The effect of BaCl2 on intestinal sugar transport in the rat in vitro.

The effect of BaCl2 on galactose transport across isolated rat small intestine has been investigated. The addition of 5 mM BaCl2 or theophylline (3 mM) to the bathing solutions increased cell water free sugar accumulation and decreased mucosal to serosal sugar fluxes. However the effects of BaCl2 were smaller than those induced by theophylline. Removal of Ca2+ from the bathing solutions did not modify the response to BaCl2, though the response to theophylline was partially reduced. In the presence of 0.1 mM trifluoperazine, both theophylline and BaCl2 were without effect on sugar transport. These findings are discussed in terms of an effect of Ba2+ on intestinal smooth muscle tone.