Detoxification of Xenobiotics Flashcards
Which layer of the adrenal cortex produces aldosterone?
Zona glomerulosa
Which layer of the adrenal cortex produces cortisol?
Zona fasciculata
Which layer of the adrenal cortex produces androgens?
Zona reticularis
What are Xenobiotics?
Any compound that is foreign to the body
What is the primary function of the detox systems?
Make the compound more soluable, since they are most often lipid like
What is the chief reaction in Phase I detox system?
Hydroxylation
Cytochrome p450s are ….
Monooxigenases
What are mono-oxygenases?
Group of hemeproteins
What does phase I use as a source of electrons?
NAPDH (pentose pathway)
FAD (ETC)
What are the vitamins involved in Phase I detox?
Niacin, riboflavin, iron
How does the phase II detox system increase water solubility?
By attaching hydrophilic groups onto the xenobiotic
What are the primary reactions in phase II detox?
Conjugation reactions
What are the 6 phases of phase II detox?
Glutathionation, glucuronidation, addition of aa, acetylation, sulfation, methylation
What are the 3 kinds of glucuronidation?
O, N, S
Glucuronidation adds onto which carbon?
C6
O-glucuronidation uses what enzyme?
UGT
Which step of phase II is most like cholesterol?
Addition of aa– bile acid plus taurine or glycine
What is the primary purpose of the acetylation step of phase II?
Reduce the activity of the amino group conjugate in the 3rd step through masking.
What is the function of the sulfation step of phase II?
Transfer activated sulfur group
Does methylation improve solubility?
No, acts as a masking group
What is an example of methylation important in the body?
SAM + NE to Epinephrine
Where does the methyl group need to be added to NE to activate into epinephrine?
NH group
When the methyl group adds to the carboxyl end, what is it called?
3-methoxynorepinepherine (inactive)
What tissues are most important in detoxification reactions?
Liver (primary), lungs, adrenals, gut
Where are the enzymes found in the cells for detox?
sER, mitochondria
