Role of diets in modifying gastrointestinal neurotransmitter enzyme activity

Manipulation of diet, by altering the composition or quantity, can produce alterations in the central nervous system as evidenced by changes in memory or behavior. The present study was designed to examine the effects of fasting/starvation or a choline deficient diet on the enzymes that synthesize and degrade acetylcholine and norepinephrine, both neurotransmitters in the gastrointestinal tract. This study was conducted on three groups of male rats: control nontreated, choline deficient diet for 14 days, and fasting/starvation (water only) for 3 days. Enzyme activities were determined throughout the length of the gut. The lack of dietary choline produced a decrease in adrenergic enzyme activity but had little effect on cholinergic enzyme activities. Starvation decreased adrenergic enzyme activities and increased activity of the acetylcholine synthesizing enzyme in most segments of the gastrointestinal tract. Starvation was also a stressor, as evidenced by elevated levels of plasma and adrenal corticosterone. The implication from these experiments is that dietary manipulation may produce functional changes (i.e., motility and secretion) in the gastrointestinal tract as a result of altering neurotransmitter enzyme activities.