Fig. 3. Determination of KAT I, KAT II and KAT III activity in human saliva. Twenty-four human saliva samples were used. Data represent the mean ± SEM. Data are expressed in femtomole of KYNA formed per microlitre of saliva per hour (Fig. 3A) and in picomole of KYNA formed per milligram of protein per hour (Fig. 3B).