AJP - Gastrointestinal and Liver Physiology, Vol 254, Issue 3 346-G354, Copyright © 1988 by American Physiological Society
Triton WR-1339-induced changes in serum lipids and biliary lipid secretion
M. Zeniya and A. Reuben
Liver Study Unit, Yale University School of Medicine, New Haven, Connecticut 06510.
Biliary lipid secretion rates were measured in fed rats after an
intravenous injection of Triton WR-1339 (TWR, 60 mg/100 g body wt), an
agent that inhibits lipoprotein removal from the circulation. Serum
triglyceride, phospholipid (PL), and cholesterol (CH) concentrations rose
within 3 h of TWR to 45, 6.6, and 10 times control values, respectively, at
24-36 h. Serum lipids fell rapidly at 48 h and were normal by 72-96 h after
TWR. TWR did not alter bile flow, hepatic bile acid transport, or biliary
bile acid output. Within 0.5 h of TWR, biliary PL and CH outputs fell
greater than 70%, and taurocholate-stimulated biliary PL secretion was
markedly reduced. Biliary PL and CH secretion rates were approximately 30
and approximately 40% suppressed, respectively, 24 h after TWR, 160 and
330% elevated, respectively, at 48 h, and normally by 72 h, despite normal
taurocholate-stimulated biliary PL secretion. Biliary beta-glucuronidase
secretion (a lysosomal enzyme) was unchanged for 3 h after TWR but was
increased at 24, 48, and 72 h, independent of biliary lipid secretion. Thus
TWR acutely dissociates bile acid from lipid secretion without impairing
bile acid transport or biliary lysosomal discharge. Late changes in biliary
lipid secretion relate closely to TWR-induced change in serum lipid
metabolism but not to stimulation of biliary lysosomal discharge.
