Ren-2 as well as Ren-1 renin exists in the kidney and plasma of a two-renin gene mouse.

Ren-1 renin is synthesized in the kidney of every mouse. Ren-2 renin has been observed in the submandibular gland (SMG) of male mice carrying two renin genes. However, it is not known if Ren-2 renin is in the kidney and blood of the two-renin gene mice. In this study, a direct ELISA for Ren-2 renin (SMG renin) was established by a sandwich method. This ELISA could measure the Ren-2 active renin in the range from 1 to 100 ng and distinguish Ren-2 active from not only Ren-1 renin but also Ren-2 prorenin. By a combination of this assay system and conventional methods, the pro-form as well as the active form of Ren-2 renin was found in the kidney and plasma of male AKR mice carrying two-renin genes.