. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 618 MIROSLAV CESKA AND JAMES R. FISHER 4-day embryos, as was done with area vitellinu and area vitellina endoderm. It was found that heart from 21-day embryos does not exhibit arginase activity and inhibits 4-day embryo arginase (Fig. 3). As in the case of vitellina and vitellina endoderm, dialysis for 4 clays in the cold against distilled water increases the in- hibitory activity of heart homogenate (Fig. 3). Heart from 6-week-old chickens also inhibits 4-day embryo arginase. Results obtained show this inhibition when enzym
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 618 MIROSLAV CESKA AND JAMES R. FISHER 4-day embryos, as was done with area vitellinu and area vitellina endoderm. It was found that heart from 21-day embryos does not exhibit arginase activity and inhibits 4-day embryo arginase (Fig. 3). As in the case of vitellina and vitellina endoderm, dialysis for 4 clays in the cold against distilled water increases the in- hibitory activity of heart homogenate (Fig. 3). Heart from 6-week-old chickens also inhibits 4-day embryo arginase. Results obtained show this inhibition when enzyme is activated with 5 X 10~- or 5 X 10'* M Mn++. In order to directly demonstrate the presence of inhibitor(s) in a tissue which exhibits arginase activity, it is necessary to destroy its arginase activity before testing against 4-day embryo arginase. It is known that dialysis inactivates. UNDIALYSED Q Q DIALYSED T _^____^____^^^_^_^_ 80 120 160 200 MGS. HEART/ML. REACTION MIXTURE FIGURE 3. Effect of 21-day embryo heart homogenate on the arginase activity of 4-day embryo (15 mg. per ml. reaction mixture). Dialysis was carried out for 4 days in the cold against distilled water. arginase (Greenberg, 1951). We have confirmed this observation, using partially purified beef liver arginase which was obtained commercially. Activation with Mn++ under the conditions we are using does not restore activity. We have destroyed the arginase activity of several tissue homogenates in this manner and tested the dialyzed homogenates for inhibitor activity, using 4-day embryos as a source of arginase activity. It was observed that homogenates of bone marrow, skin, leg muscle, eye and brain from 21-day embryos can completely inhibit the arginase activity of 4-day embryos. The effect of dialyzed brain homogenate is shown in Figure 4. These results clearly show that all tissues tested contain arginase inhibitor (s), if the only effect of dialysis is to inactivate arginase. The observation was made w
Size: 923px × 2707px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
