Effect oflysolecithin ongastric mucosal structure andpotential difference

SUMMARY Theeffect oflysolecithin (100mg%)on theguinea-pig gastric mucosa was studied by instilling a solution for30minutes, preceded andfollowed by100MN HC1into10total gastric pouches. Tencontrol animals hadHCIthroughout. Lysolecithin produced a significant change in transmucosal potential difference, macroscopic erosions, andmucosaldamageon histology andelectron scanning microscopy. Noneofthese changes was seeninthecontrol animals. Thisis further evidence that thereflux oflysolecithin fromtheduodenumisanimportant factor incausing active gastritis andgastric erosions. A number ofsubstances including bile salts, aspirin, andlysolecithin havebeenfoundtobreakthe gastric mucosal barrier andproduce sodium and hydrogen ionfluxacross themucusmembrane. When Davenport (1970) first performed these studies hedidnotcorrelate thechemical changes with structural damage tothegastric mucosa. Thepurpose ofthepresent investigation wastomeasure changes inthetransmucosal potential difference (TMPD) atthesametimeasstudying changes shownby light microscopy andscanning electron microscopy (SEM). Lysolecithin, aphospholipid produced by theaction ofthephospholipase inpancreatic juice onthelecithin inbile, iswell knowntodamage cell membranes. We havefoundthis substance inhigh concentrations inthenight gastric juice ofpatients withgastric ulcer butnotinnormal subjects (Johnson andMcDermott, 1974). These concentrations were similar tothose that Davenport hadfound tobreak thegastric mucosal barrier, andwe therefore thought itimportant toseewhether lysolecithin alsoproduced structural damage ofthemucosa.