Increased renin concentration in plasma and amniotic fluid during storage.

Area of Science:

• Biochemistry
• Physiology
• Clinical Chemistry

Background:

• Renin is a critical enzyme in the renin-angiotensin-aldosterone system, regulating blood pressure.
• Accurate renin concentration measurement is vital for diagnosing and managing various medical conditions.
• Understanding sample storage effects on renin is crucial for reliable laboratory results.

Purpose of the Study:

• To investigate the impact of different storage temperatures (5°C and -18°C) on renin concentration in human plasma and amniotic fluid.
• To determine the optimal storage conditions for preserving renin integrity.
• To explore potential mechanisms behind observed changes in renin concentration during storage.

Main Methods:

• Plasma and amniotic fluid samples were collected.
• Samples were stored at 5°C for up to 48 hours.
• Samples were stored at -18°C for up to 48 hours.
• Renin concentration was measured immediately after collection and after each storage condition.

Main Results:

• Renin concentration significantly increased in plasma (p<0.05) and amniotic fluid (P<0.02) after storage at 5°C for 48 hours.
• No significant alteration in renin concentration was observed after storage at -18°C for 48 hours.
• The increase in renin at 5°C suggests partial activation of inactive renin.

Conclusions:

• Storage of plasma and amniotic fluid at 5°C can lead to an artefactual increase in renin concentration.
• Freezing samples at -18°C is a reliable method for maintaining renin concentration.
• The findings highlight the importance of appropriate sample handling and storage protocols in renin assays.