Solid-phase double-antibody radio-immunoassay for atrial natriuretic factor

Area of Science:

• Biochemistry
• Endocrinology
• Analytical Chemistry

Background:

• Atrial natriuretic factor (ANF) plays a crucial role in cardiovascular homeostasis.
• Accurate measurement of ANF in human plasma is essential for understanding various physiological and pathological conditions.

Purpose of the Study:

• To develop and validate a solid-phase radio-immunoassay (RIA) for the quantitative determination of atrial natriuretic factor (ANF) in human plasma.
• To establish the sensitivity, stability, and reliability of the developed RIA method.

Main Methods:

• Solid-phase radio-immunoassay utilizing iodinated alpha human ANF (αhANF) as a tracer.
• Iodination performed using the iodogen method, followed by purification via DEAE-Sephadex A-25 chromatography.
• Extraction of immunoreactive ANF from human plasma using Sep-Pak C18 cartridges.

Main Results:

• The developed RIA demonstrated excellent stability of the radio-iodinated tracer, usable for up to 28 weeks with satisfactory batch-to-batch consistency.
• Extraction recovery of αhANF from whole blood was high (85 ± 12%).
• The assay sensitivity was determined to be 1.6 pg/tube, translating to 1 pg/ml of plasma. Mean plasma ANF levels in normal subjects were found to be 23 ± 12 pg/ml.

Conclusions:

• A robust and sensitive solid-phase radio-immunoassay for human plasma ANF has been successfully developed.
• The method is stable, reliable, and suitable for routine clinical and research applications requiring ANF quantification.
• The established assay allows for accurate measurement of plasma ANF, contributing to the understanding of cardiovascular regulation.