Difference in the effects of ursodeoxycholate and its taurine conjugate on the biliary excretion of sulfobromophthalein in the rat.
A simultaneous intravenous infusion of sulfobromophthalein (BSP) (0.3 mg.min-1.100 g-1) and ursodeoxycholate (UDC) or tauroursodeoxycholate (TUDC) (1.2 mumol.min-1.100 g-1) caused a significantly higher excretion rate of BSP than in the control value without bile salt infusion. In UDC-infused rats, however, the BSP excretion rate began to fall rapidly within the first 30 min of infusion, while the bile flow rate remained high, or even continued to increase. In contrast, the BSP excretion rate in TUDC-infused rats was stable up to 60 min and then began to decline in parallel with the fall of bile flow rate. A significant increase in the BSP transport maximum (Tm) induced by UDC and TUDC in rats does not agree with a previous observation in hamsters where neither of these bile salts enhanced BSP Tm. The discrepancy between these two studies can best be explained by the poor biliary excretion of either TUDC or UDC in hamsters as was previously reported. It was concluded that in rats both TUDC and UDC can significantly increase BSP Tm, which paralleled the excretion rate of bile salts and not the bile flow rate.
Kanai
S
S
First Laboratory of Clinical Physiology, Tokyo Metropolitan Institute of Gerontology, Japan.
Kitani
K
K
Sato
Y
Y
D000818:Animals; D001646:Bile / Q000378:metabolism*; D003840:Deoxycholic Acid / Q000031:analogs & derivatives*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013448:Sulfobromophthalein / Q000493:pharmacokinetics*; D013654:Taurine / Q000494:pharmacology*; D014580:Ursodeoxycholic Acid / Q000494:pharmacology*
C030141:taurine-ursodeoxycholate conjugate; D003840:Deoxycholic Acid; D013448:Sulfobromophthalein; D013654:Taurine; D014580:Ursodeoxycholic Acid