The effects of acute and chronic administration of n-6 and n-3 polyunsaturated fatty acids on ethanol-induced gastric haemorrhage in rats.

Female weanling rats in three equal groups (n 12) were given orally by intubation 1 ml micellar solution of taurocholic acid (10 mM) and either arachidonic acid (20:4 n-6), linoleic acid (18:2 n-6) or eicosapentaenoic acid (20:5 n-3) at a concentration of 120 mM. After 1 h the rats were given intragastrically 2 ml absolute ethanol and were killed 1 h later. Rats given oral 20:4 n-6 showed a significant reduction (P less than 0.05) in the extent (%) of gastric mucosal haemorrhage compared with either the rats given 20:5 n-3 or 18:2 n-6 (8.3 (SD 7.3), 23.2 (SD 10.4) and 21.4 (SD 10.4) respectively. In a second experiment, four equal groups (n 12) of female Wistar rats were fed for 5 weeks on either a control diet of standard laboratory rat food, or the same diet enriched with either maize oil or fish oil or butterfat at a level of 100 g/kg. Following a 24 h fast the rats received an intragastric dose of 2 ml ethanol and were killed 1 h later. Examination of the extent (%) of gastric lesion showed a significant reduction (P less than 0.05) with the feeding of either maize oil or fish oil compared with the controls (12.2 (SD 8.2), 15.3 (SD 13.2) and 29.3 (SD 14.0) respectively). The butterfat diet was not significantly different from the control diet (23.8 (SD 8.1)).