Advances in basic biological research have proceeded rapidly in recent
years. The fields of molecular genetics and immunology have experienced
dramatic breakthroughs, capturing the imagination of both the scientific
community and the general public. With less public notice, receptor
biology has brought a cascade of new discoveries and insights. The
entire science of pharmacology has been virtually rewritten in terms of
receptor phenomenology. In particular, the discovery of specific
receptors for steroid and protein hormones has been of seminal
importance. With this new information, we have advanced our
understanding of the mechanism and specifity of hormone action. We can
now explain how hormones interact selectively with specific target cells
and how hormones alter biochemical events within the target cells. These
facts have already impacted on applied problems of clinical medicine,
particularly in diagnosis and treatment of cancer and some metabolic
diseases. Now, a new and important application of basic receptor biology
and chemistry looms ahead. Within a few short years since the discovery
of the progesterone receptor, chemists have synthesized molecules with a
greater affinity for the receptor than progesterone itself and which,
while occupying the receptor, fail to trigger the events which transform
a target cell from the unstimulated to the stimulated state. This is the
basis of the competitive inhibitory action of the anti-progestational
agent, synthesized by the chemists at Roussel Uc1af, Paris, and
designated RU 486.