THE EFFECTS OF ALUMINUM, IRON, CHROMIUM, AND YTTRIUM ON RAT INTESTINAL SMOOTH-MUSCLE IN-VITRO

The modification of peristaltic activity in the presence of several me tal ions has been investigated in the rat intestine by the isolated or gan technique. The metals tested modify the intestinal movements: alum inum, chromium, and yttrium cause a decrease of amplitude, while iron showed no effect. By use of microscopic techniques, the presence of yt trium hydroxide was observed in the intestinal tissues. Iron also appe ars as a precipitate outside of the intestinal serosal, which may expl ain why iron did not modify the peristaltism. Chromium and aluminum we re not apparent to microscope, despite being detected and quantified i n the tissues by means of atomic emission spectrometer. We conclude th at the trivalent ions of these elements may operate differently on the mechanisms of intestinal contractions: yttrium precipitates in interc ellular spaces, iron precipitates outside the intestines, and chromium and aluminum remain in solution and are distributed homogeneously in the smooth intestinal muscle.