19-Nortestosterone in mouse kidney

19-Nortestosterone was identified as a product of testosterone conversion in vitro in male mouse kidney. After incubation of [14C]testosterone with kidney slices of castrated male mice, 64% of the radioactivity was recovered as testosterone, about 6% as epitestosterone and 2.5% was identified as 19-nortestosterone. The renotrophic effect of 19-nortestosterone was at least as high as that of testosterone. Possible role of 19-nortestosterone in mouse kidney is discussed.