Leukotrienes and lipoxins
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| How do leukotrienes differ from prostaglandins, prostacyclins, and thromboxanes? | linear eicosanoids, not cyclic
🗑
|
||||
| What is the role of leukotrienes? | mediate allergy response, immunity, inflammation
🗑
|
||||
| What is the most serious leukotriene that causes a response 10,000 times (5 orders of magnitude) greater than histamine? | peptidoluekotriene
🗑
|
||||
| Peptidoleukotrienes are known to be the active component of what mediator of intense, violent, often fatal allergic rxns? | slow-reacting substances of anaphylayxis (SRS-A)
🗑
|
||||
| What is the common predominant precursor between cyclic eicosanoids and linear eicosanoids? | arachidonic acid
🗑
|
||||
| The first step of Arachidonic acid metabolism is it's conversion by what to what? | Lipoxygenases (LO) convert it to 5HPETE: hydroperoxyeicosatetraenoic acids
🗑
|
||||
| What final products do the three types of lipoxygenases create? | 5-LO = leukotrienes, 15-LO = lipoxins, 12-LO = hepoxilin
🗑
|
||||
| AFter conversion to 5-HPETE, what does 5LO create in it's second catalyzation? | 5-HPETE to Leukotriene A4 - the parent leukotriene
🗑
|
||||
| What must also be present to assist 5LO? | FLAP - 5-lipoxygenase activating protein
🗑
|
||||
| What are the two reactions of 5LO? | adds Ox to arachidic acid to make 5-HPETE
then, acts as endoperoxidas to remove water and create an double attached Oxygen, peroxy? which is Leukotriene, A4
🗑
|
||||
| What special trait does LTB4 exhibit? | Chemotactic, attracts immune cells to fight infections
🗑
|
||||
| What important antioxidant is needed as a substrate for LTA4 to convert to other actives such as LTC4, LTD4, LTE4 | glutathione via glutathion-S-transferase
🗑
|
||||
| What do LTC4 and LTE4 do? | peptidoleukotrienes - they are the actual bad ones - SRS-A's of astma and inflamation
🗑
|
||||
| What is important about omega-3 fatty acids in our diet? | They form eicosapentaenoic acid (EPA) prostaglandins and leukotrienes derived from them are less physiologically active - decreased inflammation etc..
🗑
|
||||
| What are the Series Number associated with prostaglandins and leukotrienes derived from arachadonic acid? | Prostaglandins = series 2
Leukotrienes = series 4
🗑
|
||||
| What are the Series Number associated with prostaglandins and leukotrienes derived from eicosapentanoic acid (EPA)? | Prostaglanidin = series 3
Leukotriene = series 5
🗑
|
||||
| What are the Series Number associated with prostaglandins and leukotrienes derived from eicosatrienoic acid (ETA)? | Prostaglandins = series 1
Leukotrienes= series 3
🗑
|
||||
| PGH2 synthase is a multifunctional enzyme with two active sites. What operates at each? | One = cyclooxygenase (COX)
Two = endoperoxidase
🗑
|
||||
| How are lipoxins different from other eicosanoids? | The are ANTI-inflammatory agents
🗑
|
||||
| How do we synthesize lipoxins? | 15-LO
🗑
|
||||
| Why do we still think of arachidonic acid in terms of inflammation if it also makes lipoxins? | Prostaglandin synthesis is greater than lipoxin synthesis.
🗑
|
||||
| How does aspirin over come the prostaglandin/lipoxin imbalance? | Aspirin is a suicide inhibitor of the PGH2 pathway. It ihibits COX 1 and COX2, but does not inhibit endoperoxidase at the second active site on PGH2-synthase. So 15-HPETE can make 15-epi-LXA4, which is a version of lipoxin.
🗑
|
||||
| What are aspirin-triggered epilipoxins? | enantiomers of 15S-HPETE formed when aspirin blocks the COX active site, but does not affect the endoperoxidase site on PGH2-synthatse
🗑
|
||||
| The pharmaceutical industry produces an agent that targets receptors How? | inhibit release of arachidonic acid from phosphatidyl insositol by steriods that block Phospholipase A.
🗑
|
||||
| What drugs target leukotriene action by inhibiting LTC4-receptors? | Montelukast (singular)
Zarfilukast (Accolate)
🗑
|
||||
| What drug inhibits 5-LO? | zileuton (Zyflo)
🗑
|
||||
| What drug inhibits FLAP | MK0886
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
El Diablo
Popular Biochemistry sets