activity in the gut.pdfVIP

Gut, 1972, 13, 790-795 Noradrenaline concentration and turnover in different regions of the gastrointestinal tract of the rat: an approach to the evaluation of sympathetic activity in the gut H. L. TAUBINI, B. DJAHANGUIRI, AND L. LANDSBERG with the statistical analysis by E. LERNER From the Catecholamine Laboratory, West Haven Veterans Hospital, West Haven, Connecticut, and the Departments of Medicine (Section of Gastroenterology) and Pharmacology, Yale University School of Medicine SUMMARY The endogenous noradrenaline concentration, fractional turnover, half-life, and turn- over rate of tritiated (3H) noradrenaline were determined in the oesophagus, non-glandular and glandular portions of the stomach, duodenum, jejunum, ileum, and colon of the rat. The highest concentration of endogenous noradrenaline was present in the duodenum and colon. The 3H- noradrenaline fractional turnover rates and half-lives were significantly greater in the small and large intestines as compared with the oesophagus and stomach. The noradrenaline turnover rate, which is an estimate of the level of sympathetic activity, was greatest in the colon and duodenum. This method of assessing sympathetic activity in various tissues by direct measurement of the noradrenaline turnover rate may be applied to the study of the adrenergic nervous system in the physiology and pathophysiology of the gastrointestinal tract. The influence of the sympathetic nervous system on gastrointestinal function has long been the subject of investigation. Information about the sympathetic innervation of the gastrointestinal tract has ac- cumulated gradually from diverse techniques such as nerve sectioning and nerve stimulation, the appli- cation of autonomic agonists and antagonists, and the preparation of histochemical stains specific for neurotransmitters. Nevertheless, the role played by the adrenergic nervous system in normal physio- logical mechanisms of the gut is poorly understood. Even more obscure is the contri