What is the Origin of Bioactive Hormone Fraction Measurement?

The concept originates from the understanding of hormone transport and binding kinetics within human plasma, recognizing that steroid and thyroid hormones circulate primarily bound to proteins like sex hormone-binding globulin (SHBG) and albumin. The term became necessary in clinical practice to distinguish the truly accessible hormone pool. It reflects an evolution in laboratory medicine toward functionally relevant physiological metrics.

What is the Mechanism of Bioactive Hormone Fraction Measurement?

The measurement relies on various laboratory methodologies, such as equilibrium dialysis or ultrafiltration, to physically separate the unbound or "free" hormone fraction from the protein-bound fraction in a serum or plasma sample. Once separated, the concentration of the free hormone is quantified using highly sensitive assays like mass spectrometry or radioimmunoassay. This provides the clinician with the precise level of hormone available to exert its physiological effects.

Bioactive Hormone Fraction Measurement ∞ Area

Bioactive Hormone Fraction Measurement

Meaning

This is a diagnostic technique used in endocrinology to quantify the fraction of a hormone that is unbound to carrier proteins and therefore biologically active at the target tissue receptors. It provides a more accurate representation of the hormone’s functional status compared to measuring total hormone levels, which include both bound and unbound portions. This assessment is critical for clinical decision-making, particularly when evaluating symptoms that correlate poorly with total hormone concentrations.