Lysophosphatidylcholine potentiates the increase in mucosal permeability after small-intestinal ischaemia

The influence of lysophosphatidylcholine (lysoPC), taurodeoxycholate (TDC), and taurochenodeoxycholate (TCDC) on the permeability properties of the ischaemic small-intestinal mucosa was investigated. We first studied the effect of ischaemia alone, then of lysoPC, TDC, or TCDC alone, and finally of ischaemia together with lysoPC, TDC, or TCDC on the permeability to sodium fluorescein in a ligated loop of the distal ileum in the rat. Longer periods of ischaemia alone (10 min or more) caused increased permeability, as did high concentrations (10 mM) of any of the agents. Low concentrations (1 mM) of lysoPC alone did not alter the gut permeability, but it significantly potentiated the increased permeability caused by 30 min of ischaemia. In contrast, 1 mM TDC or TCDC did not influence the permeability after 30 min of ischaemia. These findings imply that the ischaemic small intestine may be damaged by small amounts of lysoPC, with increased absorption of potentially pathogenic compounds as a possible consequence. They also point to the possibility that endogenously formed lysoPC may play a role in the mucosal damage and the increased permeability that occurs after small-intestinal ischaemia.