An evaluation of hormonal changes at puberty in man
1Department of Growth and Development, Institute of Child Health, London.
The Journal of Endocrinology
|February 1, 1988
Summary
Puberty onset and maintenance depend on pulsatile hormone secretion, particularly during the night. Hormone levels measured during the day may not accurately reflect these crucial endocrine events.
Area of Science:
- Endocrinology
- Reproductive Biology
- Pediatric Endocrinology
Background:
- Pulsatile secretion of gonadotrophins, sex steroids, and growth hormone is vital for sexual maturation.
- Nocturnal hormonal patterns are closely linked to pubertal development and adult gonadal function.
Purpose of the Study:
- To highlight the significance of nocturnal hormone secretion in sexual maturation.
- To explain sex-specific differences in the timing of pubertal development and growth spurts.
Main Methods:
- Analysis of pulsatile hormone secretion patterns.
- Correlation of nocturnal endocrine events with pubertal onset and progression.
Main Results:
- Hormone measurements during daytime are less informative than night-time measurements for assessing sexual maturation.
- The preovulatory LH surge initiates in the early morning hours, indicating continued nocturnal influence in adults.
- Girls exhibit greater sensitivity to GnRH variations, contributing to earlier pubertal signs.
- Estradiol enhances growth hormone secretion at lower levels than testosterone, explaining sex differences in pubertal growth spurts.
Conclusions:
- Nocturnal endocrine rhythms are critical for both the initiation and maintenance of sexual maturation.
- Understanding these diurnal variations is essential for accurate assessment of pubertal development and growth.
- Sex-specific hormonal sensitivities contribute to observed differences in the timing of puberty and growth spurts.
Related Concept Videos
01:40Hormonal Regulation
Hormones regulate a significant portion of digestion through activation of the neuroendocrine system. The neuroendocrine system of digestion contains many different hormones all with multiple functions that are both, directly and indirectly, involved in digestion.
01:22Hormonal Regulation of the Menstrual Cycle
The ovarian cycle regulates endometrial changes throughout a single menstrual cycle via the coordinated action of gonadotrophin-releasing hormone (GnRH) and gonadotrophins.
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
01:26Testosterone: Functions and Regulation
The intricate hormonal interplay essential for male reproductive health begins with the release of gonadotropin-releasing hormone (GnRH) by the hypothalamus. This hormone prompts the pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). LH targets the Leydig cells in the testes, stimulating them to produce and release testosterone. In concert with testosterone, FSH acts on the Sertoli cells within the seminiferous tubules to facilitate the release of...
01:30Hormonal Control of the Ovarian Cycle
The ovarian cycle is meticulously regulated by the hypothalamic-pituitary-gonadal axis. This cycle orchestrates the release of a mature oocyte, essential for reproduction.
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
01:27Signs of Puberty
Puberty is a critical phase, typically beginning between the ages of 8 and 13 in girls and 9 and 14 in boys, though timing can vary based on genetics, environmental factors, and overall health. This period is characterized by the development of secondary sexual characteristics and the attainment of reproductive potential. Endocrine changes underpin puberty, with hormonal surges of Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) instigated by Gonadotropin-Releasing Hormone (GnRH)...
01:28Menopause
Menopause, a natural biological process marking the end of a woman's fertility, typically occurs between the fifth and sixth decade of life. This phase is characterized by the exhaustion of the ovarian follicle pool, leading to less responsive ovaries despite the high levels of Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH). The consequential decrease in estrogen production results in symptoms like hot flashes, heavy sweating, headaches, hair loss, muscle pains, vaginal...