Research in the hormone relaxin has advanced considerably since the first international congress on this subject in Italy in 1982. Human relaxin has been synthesised and the first clinical trials performed. There is now much more information on the role of relaxin in the maintenance of pregnancy and its role at parturition as a paracrine hormone. Further, many new sites for relaxin action have now been described - these include the brain, heart, blood vessels, gastrointestinal tract, prostate and the nonpregnant ovary. Relaxin research in many species has advanced and much more is known now about the control of relaxin secretion and relaxin receptors. The proceedings of the congress chart the future for relaxin research. This volume should prove beneficial to researchers and specialists in the field.