same thing which is xanthine and then that is the precursor to uric acid uric acid is the thing that accumulates and causes gout are the symptoms of gout so as you can see it's a normal part of this physiological pathway that we need uric acid by itself is not a bad thing so what happens to it usually in a healthy person is that the kidneys take care of it they filter it out of the blood and in terms of where things go after the kidney there's only two ways to go one it's out of the body this is going to be waste so basically in urine it's out of your body and this one is of course back to the body and under the best circumstances uric acid most of it gets filtered through the waste it leaves and it's not a problem it's only when it accumulates in a body do we have gout so then there are two different places this system can give us trouble one is where we make too much uric acid in that case we would look to this pathway and see why do we have more and the other place is the kidney not doing its job filtering well and the problem comes here we're not enough of it leaves the body is waste so these are the two big umbrellas in terms of the pathophysiology of gout first we have primary gout and I've learned that in medicine whenever they say primary just means we don't know something intrinsic to the body is causing the problem we don't know exactly which one it is and secondary is really the processes we can study so since we don't know about primary we just talked about the secondary causes and first if we think about what we tell patients with gout is that first don't eat a lot of meat and second don't drink a lot of alcohol and these two things actually belong in two different places here on our pathway so eating too much meat causes more uric acid in our blood and that comes from here DNA and RNA just by consuming animal products we not only have to break down our own but we have to break down theirs so in the gut the proteins get broken down and eventually we have to do this to the animal proteins in addition to our own so this is how eating more meat can lead to symptoms of gout but then alcohol is actually over here alcohol gets broken down and alcohols break down products actually competes with uric acid in the kidney so it's like if you're in a hall and there's three doors to get out usually uric acid should be if there's the only thing occupying this space then technically the filtration system should be able to get rid of it but when we add alcohol to the mix it just so happens to use the same exits as uric acid so this physical crowding mechanically slows down the filtration so alcohol makes it harder to get rid of uric acid and this is assuming the kidneys are normal of course we can also have just kidney disease and there's a whole I mean there's a whole branch of medicine for it but the umbrella term that we use is renal insufficiency we know meaning keep kidney insufficiency meaning is not doing its job so other diseases that cause kidney failure or lowered kidney function would give ask out as well and here in the uric acid side what else can lead to more breakdown of our DNA RNA and cause more you're guessing while certain cancers like leukemia actually lead to more destruction of our blood cells and this recycle system just goes into overdrive there's more DNA and RNA of our own being broken down inside from leukemia there's other blood disorder so if this is our bone blood cells are made in the bone marrow and whatever disease that happens ramps up the bone marrow and over reduction of the blood cells that we have over break down as well so leukemia and other blood disorders can cause that it's another illness that's kind of unique it's called Lee Shahan named after the people who discovered it and clinically it's an interesting disease it causes people to hurt themselves they bite themselves to cut themselves and there's brain damage and nerve damage but on this pathway leave dying occurs at this level so if we look at our pathway it looks like these just have to go become xanthine become uric acid but there's actually a salvage pathway kind of an escape hatch and the person piloting this escape route is something called H P R T it's an enzyme it's a huge name it stands for hypos anthing quaniee phospho rival cell transferase so this enzyme can alter both hypo xanthine and guanine and change it into earlier things in the pathway kind of like recycling something that was going down the trash chute and in leash gnaw and this is the thing that's no longer working so basically without the escape route taking away some of the burden of this breakdown we end up with more uric acid so it doesn't matter why we have more uric acid whether it's more breakdown or not getting rid of enough of it this is a key to gout and in diagnosing gout we have to evaluate where on this pathway the problem is