Relaxin bioactivity and immunoactivity in human corpora lutea

Area of Science:

• Reproductive biology
• Endocrinology
• Hormone research

Background:

• Corpora lutea (CL) are crucial endocrine structures in the female reproductive cycle.
• Relaxin is a hormone implicated in pregnancy and reproductive processes.
• Quantifying relaxin activity in CL is important for understanding reproductive physiology.

Purpose of the Study:

• To determine and compare relaxin-like activity in corpora lutea (CL) from pregnant and non-pregnant women.
• To correlate immunoactivity with bioactivity of relaxin in CL extracts.

Main Methods:

• Extraction of relaxin-like substances from corpora lutea (CL) of pregnant and non-pregnant women.
• Quantification using radioimmunoassay (RIA) for immunoactivity.
• Assessment using guinea pig pubic symphysis palpation assay for biological activity.

Main Results:

• Relaxin-like activity, measured by both radioimmunoassay and bioassay, was significantly higher in CL from pregnant women.
• The biological activity of CL extracts from pregnant women closely paralleled their immunoactivity.
• Relaxin content in CL from non-pregnant women was below the detection limit of the bioassay.

Conclusions:

• Corpora lutea (CL) of pregnancy exhibit substantial relaxin-like activity.
• Immunoassays and bioassays provide consistent measures of relaxin activity in CL.
• Relaxin plays a significant role in the corpora lutea during human pregnancy.