Tissue-specific effects of relaxin on the reproductive tract of neonatal gilts

In the pig, relaxin treatment for 2 d from birth (postnatal day 0, PND 0) was not uterotrophic, but it increased cervical size. To understand the mechanism underlying this tissue-specific response, relaxin receptor (LGR7) expression in the neonatal uterus and cervix was investigated. At PND 2, quantitative RT-PCR analysis showed that LGR7 levels were higher in the cervix than in the uterus. Interestingly, relaxin decreased cervical LGR7 expression when compared to that of the controls. Differential expression of LGR7 between uterine and cervical tissues may contribute to tissue-specific relaxin responsiveness in the neonatal porcine reproductive tract.