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How Does HPG Axis Function?
Question: Hi, i have posted many times regarding hpg axis in childhood. I would like to have a good convincing answer.
I know the HPG axis queiscient in childhood (way before puberty) but is it still functioning? Ie are all hormones being secreted but in ver very low levels? Thanks
I know the HPG axis queiscient in childhood (way before puberty) but is it still functioning? Ie are all hormones being secreted but in ver very low levels? Thanks
Brief Answer:
Quiescent but functioning.
Detailed Answer:
Hello,
Welcome to HCM and thank you for this interesting query.
The activation and deactivation of the HPG axis regulate the hormonal cycles.
You are absolutely right that the axis remains quiescent through childhood, and the FSH and LH levels are low but not absent. During puberty the HPG axis is activated by the secretions of estrogen from the ovaries or testosterone from the testes. This activation of estrogen and testosterone causes physiological and psychological changes. Once activated, the HPG axis continues to function in men for the rest of their life but becomes deregulated in women, leading to menopause.
Dr. Noble Zachariah
Quiescent but functioning.
Detailed Answer:
Hello,
Welcome to HCM and thank you for this interesting query.
The activation and deactivation of the HPG axis regulate the hormonal cycles.
You are absolutely right that the axis remains quiescent through childhood, and the FSH and LH levels are low but not absent. During puberty the HPG axis is activated by the secretions of estrogen from the ovaries or testosterone from the testes. This activation of estrogen and testosterone causes physiological and psychological changes. Once activated, the HPG axis continues to function in men for the rest of their life but becomes deregulated in women, leading to menopause.
Dr. Noble Zachariah
Above answer was peer-reviewed by :
Dr. Ashwin Bhandari
Dear Dr. XXXXXXX
Many thanks for your answer. In normal healthy children, is there any reason for the FSH and LH to become absent?
I read somewhere that in young childhood, the hypothalamus and the pituitary are extra extra sensitive to testosterone, which means there must still be hpg axis functionality - but at very low levels....can you confirm this as it would make me very happy. THanks and best wishses
Many thanks for your answer. In normal healthy children, is there any reason for the FSH and LH to become absent?
I read somewhere that in young childhood, the hypothalamus and the pituitary are extra extra sensitive to testosterone, which means there must still be hpg axis functionality - but at very low levels....can you confirm this as it would make me very happy. THanks and best wishses
Brief Answer:
You are welcome. HPG axis and beyond
Detailed Answer:
Dear XXXX
You are welcome.
Gonadotropin-releasing hormone (GnRH) is secreted from the hypothalamus by GnRH-expressing neurons. The anterior portion of the pituitary gland produces luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and the gonads produce estrogen and testosterone.
Before puberty the GnRH secretion from the hypothalamus is low and hence the FSH and LH are low but not totally absent. Estrogen forms a negative feedback loop by inhibiting the production of GnRH in the hypothalamus. Part of testosterone is converted into estradiol by aromatase (CYP19A1) an enzyme expressed in the brain, liver, and adipose tissues. So if a male child is administered testosterone it is possible to have an effect on the HPG through this negative feed back.
Recent research has shown that a neurosteroid axis exists, which helps the brain cortex to regulate the hypothalamus’s production of GnRH. In addition, leptin and insulin have stimulatory effects and ghrelin has inhibitory effects on gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus.
So HPG is only a part of the hormonal orchestra controlled by factors that are being discovered.
If you have further query, you are welcome
Best wishes and regards,
Dr Noble Zachariah
You are welcome. HPG axis and beyond
Detailed Answer:
Dear XXXX
You are welcome.
Gonadotropin-releasing hormone (GnRH) is secreted from the hypothalamus by GnRH-expressing neurons. The anterior portion of the pituitary gland produces luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and the gonads produce estrogen and testosterone.
Before puberty the GnRH secretion from the hypothalamus is low and hence the FSH and LH are low but not totally absent. Estrogen forms a negative feedback loop by inhibiting the production of GnRH in the hypothalamus. Part of testosterone is converted into estradiol by aromatase (CYP19A1) an enzyme expressed in the brain, liver, and adipose tissues. So if a male child is administered testosterone it is possible to have an effect on the HPG through this negative feed back.
Recent research has shown that a neurosteroid axis exists, which helps the brain cortex to regulate the hypothalamus’s production of GnRH. In addition, leptin and insulin have stimulatory effects and ghrelin has inhibitory effects on gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus.
So HPG is only a part of the hormonal orchestra controlled by factors that are being discovered.
If you have further query, you are welcome
Best wishes and regards,
Dr Noble Zachariah
Note: For more information on hormonal imbalance symptoms or unmanaged diabetes with other comorbid conditions, get back to us & Consult with an Endocrinologist. Click here to book an appointment.
Above answer was peer-reviewed by :
Dr. Ashwin Bhandari
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