UHCW 1

Bile acids: The Enigma of Emulsification ---

Getting Fat & Water to mix---

UHCW 2

Emulsifying fat--

Gift from Prof. Charles Stirling FRS

Toluene-SR

Water

Toluene: stained with Sudan Red to show the oil layer

UHCW 3

Emulsifying fat--

Gift from Prof. Charles Stirling FRS

Toluene: stained with Sudan Red to show the oil layer

Toluene-SR

Water

Toluene-SR

Water

Stearic acid

UHCW 4 Gift from Prof. Charles Stirling FRS

Toluene: stained with Sudan Red to show the oil layer

Emulsifying fat--

Toluene-SR

Water

Cholic acid

Toluene-SR

Water

Toluene-SR

Water

Stearic acid

UHCW 5 Gift from Prof. Charles Stirling FRS

Toluene: stained with Sudan Red to show the oil layer

Emulsifying fat--

Toluene-SR

Water

Cholic acid

Toluene-SR

Water

Toluene-SR

Water

Stearic acid

Water

Bile

Gift from Mr. Manfred Lambertz

UHCW 6 Gift from Prof. Charles Stirling FRS

Toluene: stained with Sudan Red to show the oil layer

Emulsifying fat--

Toluene-SR

Water

Cholic acid

Toluene-SR

Water

Bile

Toluene-SR

Water

Toluene-SR

Water

Stearic acid

Water

Bile

UHCW 7

“Hydrophilic” surface

“Hydrophobic” surface

--stays at the interface between water and air

Bile acids – and sailing boats??!!

UHCW

Gift from Prof K D Bardhan

8

BA in gut lumen: ~3g

BA daily need: ~12-36g

Fecal loss: ~600 mg daily

BA re-circulation

BA re-circulation 4-12 cycles / day

Bile acids: The journey

UHCW

Gift from Prof K D Bardhan & Dr M Smith

9

•  95-98% absorbed in

terminal ileum

•  Recirculated up to x 4-12 in 24 hours

BA

Bile acid absorption: In health

UHCW 10

Watery diarrhea

BA

• TI absorption reduced

• Excess unabsorbed BA spills into colon

• Interferes with calcium-mediated water & electrolyte absorption: Net fluid loss

Bile acid absorption: In malabsorption

UHCW

Gift from Dr M Smith

11 Normal retention at day 7 : ≥ 15%

SeHCAT

Test procedure • Uncollimated gamma camera • 5 minute AP, PA views and background

The SeHCAT retention test