Membrane receptors are often modulated by steroids and it is necessary to distinguish the
effects of steroids at these receptors from effects occurring at nuclear receptors. Additionally,
it may also be mechanistically important to distinguish between direct effects caused by
binding of steroids to membrane receptors and indirect effects on membrane receptor
function caused by steroid perturbation of the membrane containing the receptor. In this
regard, ent-steroids, the mirror images of naturally occurring steroids, are novel tools for …