February 8, 2023

A simple explanation of how ACE inhibitors work, with an overview of the renin-angiotensin system.

So i wanted to explain how ace inhibitors worked and i think the thing that helped me understand this the fastest was just to think of sodium increasing blood pressure so soon as sodium increases i was talking about in the blood and in the body blood pressure increases and i think of this in just in terms of if you have more salt in a solution it’s going to draw the

Water from other areas so if you have more salt in your blood it’s going to draw more water from the rest of your body into your bloodstream and therefore increase your blood pressure so the next step to understanding this whole process about how ace inhibitors worked is just to understand the renin-angiotensin system so and i quickly go through that now and the

Story sort of starts over here i’m sorry for my terrible drawing but this is a glomerulus and if you remember this is where blood filters or things filter from your blood through the glomerulus and across the basement membrane and into your nephron so this is stuff in your blood and then it filters out and this is essentially urine that passes down there into your

Bladder and these little dots here represent the juxtaglomerular apparatus and these these are jokes with glomerular cells essentially sends sodium and blood pressure so as the sodium falls in these cells and the blood pressure falls in these cells they produce an enzyme that’s called renin and when in renison and renan is an enzyme produced a response to those

From the juxtaglomerular cells now this is riped my representation of a liver and inside the liver that sits something called angio 10 syn hojin angiotensinogen and don’t really do much until renan comes along and converts it into angiotensin 1 so without renin-angiotensin just sits in a lever doing nothing when renan is produced in response to this it converts

The angiotensinogen to angiotensin 1 now angiotensin 1 doesn’t really do much just sits in your blood floating around until it comes into contact with something called angiotensin converting enzyme which basically does what it says on the tin it comes from the lungs it sits in the lungs and as this angiotensin passes through the blood vessels and the lungs and the

Angiotensin converting enzyme turns it from angiotensin 1 to angiotensin 2 now the angiotensin 2 is important for a number of reasons it actually does something so this is the key part now it does a few things but all of them essentially amount to an increase in blood pressure so the way it does this is it acts directly firstly on the thirst center so it increases

Thirst and if you increase first you drink more water and that water has an effect to increase the volume in your blood so essentially increases your blood pressure so it compasses that that way the second thing that it does his razor constriction so the angiotensin to phaser constricts your blood vessels and if you constrict them you’ll increase the pressure so

In that sense it increases the blood pressure now the third thing it does is it acts this is my little drawing of a kidney it’s wearing a hat and the hat is essentially the adrenal cortex and on the outer layer of the adrenal cortex which is called the glomerulus just to complicate things is produced something called aldosterone that’s in another just zero that’s

Our dosterone acts on the kidneys and it acts on the distal tubules as they as they come past and it causes reabsorption of sodium reabsorption of sodium from the from the nephron or from the urine essentially back into the blood so by doing that it increases the sodium in the blood and increases the blood pressure so this clever system essentially takes you from

The juxtaglomerular cells sensing a low sodium and a low blood pressure through a number of different steps to increasing your sodium and increasing your blood pressure i’ve already established that the running the angiotensinogen the angiotensin ii don’t particularly do much in this system they’re just steps along the way it’s only when you get the action of

The angiotensin converting enzyme to convert angiotensin 1 to angiotensin 2 that you end up with all of these effects that end up increasing sodium and increasing your blood pressure so if we can block this this with the ace inhibitors you then block this pathway and you block all of this from happening and so you don’t get an increase in sodium you don’t get an

Increase in blood pressure so you’re just left with this system and as a result ace inhibitors work to reduce your blood pressure and reduce your sodium simple as that

Transcribed from video
How do ACE inhibitors work? By Zero To Finals