[Lipotropins (beta- and gamma-LPH). Valid indicators of corticotropic function]

Area of Science:

• Endocrinology
• Biochemistry

Background:

• Adrenocorticotropic hormone (ACTH) and lipotropic hormone (LPH) share a common precursor.
• Assessing corticotropic function relies on measuring these hormones.

Purpose of the Study:

• To evaluate LPH as a superior marker for corticotropic function compared to ACTH.
• To investigate the stability and diagnostic utility of LPH plasma levels.

Main Methods:

• Simultaneous measurement of plasma ACTH and LPH levels in control subjects and patients.
• Assessment under basal conditions and after dynamic corticotropic axis stimulation.
• Evaluation of LPH stability in blood ex vivo and its renal clearance.

Main Results:

• Established normal basal plasma levels for ACTH and LPH, confirming parallel secretion.
• Demonstrated LPH stability in blood at room temperature, unlike ACTH.
• Identified the kidney as the primary site of LPH catabolism.
• Showcased the diagnostic value of LPH in primary adrenal insufficiency and corticotropic deficiency.

Conclusions:

• Plasma LPH levels provide a reliable index of corticotropic function, except in specific dissociation scenarios.
• LPH determination offers advantages over ACTH measurement due to its stability and diagnostic utility.