VIP-, substance P-andmet-enkephalin- immunoreactive innervation ofthehuman gastroduodenal mucosaandBrunner's glands

on whole mounttissue preparations. A denseVIP-containing nervesupply was foundaround fundic and pyloric glands, whilethefewandscattered substance P-immunoreactive fibres tended torun acrossthefull thickness ofthegastric mucosa.Intheduodenum, bothVIPandsubstance Pwere present inastriking nervenetwork inthevilli aswell asinthemuscularis mucosae andaround blood vessels. Bothpeptides were alsoimmunostained innervebundles andneuronal perikarya between thelobules ofBrunner's glands, whileonly veryfewfibres reached theproximity of acinar cells. Met-enkephalin-immunoreactivity was detected ina small numberofnervefibres, virtually confined tothebasal partsofthemucosa andtotheduodenal submucous plexus. Several regulatory peptides areknowntobepresent innervous structures inthemammalian gut.Of these, VIP,1 substance p2andenkephalin3 have beendemonstrated inthehuman. Wehaverecently studied indetail thedistribution ofnervefibres immunoreactive forthese three peptides inthehumanlowergutmucosa, using microdissected andwholemounted tissue preparations.4 Wereport hereasimilar investigation onthe proximal humangut.Inviewoftherich supply of