Foreword
REGULATION OF KETOGENESIS
(Sung to the tune of “Clementine”)In starvation, diabetes, sugar levels under strain
You need fuel to keep going saving glucose for your brain
Ketone bodies, Ketone bodies, both acetoacetate
And its partner on reduction, 3-hydroxybutyrate.
Glucagon’s up, with low glucose, insulin is down in phase
Fatty acids mobilised by hormone-sensitive lipase
Ketone bodies, Ketone bodies, all start thus from white fat cell
Where through lack of glycerol-P, TG making’s down as well.
Fatty acyl, CoA level, makes kinase phosphorylate
Acetyl-CoA carboxy-lase to its inactive state
Ketone bodies, Ketone bodies, because glucagon they say
Also blocks carboxylation, lowers Malonyl-CoA.
Malonyl-CoAs a blocker of the key CPT-
Blocking’s off so now the shuttle into mito’s is begun
Now we’ve ß oxidation, now we’ve acetyl-CoA
But what’s to stop it’s oxidation via good old TCA?
In starvation, glucose making, stimulating PEP CK
Uses oxaloacetic, also lost another way
Ketone bodies, what is odd is that the oxidation state
Also favours the reduction of OA to make malate.
OA’s low now, citrate synthase, thus loses activity
So the flux into the cycle cuts off (temporarily)
Ketone bodies, Ketone bodies situation thus is this
Acetyl-CoA’s now pouring into Ketogenesis.
It’s a tricky little pathway, it’s got HMG-CoA
In effect it’s condensation in a head-to-tailish way
Ketone bodies, Ketone bodies, note the ratio of the pair
Is controlled by NAD to NADH everywhere.
Don’t despise them, they’re good fuels for your muscles, brain and heart
When you’re bodies overloaded though, that’s when your troubles start
Ketone bodies, ketone bodies, make acetone, lose CO
You can breath those out, but watch out - acidosis does for you!
© “The Biochemists’ Songbook, 2nd ed.” Harold Baum. London: Taylor and Francis Publishers,
- Used with permission.