Changes of gastric lipase activity after ethanol and indomethacin administration: Influence of pretreatment with allopurinol, pentoxifylline and L-DOPA

Gastric lipase (GL) plays an important role in emulsification and digestion of food fat. Lipids are components of the hydrophobic mucus and mucosa bar rier. Damage of the gastric mucosa may therefore be related to changes in t he lipid content and GL activity. In the present paper, we studied the effe ct of administration of a single dose of 96 % ethanol (E) and indomethacin 20 mg.kg(-1) (IND) on the activity of GL and on the concentrations of nones terified fatty acids (NEFA) and triacylglycerols (TG) in the gastric mucosa of rats. Furthermore, we studied how these changes are affected by allopur inol (ALO), pentoxifylline (PX) and L-DOPA pretreatment 30 min before admin istration of E or IND. The effect of sialoadenectomy (SA) on these paramete rs was also evaluated. We found: 1) significant (p<0.01) inhibition of GL a ctivity after administration of E and IND and also ALO, as well as after pr etreatment with ALO before E and PX before IND. L-DOPA administered alone s timulated GL activity, but its administration before IND significantly (p<0 .01) inhibited this enzymatic activity. GL activity was decreased to the th reshold values in SA rats and after administration of E to SA animals, 2) N EFA concentrations were decreased after E and increased significantly (p<0. 01) after IND administration. A marked significant (p<0.01) decrease in NEF A was found after PX and L-DOPA administration. The administration of ALO a lso lowered the concentration of NEFA. Pretreatment by drugs before E and I ND resulted in a significant increase of NEFA in comparison with the drugs given alone (p<0.05 for ALO + E; p<0.01 for PX + IND). 3) TG were also decr eased in all experimental groups in comparison with the control group, i.e. after E and IND, after ALO and SA and also after pretreatment by ALO befor e E. The concentration of TG decreased after PX, significantly (p<0.05) aft er L-DOPA and after pretreatment by PX before IND. Pretreatment by ALO befo re E and L-DOPA before IND resulted in the increase of TG in comparison wit h drugs alone. Thus, these results suggest certain protective effect of pre treatment with ALO, PX and L-DOPA against the E- and IND-induced decrease i n NEFA and TG during injury of the gastric mucosa. On the other hand, inhib ition of GL activity was also apparent after administration of these drugs before E and IND, which suggest presence of a persisting impairment of lipi d digestion in the stomach.