Uptake of bile acids into rat intestine. Effect of diabetes mellitus.

Diabetes mellitus is associated with the enhanced uptake of several nutrients. The purpose of this study was to use an established in vitro technique to examine the uptake of bile acids into jejunum, ileum, and colon of control (CON) and streptozotocin-diabetic rats (DM). When the bulk phase was stirred to reduce the effective thickness of the unstirred layer, the ileal uptake of 1.5-15 mM cholic (C), glycocholic (GC), taurocholic (TC), chenodeoxycholic (CDC), glycochenodeoxycholic (GCDC), and deoxycholic (DC) acid was similar in CON and DM. The relative values of the maximal transport rates (Jdm) were CDC greater than GC greater than GCDC greater than C greater than TC = DC, and similar relative values were observed for the Michaelis constants (Km). The values of Jdm and Km for each bile acid were similar in CON and in DM. In CON and at pH 7.4 an inverse linear relationship was noted between the number of hydrogen bonds in the bile acids and the natural logarithm of the permeability coefficient (Pd) times the square root of the molecular weight of the bile acid. This slope reflected the incremental change in free energy, delta delta Fw leads to I, associated with the uptake of bile acids; the value of delta delta Fw leads to I was similar for jejunum, ileum, and colon of CON, but was lower in jejunum of DM than CON. Thus, DM is associated with a greater relative permeability of the jejunum but not the ileum or the colon to a series of bile acids.(ABSTRACT TRUNCATED AT 250 WORDS)