FELININE - A URINARY AMINO-ACID OF FELIDAE

Felinine (2-amino-7-hydroxy-5,5-dimethyl-4-thiahe acid) has been ident ified in the mine of several members of the Felidae family including t he cat (Felis catus). Rates of excretion of 95 mg/day have been record ed for entire male cats with entire female cats excreting around 19 mg /day. These high excretion rates in entire male cats may have a signif icant effect on the daily sulphur amino acid requirement. The isoamyl moiety of felinine seems to originate from the same isoprenoid pool as used for the synthesis of cholesterol in the cat. The sulphur in the felinine molecule appears to originate from cysteine, although some co ntradictory evidence exists. The site of synthesis and the method of t ransportation in the blood remain largely unknown. The biological sign ificance of felinine to the animal is still a matter for speculation, but its function as a precursor to a pheromone seems likely. Recently, an accurate chemical assay for felinine has been developed that will allow investigation of felinine in different tissues and excretions an d from a wider range of mammals.