SC 23992: radioreceptor assays for therapeutic and side effects

1. A new spirolactone (SC 23992) has been assayed in vitro to determine its affinity for mineralocorticoid and androgen receptors. 2. Although two to eight times as potent as anti-aldosterone agent as Aldactone in vivo, SC 23992 has only approximately 10% the potency in vitro. 3. This discrepancy between potency in vivo and in vitro appears to be explained on radioreceptor assay of the principal metabolites of Aldactone SC 23992. 4. SC 23992 may represent an antimineralocorticoid with less antiandrogen side effects.