Relaxin as a cardiovascular drug: a promise kept

Relaxin (RLX), formerly known for its effects on reproduction and pregnancy, has been later shown to be a pleiotropic hormone, capable of also targeting numerous non-reproductive organs of the cardiovascular, nervous, respiratory, tegumental, excretory and digestive systems. Most of these effects have been studied in animal models, but there is compelling evidence that RLX also acts in humans. In more recent years, human luteal-type (H2) RLX synthesised by recombinant DNA technology has been investigated in clinical trials, mostly oriented to assess its therapeutic potential in cardiovascular disease. This indication was based on the accumulating pre-clinical evidence that RLX possesses prominent biological effects on systemic and coronary blood vessels, cardiomyocyte growth and differentiation, and cardiac/vascular connective tissue remodelling. This mini-review was intended as an update of our previous article that appeared in this journal in 2009, as the last 2 years have been characterised by fundamental achievements on the clinical profile of RLX. Eventually, after many years of inconclusive studies, RLX appears to be about to reach a recognised dignity as a cardiovascular drug.