Adrenarche: A stage of development at which the ADRENAL GLANDS undergo maturation leading to the capability of producing increasing amounts of adrenal androgens, DEHYDROEPIANDROSTERONE and ANDROSTENEDIONE. Adrenarche usually begins at about 7 or 8 years of age before the signs of PUBERTY and continues throughout puberty.Zona Reticularis: The inner zone of the adrenal cortex. This zone produces the enzymes that convert PREGNENOLONE, a 21-carbon steroid, to 19-carbon steroids (DEHYDROEPIANDROSTERONE; and ANDROSTENEDIONE) via 17-ALPHA-HYDROXYPREGNENOLONE.Puberty, Precocious: Development of SEXUAL MATURATION in boys and girls at a chronological age that is 2.5 standard deviations below the mean age at onset of PUBERTY in the population. This early maturation of the hypothalamic-pituitary-gonadal axis results in sexual precocity, elevated serum levels of GONADOTROPINS and GONADAL STEROID HORMONES such as ESTRADIOL and TESTOSTERONE.Progesterone Reductase: An enzyme that catalyzes the reduction of a 3 beta-hydroxy-delta(5)-steroid to 3-oxo-delta(4)-steroid in the presence of NAD. It converts pregnenolone to progesterone and dehydroepiandrosterone to androstenedione. EC 126.96.36.199.Gigantism: The condition of accelerated and excessive GROWTH in children or adolescents who are exposed to excess HUMAN GROWTH HORMONE before the closure of EPIPHYSES. It is usually caused by somatotroph hyperplasia or a GROWTH HORMONE-SECRETING PITUITARY ADENOMA. These patients are of abnormally tall stature, more than 3 standard deviations above normal mean height for age.Steroid 17-alpha-Hydroxylase: A microsomal cytochrome P450 enzyme that catalyzes the 17-alpha-hydroxylation of progesterone or pregnenolone and subsequent cleavage of the residual two carbons at C17 in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP17 gene, generates precursors for glucocorticoid, androgen, and estrogen synthesis. Defects in CYP17 gene cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL) and abnormal sexual differentiation.Dehydroepiandrosterone Sulfate: The circulating form of a major C19 steroid produced primarily by the ADRENAL CORTEX. DHEA sulfate serves as a precursor for TESTOSTERONE; ANDROSTENEDIONE; ESTRADIOL; and ESTRONE.Etiocholanolone: The 5-beta-reduced isomer of ANDROSTERONE. Etiocholanolone is a major metabolite of TESTOSTERONE and ANDROSTENEDIONE in many mammalian species including humans. It is excreted in the URINE.Adrenal Cortex: The outer layer of the adrenal gland. It is derived from MESODERM and comprised of three zones (outer ZONA GLOMERULOSA, middle ZONA FASCICULATA, and inner ZONA RETICULARIS) with each producing various steroids preferentially, such as ALDOSTERONE; HYDROCORTISONE; DEHYDROEPIANDROSTERONE; and ANDROSTENEDIONE. Adrenal cortex function is regulated by pituitary ADRENOCORTICOTROPIN.Steroid Metabolism, Inborn Errors: Errors in metabolic processing of STEROIDS resulting from inborn genetic mutations that are inherited or acquired in utero.Pan paniscus: The pygmy chimpanzee, a species of the genus Pan, family HOMINIDAE. Its common name is Bonobo, which was once considered a separate genus by some; others considered it a subspecies of PAN TROGLODYTES. Its range is confined to the forests of the central Zaire basin. Despite its name, it is often of equal size to P. troglodytes.Endocrinology: A subspecialty of internal medicine concerned with the metabolism, physiology, and disorders of the ENDOCRINE SYSTEM.Dehydroepiandrosterone: A major C19 steroid produced by the ADRENAL CORTEX. It is also produced in small quantities in the TESTIS and the OVARY. Dehydroepiandrosterone (DHEA) can be converted to TESTOSTERONE; ANDROSTENEDIONE; ESTRADIOL; and ESTRONE. Most of DHEA is sulfated (DEHYDROEPIANDROSTERONE SULFATE) before secretion.Adrenal Glands: A pair of glands located at the cranial pole of each of the two KIDNEYS. Each adrenal gland is composed of two distinct endocrine tissues with separate embryonic origins, the ADRENAL CORTEX producing STEROIDS and the ADRENAL MEDULLA producing NEUROTRANSMITTERS.Steroid 21-Hydroxylase: An adrenal microsomal cytochrome P450 enzyme that catalyzes the 21-hydroxylation of steroids in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP21 gene, converts progesterones to precursors of adrenal steroid hormones (CORTICOSTERONE; HYDROCORTISONE). Defects in CYP21 cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL).Cytochromes b5: Cytochromes of the b group that are found bound to cytoplasmic side of ENDOPLASMIC RETICULUM. They serve as electron carrier proteins for a variety of membrane-bound OXYGENASES. They are reduced by the enzyme CYTOCHROME-B(5) REDUCTASE.Androgens: Compounds that interact with ANDROGEN RECEPTORS in target tissues to bring about the effects similar to those of TESTOSTERONE. Depending on the target tissues, androgenic effects can be on SEX DIFFERENTIATION; male reproductive organs, SPERMATOGENESIS; secondary male SEX CHARACTERISTICS; LIBIDO; development of muscle mass, strength, and power.17-alpha-Hydroxyprogesterone: A metabolite of PROGESTERONE with a hydroxyl group at the 17-alpha position. It serves as an intermediate in the biosynthesis of HYDROCORTISONE and GONADAL STEROID HORMONES.3-Hydroxysteroid Dehydrogenases: Catalyze the oxidation of 3-hydroxysteroids to 3-ketosteroids.Puberty: A period in the human life in which the development of the hypothalamic-pituitary-gonadal system takes place and reaches full maturity. The onset of synchronized endocrine events in puberty lead to the capacity for reproduction (FERTILITY), development of secondary SEX CHARACTERISTICS, and other changes seen in ADOLESCENT DEVELOPMENT.