Abstract
A Golgi complex rich-fraction containing both N-acetylglucosamine galactosyltransferase and kallikrein activity has been isolated from kidney of rats previously treated with colchicine, a secretion inhibitor, followed by the administration of high-sodium solutions, to stimulate biosynthesis or activation of renal kallikrein. After the treatment, N-acetylglucosamine galactosyltransferase and kallikrein activities were increased in the Golgi complex, about 18- and 24-fold, respectively, as compared to the homogenate. Low kallikrein activity was found in the crude light mitochondrial fraction from treated animals, whereas a high level of activity was observed in the microsomal fraction. The inverse situation was found in rats treated only with high-sodium solution. Results suggest that kallikrein is probably transported by microsomal elements, particularly by the Golgi complex. Furthermore, the evidence seems to indicate that the kallikrein activity reported in the plasma membrane and/or in the lysosomal fraction is due to kallikrein secretion, in the form of intact granules, which have sedimented with these two fractions.
