Sizonenko P C
Department of Pediatrics and Genetics, University of Geneva Medical School, University Canton Hospital, Switzerland.
J Endocrinol Invest. 1989;12(8 Suppl 3):59-63.
Adolescence represents the period of important somatic changes which lead to sexual maturation, pubertal growth and active functions of reproduction. Mean ages of onset of puberty are 10.9 and 11.2 in girls and boys respectively. Menarche occurs at a mean age of 13.4 yr and may be related to a critical weight. In boys, testicular growth above 4 cm2 or 4 ml is the first clinical sign of gonadal pubertal maturation. In girls, the first sign is the budding of the breast. At onset of puberty, the hypothalamus after a "quiescent" period resumes a marked pulsatile secretion of gonadotrophin-releasing hormone, leading to an increased secretion of pituitary gonadotropins which in turn stimulate the gonadal functions, i.e. the secretion of testosterone or estradiol and maturation of the spermatogenesis or the ovarian follicle. Neuroendocrine factors which probably control the onset of puberty are numerous: cerebral adrenergic and/or dopamine neurotransmitters, endogenous opioids, melatonin from the pineal gland. Gonadal maturation (gonadarche) is preceded in the infant by a post-natal surge of luteinizing hormone and at age 7 to 8 yr by an adrenal maturation (adrenarche).
青春期是身体发生重要变化的时期，这些变化会导致性成熟、青春期生长以及生殖功能活跃。女孩和男孩青春期开始的平均年龄分别为10.9岁和11.2岁。月经初潮的平均年龄为13.4岁，可能与临界体重有关。在男孩中，睾丸面积超过4平方厘米或体积超过4毫升是性腺青春期成熟的首个临床体征。在女孩中，首个体征是乳房初现。在青春期开始时，下丘脑在经历一段“静止”期后恢复显著的促性腺激素释放激素脉冲式分泌，导致垂体促性腺激素分泌增加，进而刺激性腺功能，即睾酮或雌二醇的分泌以及精子发生或卵泡的成熟。可能控制青春期开始的神经内分泌因素众多：大脑中的肾上腺素能和/或多巴胺神经递质、内源性阿片类物质、松果体分泌的褪黑素。在婴儿期，性腺成熟（性腺初现）之前会出现促黄体生成素的产后激增，在7至8岁时会出现肾上腺成熟（肾上腺初现）。
