Isolation of Membrane-Bound Renal Enzymes that Metabolize Kinins and Angtotensins.
Technical rept. no. 1, 1 Mar 75-31 May 77,
TEXAS UNIV HEALTH SCIENCE CENTER DALLAS
Pagination or Media Count:
Cortex of rat kidney was homogenized and fractions enriched in plasma membrane, endoplasmic reticulum or brush border were prepared by several techniques of differential centrifugation. The identity and homogeneity of the membrane fragments were investigated by assaying marker enzymes and by transmission and scanning electron microscopy. Kallikrein was present in both plasma membrane and endoplasmic reticulum enriched fractions isolated by two fractionation procedures. Kallikrein was highly concentrated in plasma membrane fraction but was absent from the brush border membrane of proximal tubular cells. Cells of transplated renal tumors of the rat, originating from the proximal tubule, had no kallikrein activity. Kininase activity, angiotensin I-converting enzyme kininase II and angiotensinase were found in plasma membrane enriched fraction and especially in the fraction containing isolated brush border.
- Anatomy and Physiology