Lecture 14 - Lactation Part 2 Flashcards
Why does the mammary epithelium have a high mitochondrial density
ATP for synthetic processes
Uptake precursors, transport into lumen
How much arterial blood oxygen does the mammary epithelium consume
50%
What does the rough endoplasmic reticulum of the mammary epithelium do
Make proteins (ribosomes)
What do the smooth endoplasmic reticulum of the mammary epithelium do
Make phospholipids and triglycerides (fat droplets)
(f.a. synthesis and glycolysis in cytosol)
What does the golgi do in mammary epithelium
Synthesizes lactose
Lactose synthase = glucose+galactose
Where does glucose for lactose synthesis come from
Starch and sugar digestion/absorption in monogastrics
Ruminants main source is propionate and glucogenic aa converted in the liver
Where does galactose for lactose synthesis come from
Conversion of glucose
The main determinant of milk secretion is
Lactose
Decrease in blood glucose leads to
Decrease of lactose and milk volume
What turns on the enzymes for lactose production
Prolactin
Milk fat is made up mostly of
98% triglycerides
How does the mammary get free fatty acids
From chylomicrons or VLDL
OR de novo f.a. synthesis in alveolar epithelial cells
Fatty acids can be made from… (monogastric vs ruminant)
Glucose, acetate and ketone bodies
NOT glucose in ruminants (saved for making lactose)
What happens to large lipid droplets? What else do these provide the neonate?
They are drawn to the apex of the cell
provide phospholipids, cholesterol to neonate
Slide 16**
Fats
What can non-ruminants do with regards to acetyl coa that ruminants can not
Can lyse citrate with citrate lyase in presence of CoA to produce acetyl-CoA for f.a. synthesis (make f.a. from glucose)
Ruminants do not have citrate lyase
What f.a. are in milk
C4, C6, C8, C10, C12