In this video, we're going to begin our introduction to ecosanoids. Now before we get started, let's take a look at our lipid map here to make sure we're all on the same page. And of course, we know that we're currently exploring the fatty acid based lipids. And already in our previous lesson videos, we've explored the glycerolipids, the sphingolipids, and waxes. And so now we're introducing eicosanoids, another type of fatty acid based lipid. And so these ecosinoids are really just fatty acid based lipids that are derived from c 20 polyunsaturated fatty acids or unsaturated fatty acids that have multiple double bonds and a total of 20 carbons, like, arachidonic acid for instance, whose shorthand name we're providing here. And so many of these eicosanoids are derived, specifically from this arachidonic acid. Now the name ecosanoids is actually derived from the Greek word ecosi, which means 20. And so this speaks to the c 20, polyunsaturated fatty acids. Now there are really 3 main classes of eicosanoids that we're going to talk about moving forward and these are the prostaglandins, thromboxanes, and leukotrienes. And so moving forward, we'll talk about each of these 3 different types of eicosanoids in their own separate videos. But if we take a look down below at our image, notice we're showing you the structure of arachidonic acid, which you'll notice is a c twenty polyunsaturated fatty acid. It's a fatty acid because it has a carboxylic acid and a long chain hydrocarbon, and there are exactly 20 carbon atoms, and it is definitely polyunsaturated because there are multiple double bonds. And arachidonic acid again is going to be, the precursor to all of these other ecosonoids that we see down below. The prostaglandins, thromboxanes, and the leukotrienes. Again, which are all ecosinoids. And so, in our next lesson video, we'll be able to talk about, the general function of these ecosinoids And then we'll talk about each of these 3 individually in their own separate video. So I'll see you guys in our next video.
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Eicosanoids
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In this video, we're going to talk about the functions of ecosanoids. And so ecosanoids actually have a wide variety of functions. And so they have so many different functions that we're not gonna be able to talk about all of their different functions. But one thing to note about ecosonoids is that they usually act as special types of hormones. Now, I'm sure all of you have probably heard of the word hormones before but what exactly are hormones? Well, hormones are really just defined as bio signaling molecules. So, they allow cells to communicate with each other and to affect each other. And so hormones, more specifically, these are bio signaling molecules that are gonna be released by a cell or a gland and can actually travel and affect distant cells in a completely different area of the body. Now, again, ecosonoids act as special types of hormones and so, really, ecosonoids are going to function as what are known as paracrine hormones. And so, really, this paracrine here is just hinting at the fact that they still act as signaling molecules, but they do not travel and affect distant cells in other areas. Instead, paracrine hormones act only on nearby cells in the vicinity of its synthesis. And so this allows ecosonoids to act or function at very, very low concentrations. You don't need a lot of, the ecosanoids in order to get a function. And these ecosanoids, they actually tend to decompose within just a few seconds or minutes. And really, that's what limits their travel and allows them to function as paracrine hormones. Now again, moving forward in our course, we're going to talk about the 3 different types of eicosanoids, starting with the prostaglandin. So I'll see you guys in that video.
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Eicosanoids
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In this video, we're going to talk about our first class of eicosanoids, which are the prostaglandins. And so prostaglandins are commonly abbreviated as just PG. And really, the reason that they're called prostaglandins is because when they were first discovered, they were isolated from the prostate gland, but it turns out that they're actually way more prevalent in other tissues other than the prostate gland. Now these prostaglandins really they're just ecosonoids that contain a 5 carbon ring or a cyclopentane ring. And because again, prostaglandins are ecosanoids and ecosy means 20, that means that they're still going to be derived from c 20 polyunsaturated fatty acids like arachidonic acid. And so you can see here in our image that arachidonic acid is the precursor molecule for prostaglandins such as prostaglandin e 2 here, whose structure we're showing you here. And again, prostaglandins contain 5 Carbon Cyclopentane rings, and so you can see the cyclopentane ring right here. And so really you could think the p here in prostaglandin is for the p in cyclopentane ring, and so hopefully that will help you guys remember that prostaglandins are eicosanoids with a cyclopentane ring. Now in terms of the functions of prostaglandins, they actually have many many many different types of functions. So we're not gonna be able to get into all of the different functions of prostaglandins. But some of their primary functions include regulating pain, fever, and inflammation, as well as affecting blood flow and smooth muscle contractions. And so just as a reminder of their role in regulating pain, fever, and inflammation, we have an image here of this sick kid who's got a thermometer in his mouth and, he's trying to regulate his pain, fever, and inflammation. And so, this here concludes our introduction to prostaglandins and in our next lesson video, we'll be able to talk about our second type of ecosanoid which are the thromboxanes. So, I'll see you guys there.
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Eicosanoids
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In this video, we're going to talk about our second class of ecosonoids, which are the thromboxanes. Now thromboxanes are again a specific class of ecosinoids that have instead of a 5 membered ring like prostaglandins, they actually have a 6 membered ring with an ether group. And again, because thromboxanes are ecosinoids and ecosi means 20, these are derived from c 20 polyunsaturated fatty acids, such as arachidonic acid. And so arachidonic acid is the precursor to thromboxanes such as thromboxanes a 2 over here. And notice that the thromboxanes do have 6 membered rings just like this one right here. And the 6 membered rings also have ether groups like this blue one that we see right here. One way that helps me remember that thromboxanes have 6 membered rings is that I think about a box that has a hexagon shape or 6 sides. And so, by thinking about the box, it helps me remember that this is going to be a, 6 membered ring or include a 6 membered ring. Now, the reason that thromboxanes are called thromboxanes is because they're actually produced by platelet cells, otherwise known as thrombocytes. And so thrombocytes or platelets, they play a big role in the formation of blood clots. And that's because the thromboxanes that they produce will help to initiate, blood clot formations. And thromboxanes are also important for reducing blood flow to the clot. And so if you ever get injured and get a cut, it's important for your blood to be able to create a clot to make sure that you do not lose too much blood. And again, the thromboxanes are very important in this process. And so this here concludes our introduction to thromboxanes. And in our next video, we'll be able to talk about the 3rd class of eicosanoids, which are the leukotrienes. So I'll see you guys there.
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Eicosanoids
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In this video, we're going to talk about our 3rd class of eicosanoids, which are the leukotrienes. And so, leukotrienes, of course, are ecosonoids, and as their name implies, the tri indicates that there are 3, and the enes are indicating the presence of double bonds. And so indeed, leukotrienes are ecosinoids that have 3 conjugated double bonds. And, of course, because these are ecosinoids ecosanoids and the Greek word ecosi means 20, leukotrienes are derived from c 20 leukotriene d 4 whose structure we're showing you here. And again, leukotrienes as the name implies, they have 3 conjugated double bonds. And so when you take a look at the structure here, you can see that these 3 double bonds right here, are conjugated double bonds. And so there are 3 conjugated double bonds. Now by conjugated, really what we mean is that they're just appearing back to back here, in this particular fashion. Now notice that this double bond down here is not conjugated because it's being separated from the others by a ch 2 group. And so the reason that leukotrines are called leukotrines is because they're predominantly expressed by leukocytes, which is really just the scientific name for white blood cells. And so our white blood cells produce these leukotrienes. Now, the leukotrienes actually have variable different functions, but they predominantly act as powerful biosignals. For example, leukotriene d 4, will actually induce strong smooth muscle contractions of our lungs. And of course, in some people, allergic reactions can trigger leukotriene synthesis. And so if leukotriene d 4 is being synthesized, or overexpressed, it's going to induce strong smooth muscle contractions of the lungs. And that could lead to an asthma attack. And so, if you guys know people that have asthma, it's really because of the allergic reactions are causing them to over create leukotrienes, specifically leukotriene d 4. And so down below in our image, notice that we've got this guy right here, who is having an asthma attack because of the overproduction of leukotriene d 4. And, notice that he's using this inhaler here and the inhalers will actually have specific molecules that block receptors for leukotriene d 4. And so that's just something interesting, to note. But really this here concludes our introduction to leukotrienes and moving forward we'll be able to apply these concepts that we've learned in our practice problem. So I'll see you guys there.
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Problem
Problem
Which of the following fatty acids is the precursor to the eicosanoids?
A) Arachadonic Acid.
B) Palmitic Acid.
C) Steric Acid.
D) Oleic Acid.
E) Carboxylic acid.
A
Arachadonic Acid.
B
Palmitic Acid.
C
Steric Acid.
D
Oleic Acid.
E
Carboxylic acid.
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Problem
Problem
Which of the following is true regarding eicosanoids?
A) All eicosanoids contain three conjugated double bonds.
B) All eicosanoids contain arachidonic acid and sphingosine.
C) Prostaglandins and leukotrienes both contain a ring structure.
D) Thromboxanes, prostaglandins & leukotrienes all contain a carboxyl group.
A
All eicosanoids contain three conjugated double bonds.
B
All eicosanoids contain arachidonic acid and sphingosine.
C
Prostaglandins and leukotrienes both contain a ring structure.
D
Thromboxanes, prostaglandins & leukotrienes all contain a carboxyl group.
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Problem
Problem
Prostaglandins are local regulators whose chemical structure is derived from:
A) Oligosaccharides.
B) Fatty Acids.
C) Steroids.
D) Amino Acids.
E) Isoprenoids.
A
Oligosaccharides.
B
Fatty Acids.
C
Steroids.
D
Amino Acids.
E
Isoprenoids.
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Problem
Problem
Non-steroidal anti-inflammatory drugs (NSAIDS), like aspirin & ibuprofen, lower body temperatures by blocking production of which eicosanoid?