Term
| Where are prostaglandins distributed in humans? |
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Definition
| reproductive tract, seminal vesicles, menstrual fluid, umbilical cord, placenta |
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Term
| Where are prostaglandins distributed in animals? |
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Definition
reproductive tract, seminal vesicles, menstrual fluid, umbilical cord, placenta
and brain, spinal cord, ovary, uterus, renal medulla, pancreas, intestines, thymus, lung |
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Term
| Where are prostaglandins distributed in plants? |
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Definition
None – only fatty acid precursor, i.e. arachidonic acid
They don't have enzymes to make PG |
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Term
| Where are prostaglandins distributed in marine organisms? |
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Definition
Only found in coral (sea whip)
PGA2 is fully produced and is harvested by humans (within legal limits) and can be converted to all other prostaglandins |
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Term
| How are prostaglandins manufactured? |
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Definition
| 10% of gotgonian coral is prostaglandin A2, they are then made into other semi-synthetic PGs |
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Term
| What is the starting molecule in PG synthesis? |
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Definition
Prostaglandins are derived STRUCTURALLY from prostanoic acid (C-20 with 5-ring)
BIOSYNTHETICALLY they are derived from arachidonic acid (C-20 with 4 double bonds) |
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Term
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Definition
| PG stable in acid, keto group C-9 and double bond between 10 and 11 |
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Term
| What are the most common PGs? |
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Definition
PGE (Keto at 9 and OH at 11)
and PGF (OH at 9 and 11), alpha or beta refer to OH orientation at 9 (alpha is below plane) |
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Term
| What does a number, such as PGA2, indicate in PG nomenglature? |
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Definition
| The number of double bonds at the side chain |
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Term
| What is a major distinguishing trait of PG chains? |
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Definition
| There is ALWAYS an -OH group at carbon 15. |
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Term
|
Definition
| Bioactive oxidative metabolites of 20 x carbon fatty acids: e.g. PGs, leukotrienes, thromboxanes, prostacyclin |
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Term
| What PG is the precursor to PGD, E, F, I, and TX? |
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Definition
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Term
| What is the chemical role of COX? |
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Definition
| To convert arachidonic acid into PGs, by introducing oxygen into the compound and cyclizing a 5-ring structure |
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Term
| Why is metabolism of PG really fast? |
|
Definition
The C-15 OH that is next to a double bond (allylic OH) is very unstable and is readily oxidized to a keto
Also, C-13 and 14 bond reduced
Minor:
Beta-oxidation (release 2 carbons)
Omega-oxidation (oxidation at methyl end of alkyl side chain) |
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Term
| Describe prostacyclin structure |
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Definition
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|
Term
| How do we increase half-life of PGs? |
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Definition
| Add a methyl group at C-15 to prevent metabolic oxidation |
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Term
| What is the difference between COX1 and COX2? |
|
Definition
A single amino acid at site of activity
COX 1- isoleucine
COX 2- valine
COX2 only drugs don't fit with the larger isoleucine |
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Term
| What is the precursor to all steroids and cardiac glycosides? |
|
Definition
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|
Term
| Describe the structure of estrane (precursor of estrogen steroids) |
|
Definition
|
|
Term
| Describe the structure of androstane (precursor of androgen steroids) |
|
Definition
|
|
Term
| Describe the structure of pregnane (precursor of progesterone steroids) |
|
Definition
|
|
Term
| What is the differnce between alpha and beta steroids? |
|
Definition
Alpha are trans
Beta are cis
All known are trans except estranes and cardiac glycosides |
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Term
| What is the first intermediate in synthesis of mineralo/glucocorticoids from cholesterol? |
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Definition
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|
Term
| How can estrogens be differentiated from all other steroids? |
|
Definition
| An aromatic, phenolic A ring |
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|
Term
| What enzyme converts glucocorticoids to mineralocorticoids? |
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Definition
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