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The influences of protarnine on Na6, K6-dependent ATPase and active transport processes of potassium and L-dopa into brain cortex slices of guinea pig were examined. Addition of protamiile to the soluble ATPase preparation extracted from brain inicrosomes resulted in the formation of a precipitate, Protamine slightly stimulated the activity of the Na+, K+-dependent ATI'ase in the soluble and microsolnal preparatioi~s from the guinea pig brain. However, pretreatment of the ATPase preparations with protatnine a t 37 "C or 45 "C resulted in a loss of Na+, K+-dependent ATPase activity, though the activity of Mg++-ATPase was not iinfluenced. These effects s f protamine on the Na+, K*-dependent ATPase were antagonized by the presence of cations.Active transport of potassium and of L-dopa into the slices was decreased by pretreatment of the slices with protamine in sucrose nnedium a t 37 "C. However, a t a low temperature or irr Ringer solutioll there was no remarkable effect. The role of Na' , K+-dependent ATPase in the active transport of potassium and of L-dopa is discussed on the basis of these results.

Recently, Sharman and Vogt (1) reported that it was not possible to confirm that the caudate nucleus of the rabbits had the high noradrenaline content (0.85 ug/g) reported by Matsuoka et al. (2) from our laboratory.Sharman and Vogt compared three different methods, and found that there was less than 0.045 lig/g noradrenaline in the caudate nucleus of the rabbit. They suggested that the high noradrenaline content we had previously found was due to contaminants adsorbed on the strongly cationic exchange resin column used and converted to fluorecent compounds with ferricyanide. This prompted us to reinvestigate on this subject carefully. Groups of 5 rabbits weighing 1.8-2.3 kg were sacrificed under Nembutal anesthesia. About 300 to 400 mg of caudate nucleus was obtained from each group and this was homogenized with 0.4 N perchloric acid. The catechol com pound extracted by perchloric acid were purified by adsorption onto aluminum hydroxide. Neutral and basic catechol compounds were then adsorbed on a Duolite C-25 resin column (0.4 x 4.0 cm).Dopa, noradrenaline and dopamine were eluted separately with 4.0 ml of 0.35 N sodium acetate buf fer (pH 5.0), 2.0 ml of 3.0 N sodium acetate buffer (pH 6.0) containing 7% ethanol and 2.0 ml of 3.0 N sodium acetate buffer (pH 6.0) containing 25% ethanol, respectively. The eluate containing nor adrenaline was divided into three portions which were used for the blank, the sample and the standard, and the noradrenaline content was estimated by a modification of the trihydroxyindol method. The blank was prepared by addition of the same amount of ascorbic acid as used for the sample after "faded" with ferricyanide and sodium hydroxide. Fluorescence was measured in a Farrand spectrophotometer.Overall recovery was about 60%. The noradrenaline concentration in the caudate nucleus of the rabbit was found to be 0.0608+0.0236 pg/g (Mean±S.E.) in four experi ments. The discrepancy of this result with our previous report seems to be because in the present work catechol compounds were.purified by aluminum hydroxide treatment and this removed some contaminants. biophys. acta 82, 439 (1964)

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