MSI_000053304

Pregnenolone is a derivative of cholesterol, the product of cytochrome P450 side-chain cleavage (EC 1.14.15.6, CYP11A1. This reaction consists of three consecutive monooxygenations, a 22-hydroxylation, a 20-hydroxylation, and the cleavage of the C20-C22 bond, yielding pregnenolone. Pregnenolone is the precursor to gonadal steroid hormones and the adrenal corticosteroids. This reaction occurs in steroid hormone-producing tissues such as the adrenal cortex, corpus luteum, and placenta. The most notable difference between the placenta and other steroidogenic tissues is that electron supply to CYP11A1 limits the rate at which cholesterol is converted into pregnenolone in the placenta. The limiting component for electron delivery to CYP11A1 is the concentration of adrenodoxin reductase in the mitochondrial matrix which is insufficient to maintain the adrenodoxin pool in a fully reduced state. Pregnenolone is also a neurosteroid, and is produced in the spinal cord; CYP11A1 is the key enzyme catalyzing the conversion of cholesterol into pregnenolone, the rate-limiting step in the biosynthesis of all classes of steroids, and has been localized in sensory networks of the spinal cord dorsal horn. In the adrenal glomerulosa cell, angiotensin II, one of the major physiological regulators of mineralocorticoid synthesis, appears to affect most of the cholesterol transfer to the mitochondrial outer membrane and many steps in the transport to the inner membrane. Thus, it exerts a powerful control over the use of cholesterol for aldosterone production (PMID: 17222962, 15823613, 16632873, 15134809). C147908 - Hormone Therapy Agent > C548 - Therapeutic Hormone > C1636 - Therapeutic Steroid Hormone D006730 - Hormones, Hormone Substitutes, and Hormone Antagonists > D006728 - Hormones COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS Pregnenolone (3β-Hydroxy-5-pregnen-20-one) is a powerful neurosteroid, the main precursor of various steroid hormones including steroid ketones. Pregnenolone acts as a signaling-specific inhibitor of cannabinoid CB1 receptor, inhibits the effects of tetrahydrocannabinol (THC) that are mediated by the CB1 receptors. Pregnenolone can protect the brain from cannabis intoxication[1][2]. Pregnenolone is also a TRPM3 channel activator, and also can weakly activate TRPM1 channels[3]. Pregnenolone (3β-Hydroxy-5-pregnen-20-one) is a powerful neurosteroid, the main precursor of various steroid hormones including steroid ketones. Pregnenolone acts as a signaling-specific inhibitor of cannabinoid CB1 receptor, inhibits the effects of tetrahydrocannabinol (THC) that are mediated by the CB1 receptors. Pregnenolone can protect the brain from cannabis intoxication[1][2]. Pregnenolone is also a TRPM3 channel activator, and also can weakly activate TRPM1 channels[3].