Relaxin and relaxin receptors in brain

Abstract

Recent studies have shown that in addition to its role as a hormone of pregnancy, relaxin also has physiological functions in the central nervous system [1, 2, 3]. In the rat brain, relaxin binding sites have been located in the organum vasculosum of the lamina terminalis (OVLT) and the subfornical organ (SFO) [4] and centrally administered relaxin increases neuronal Fos expression in these areas [5]. Relaxin binding was also found in a deep layer of rat cerebral cortex [4, 6], a site which is inaccessible to circulating relaxin. However, relaxin mRNA has been detected in rat cortex [6], leading to the hypothesis that relaxin may be produced, released and act locally in this area of the brain.