The stomach does not absorb many substances. One of the few macronutrients that the stomach is able to absorb is ethanol, the intoxicating substance in fermented and distilled liquors. Only a small amount of ethanol passing through the stomach is absorbed, and this absorption is facilitated by an enzyme, alcohol dehydrogenase, which is secreted by the gastric wall, and by the liver in significantly larger amounts. Alcohol dehydrogenase converts ethanol into acetaldehyde, which is then further modified to produce acetate and other molecules utilizable by cells. Ethanol that is not broken down and absorbed in the stomach continues passing through the gastrointestinal tract, with most of it being absorbed into the bloodstream at the large intestine. The substance circulates in the blood until it is processed by the liver.

The cytoskeletal F-actin network was targeted in a sample of the fundus region of a rat stomach (presented above) with phalloidin conjugated to Alexa Fluor 568. Phalloidin is a member of the phallotoxin group of bicyclic peptides isolated from the deadly Amanita phalloides mushroom. The tissue section was also labeled for nuclear DNA with Hoechst 33342 and the Golgi complex with Oregon Green 488 conjugated to wheat germ agglutinin (WGA). Images were recorded in grayscale with a 12-bit digital camera coupled to a Nikon Eclipse 80i microscope equipped with bandpass emission fluorescence filter optical blocks. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.