Distribution of cat allergen 1 in cat tissues and fluids.

The distribution of the major allergen of the domestic cat, cat allergen 1, was studied in 22 different tissues obtained from a male and female cat and in samples of saliva and urine. Of the cat tissues studied, only extracts of pelt and female brain contained amounts of cat allergen 1 in excess of 0.50 U/ml. Smaller amounts of cat allergen 1 were found in extracts of eye, thyroid, ovary, sublingual gland and large intestine. Unstimulated cat saliva contained a mean of 1.08 U/ml cat allergen 1. Saliva stimulated with ketamine HCl alone, or with ketamine HCl plus pilocarpine, contained 0.68-8.16 U/ml cat allergen 1. In all of the stimulated saliva collections, the total quantity of cat allergen 1 obtained was relatively constant (between 40 and 80 U). These results suggested that the elaboration of cat allergen 1 in saliva is independent of parasympathetic control. Cat allergen 1 could only be detected in cat urine that had been concentrated 9-fold in concentrations of less than 0.5 U/ml. The above results support the hypothesis that the major source of cat allergen 1 is the saliva, and that the presence of cat allergen 1 in the pelt is due to deposition of the allergen during grooming.