What is the Origin of Intracrinological Metabolism?

The term was coined to differentiate local steroid hormone production from classical endocrinology, emphasizing the autonomous metabolic capabilities within peripheral tissues. It highlights the complexity of steroid hormone action, which extends beyond the endocrine gland output. The focus is on tissue-specific hormone synthesis.

What is the Mechanism of Intracrinological Metabolism?

Within the cell, precursor steroids, often derived from circulating Sex Hormone-Binding Globulin (SHBG)-bound fractions or adrenal output, are converted by tissue-specific enzymes like sulfatases or 5-alpha reductase. This localized synthesis allows for precise modulation of receptor occupancy precisely where the action is needed, bypassing systemic feedback loops. The local concentration dictates the ultimate physiological effect at that site.

Intracrinological Metabolism ∞ Area

Intracrinological Metabolism

Meaning

Intracrinological Metabolism describes the process where target cells locally synthesize active steroid hormones, such as androgens or estrogens, from circulating precursors rather than relying solely on direct secretion from primary endocrine glands like the adrenals or gonads. This localized production allows for paracrine or autocrine regulation independent of the systemic HPG axis control. Tissues possess the necessary enzymatic machinery for this conversion.