Unscheduled DNA synthesis in human leucocytes after a fish (amine source) meal with or without salad (nitrite source)

Increased unscheduled DNA synthesis (UDS) was observed previously in leucocytes from human volunteers after various meals containing nitrite from cured meats and vegetables. To explore further the role of ingested nitrite, UDS response was measured in human leucocytes after a meal of bread, butter and cod fish alone (amine source) or bread, butter and cod fish plus a salad of lettuce, radish and spinach (nitrite source). A cross-over design was used so that all subjects (10 male, 10 female) were tested after both meals. Salad (nitrite source) had no effect on the level of UDS after the meal; however, UDS increased after the meal with or without salad for trial 1, but decreased for trial 2. The difference between trials could not be accounted for by sources of variation such as differences between individuals or experimental technique. The factor(s) responsible for this significant difference between trials must be associated with the non-salad components of the meal.