Effects of castration and testosterone on Fel dI production by sebaceous glands of male cats: I--Immunological assessment.

Fel dI is produced by salivary and sebaceous glands. Hormonal control of sebum production is clearly established. The influence of cat castration and supplementary treatment with testosterone on the production of sebum and Fel dI in cat skin have been researched in this study. On day 1, 12 male cats were anaesthetized and three skin areas carefully shaven. Then the level of lipids on skin surface was measured by means of a photometric method. Finally, the three areas of skin were washed with 5ml of distilled water through a plastic cylinder. Fel dI collected in the washes was measured with a two-site monoclonal antibody based ELISA. On day 2, six cats were castrated, the other six were used as a control group. Two and 4 weeks later, the levels of lipids and Fel dI in skin washes were measured again in all cats. On day 30, the six castrated cats were injected intramuscularly with prolonged-action testosterone. Two weeks later, quantification of lipids and Fel dI in all animals was repeated. Sebum and Fel dI levels decreased in all castrated animals. Injecting the castrated cats with testosterone led to a significant increase in sebum and Fel dI production. Our findings indicate that Fel dI production is influenced by the production of hormones.