A comparison by species, age and sex of cysteinesulfinate decarboxylase activity and taurine concentration in liver and brain of animals.

Cysteinesulfinate decarboxylase activity and taurine concentration were determined in liver and brain of rats, mice, cats, guinea-pigs and sheep. Values were compared for male and female animals and in some cases measurements were also made in animals of different ages. Cysteinesulfinate decarboxylase activity and taurine concentration were also measured in liver and brain of male and female rat pups during the postnatal period. Hepatic cysteinesulfinate decarboxylase activity increased in both male and female rat pups during the postnatal period and then declined markedly in female rats so that activity in adult males was 16-fold that in adult females. Cysteinesulfinate decarboxylase activity in liver of 5- to 6-week old kittens was 73 times that observed in liver of 15-month old cats. Taurine level in liver of guinea-pigs was much lower than that in liver of any other species studied.