High Molecular Weight Renin in the Mouse Kidney

Abstract

This study was conducted to determine whether or not high molecular weight renin is present in the mouse kidney. The molecular weight of renin in the cytosol fraction of mouse kidney cortex was approximately 40000 as determined by gel filtration. Renin in this fraction was partially converted into high molecular form (54000) in the presence of sodium tetrathionate or N-ethylmaleimide, which are sulfhydryl group blockers. This high molecular weight renin was converted into regular size renin by acidification and trypsin treatment. In contrast, the molecular weight of renin in the granules was 40000, regardless of the absence or presence of sulfhydryl group blockers. Furthermore, neither change in molecular weight nor change in activity was observed after acidification. These results indicate that regular size renin is stored in the granules and may be converted into high molecular weight renin when it is released from the granules and reacts with some substance in the cytosol fraction of renal cortical tissue.