Studies on membrane-bound renin in the mouse and rat.

Membrane-bound renin was isolated from the submaxillary gland and kidney of the white Swiss Webster mouse and from the kidney of the rat. Administration of the male sex hormone testosterone or an anabolic steroid, such as nandrolone phenpropionate (Durabolin), induces renin activity in microsomal fraction of the submaxillary gland of the young female mouse. Actinomycin D blocks this induction partially. Renin that sedimented with the microsomal fraction was isolated from the homogenized kidney of the mouse by density gradient centrifugation. Microsomal renin was also isolated from rat kidney disrupted by the N2 cavitation technique. The enzyme in the microsomal fraction that had been washed extensively was only partially active, but freezing and thawing or Triton X-100 activated microsomal renin. The same microsomal fraction contained active kallikrein. In pilot studies a plasma membrane-enriched fraction was isolated from the microsomal fraction of the homogenized rat kidney cortex that had both renin and kallikrein activity.