What is the Origin of Pregnenolone and DHEA?

These molecules derive their origin from the initial enzymatic cleavage of the cholesterol side chain, placing them at the apex of the steroid hormone biosynthetic tree. Their historical identification was crucial for mapping the entire cascade of steroid hormone production. They are the common starting point for many vital regulatory molecules.

What is the Mechanism of Pregnenolone and DHEA?

Pregnenolone is metabolized downstream into progesterone, or it can be converted to 17-OH pregnenolone to proceed toward cortisol and sex steroids. DHEA is primarily converted into androgens like androstenedione, which further yields testosterone and estrogen, or it can be directly involved in modulating GABAergic neurotransmission. The mechanism involves selective enzyme activity directing flux toward specific final products based on physiological need.

Pregnenolone and DHEA

Meaning

Pregnenolone and DHEA are classified as upstream neurosteroids, representing crucial, early precursors in the comprehensive steroidogenesis pathway originating from cholesterol. These compounds serve as foundational building blocks for the synthesis of all subsequent sex hormones, glucocorticoids, and mineralocorticoids in the adrenal glands and gonads. They also possess independent biological activity, particularly within the central nervous system.