[Enzyme histochemical diagnosis of gastrointestinal motility disorders. A laboratory guide]

The enzyme histochemical reactions for acetylcholinesterase, lactic dehydrogenase, succinic dehydrogenase and nitroxide synthase are currently the gold standards for the diagnosis of gastrointestinal motility disorders. The acetylcholinesterase staining reaction shows the cholinergic nerve fibre network of the muscularis mucosae and muscularis propria, and correlates with their acetylcholinesterase activity. Lactic dehydrogenase, succinic dehydrogenase and nitroxide synthase selectively demonstrate the nerve cells of the myenteric and submucous plexus. These enzyme histochemical techniques require fresh, native tissue. Consequently, the transport of biopsies from gastroenterology or surgery to pathology must be well organized and feasible without time loss. Alternatively, biopsies may be mailed on dry ice to more distant pathology institutes. The enzyme histochemical laboratory technique has been optimized and refined over four decades. The optimized reactions are highly reliable and reproducible. In particular, a standardized methodology is a prerequisite for the interinstitutional comparability of results. This laboratory manual provides a detailed methodological description of the most important enzyme histochemical reactions for the diagnosis of gastrointestinal motility disorders.