The influence of limonene on induced delayed hypersensitivity to citral in guinea pigs. II. Label distribution in the skin of 14C-labelled citral

14C-labelled citral was applied on four groups of guinea pigs: (a) one sensitized to citral alone; (b) one sensitized to a citral-d-limonene 1 : 1 molar mixture; (c) FCA-treated controls; (d) controls. The most important results concern the amount of labelled material in soluble compared with insoluble skin protein extracts (SPE). In citral-sensitized animals, more label was found in the soluble SPE when citral + limonene was applied to the skin; in citral + limonene sensitized animals, the same trend (i.e. more label in soluble SPE) was found. The possible role of limonene in alleviating the allergic reaction to citral is discussed.