[Studies of the presence of enzymes in various tissues of swine. 4. Studies of the Ca-, Mg-, and Na-K-ATPase activities in the homogenate and cell fractions of brain of fetuses and piglets].

Studies were conducted into the activities of calcium, magnesium, and sodium-potassium ATPase as well as into crude protein levels in homogenate and cell fractions of brain of two foetuses, aged 111 days, and of two piglets each, aged two days or nine weeks. The average brain-borne crude protein percentages were 6.55 in the foetuses, 7.25 in the two-day piglets, and 9.60 in the nine-week piglets. Calcium, magnesium, and sodium-potassium ATPase activities, related to one gram of fresh brain mass, were found to go up along with growing age. Highest relative percentages of sodium-potassium ATPase were recordable from homogenate and from the mitochondrial and microsomal fractions of the foetuses. Certain quantitative differences were obtained from using calcium, magnesium, sodium, and potassium ions to stimulate ATPase in the fractions of cell nuclei, mitochondria, and microsomes. The optimum temperature for magnesium and sodium-potassium ATPase in homogenate and in the mitochondrial fraction of brain was 45 degrees C.