Locally produced relaxin may affect testis and vas deferens function in rats

Area of Science:

• Reproductive Biology
• Endocrinology
• Molecular Biology

Background:

• The rat testis and vas deferens express high levels of the relaxin receptor, RXFP1.
• Previous research established RXFP1 presence, necessitating investigation into relaxin's role in these tissues.

Purpose of the Study:

• To determine relaxin expression in the rat testis and vas deferens.
• To investigate the effects of exogenous relaxin on Sertoli cell proliferation and vas deferens gene expression.

Main Methods:

• Quantification of relaxin and RXFP1 mRNA levels via RT-PCR.
• Immunohistochemical detection of relaxin.
• Assessment of Sertoli cell proliferation using (3)H-thymidine incorporation.
• Analysis of vas deferens gene expression changes following relaxin treatment.

Main Results:

• Relaxin mRNA levels were lower in testis and vas deferens compared to prostate, with Sertoli cells identified as a key source in the testis.
• Relaxin immunoreactivity was observed in the seminiferous epithelium and vas deferens apical cells.
• Castration significantly reduced relaxin mRNA in the prostate and vas deferens, an effect reversed by testosterone.
• Exogenous relaxin stimulated Sertoli cell proliferation and increased mRNA levels for cystic fibrosis transmembrane regulator, inducible nitric oxide synthase, and metalloproteinase 7 in the vas deferens.

Conclusions:

• Locally produced relaxin acts as an autocrine or paracrine factor in the testis and vas deferens.
• Relaxin signaling is implicated in regulating spermatogenesis and seminal fluid composition.
• Relaxin influences Sertoli cell function and modulates genes involved in epithelial secretion and tissue reorganization within the reproductive tract.