Since we mentioned renal hypertension as a cause of hyperaldosteronism, let’s go over hypertension.
What is the normal blood pressure?
A typical normal blood pressure is like 120/75 or 120/80 and the units are mm of Mercury, known as TORR. We’ll learn about the two numbers further later. What’s the definition of high blood pressure? As a definition, it’s 140/90… some say 135/85 is borderline high blood pressure. What is the cause of high blood pressure? Well, there’s two MAJOR types of different types of hypertension, just like how there’s two types of diabetes (mellitus and insipidus)
1. Essential / Primary / Idiopathic hypertension. Idiopathic means “We don’t know what’s causing it” however the general consensus is that it’s probably due to atherosclerosis (atherosclerotic plaque on the coronary arteries). This is the most common type of hypertension.
2. Renal hypertension is due to hyperaldosteronism, excessive levels of aldosterone hormone, which cause your kidneys to retain higher amounts than normal of salt and water, which raises your blood volume and raises your blood pressure.
Drugs used to treat Hypertension
There’s many drugs to control high blood pressure and it’s a massive subject you’ll go over in your clinical classes. The first two we’ll go over are the Beta Blockers.
1. They work as sympatholytics (adrenergic blockers). What does stress do to your blood pressure? It raises it. They will use drugs that block this sympathetic response, especially on your heart, to not allow the blood pressure to increase.
2. RAA Blockers (diuretics). This would make sense during hyperaldosteronism. Diuretics. Many are renin-angiotenson-aldosterone blockers, in other words, they block the RAA reflex and by blocking the RAA reflex that reduces the amount of salt and water retention and therefore lowers your blood volume and lowers your blood pressure.
They use both diuretics and beta blockers for both essential hypertension as well as renal hypertension but it certainly makes sense to use the RAA Blockers when you have renal hypertension, because that’s the fundamental problem.
Among the earliest drugs they used to reduce aldosterone action were aldosterone blockers that blocked on the aldosterone receptors on the kidneys. When they discovered that Angiotensin 2 is what causes aldosterone to be made, they made angiotensin 2 blockers such as Cozaar. When they discovered that Angiotensin Converting Eznyme is what made Angiotensin 2, they made ACE blockers such as Accuprill. ACE Inhibitors, which are very popular, end with –IL so you have drugs such as zestril, accupril, quinapril and so forth.
The trend is to develop drugs that block earlier in the sequence because each time you form a new chemical, they have multiplicities of effects and eventually they’ll have something that stops the release of renin.
Example: Check out the wikipedia article for Quinapril. The pharmacological category for Quinapril is a angiotensin-converting enzyme (ACE) inhibitor. It’s use is management of hypertension and treatment of congestive heart failure.
Some new info not found in your textbooks, at least not at this level:
The above link gives you an idea of what you’ll be reading through your professional career. It’s a summary published in 2007 and it’s printed with a title “Skeleton is an endocrine organ.” It talks about a new hormone they’ve discovered that controls our sugar metabolism and weight. This is cutting edge stuff not found in your textbook.
Hundreds of hormones have been identified and we’ve only talked about a few of them so we’re not even close to touching them. What this link above is saying is that people with type 2 diabetes have been shown to have low osteocalcin levels. There are people who inject insulin everyday and are still not without problems, which means that insulin is not the only thing they are lacking or have too much of. They are now seeing that these people are also deficient in osteocalcin and if it proves to be the case, people may also be taking synthetic osteocalcin for their diabetes one day.
Nowadays diabetics may inject insulin but the newest approach is to wear an insulin pump. This is connected by a catheter to their blood stream. They can’t take it off when they take a shower. The benefit is that not only do you not deal with needles, but it only secretes as much blood sugar as you need. This is the next best thing to having a pancreas. This will continue to be the case unless osteocalcin proves to be the case.
Now we made our segway into the cardiovascular system…