Sign-in to Ask A Doctor - 24x7
OR
Sign in with Google
How Does LH And FSH Dymaics Work?
Question: Hi, I want to ask about fsh and lh dynamics, I know it's present throughout life right from beginning in varied quantity....and is suppressed in childood. But does it ever reach zero during childhood ?
Or does the system always work actively , but at a very low level?
Or does the system always work actively , but at a very low level?
Brief Answer:
Hello
Detailed Answer:
Hello XXXX
Good day and welcome to healtcare magic.
Gonadotropic releasing hormone (GnRH) is produced in hypothalamus and that determines the production of LH and FSH in pituitary.
LH and FSH surge occurs a month after birth and lasts up to 6-12 months after birth. After that period, GnRH neurons are somewhat silent until puberty. A particular frequency of firing from GnRH neurons are required for the LH and FSH production. LH requires high frequency Gnrh firing(pulsatality) and FSH require a low frequency GnRH firing.
Hence the GnRH frequency and intensity largely decide LH and FSH production. In childhood it never reach zero, but the firing levels are so low and that wouldnt make any significant change in sex hormones. During puberty, the GnRH start firing again during night first.
Occasionally, for varioud reasons, abnormal GnRH firing occurs in childhood and that cause premature ( prcociuos) puberty. I encourage you to go through the reproductive system physiology in www.endotext.org . This website is primarily for doctors, but may be able to get an overall idea. Please feel free to ask if you need more clarifications.
Regards XXXXXXX
Hello
Detailed Answer:
Hello XXXX
Good day and welcome to healtcare magic.
Gonadotropic releasing hormone (GnRH) is produced in hypothalamus and that determines the production of LH and FSH in pituitary.
LH and FSH surge occurs a month after birth and lasts up to 6-12 months after birth. After that period, GnRH neurons are somewhat silent until puberty. A particular frequency of firing from GnRH neurons are required for the LH and FSH production. LH requires high frequency Gnrh firing(pulsatality) and FSH require a low frequency GnRH firing.
Hence the GnRH frequency and intensity largely decide LH and FSH production. In childhood it never reach zero, but the firing levels are so low and that wouldnt make any significant change in sex hormones. During puberty, the GnRH start firing again during night first.
Occasionally, for varioud reasons, abnormal GnRH firing occurs in childhood and that cause premature ( prcociuos) puberty. I encourage you to go through the reproductive system physiology in www.endotext.org . This website is primarily for doctors, but may be able to get an overall idea. Please feel free to ask if you need more clarifications.
Regards XXXXXXX
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Dear Dr XXXXXXX
Thank you for your welcome and for valued answer.
Suppose puberty hasnt been reached yet , and the child subsequently has some anabolic steroid treatment for short time.
Can this treatment cause the GnRH to start firing again and advance puberty? Or will there ALWAYS be a negative feedback mechanism?
Thanks and Best Regards
Thank you for your welcome and for valued answer.
Suppose puberty hasnt been reached yet , and the child subsequently has some anabolic steroid treatment for short time.
Can this treatment cause the GnRH to start firing again and advance puberty? Or will there ALWAYS be a negative feedback mechanism?
Thanks and Best Regards
Brief Answer:
Hi
Detailed Answer:
Hello,
Yes, if puberty is delayed for some reason ( commonest being constitutional delay of puberty or CDP) , endocrinologists prime the hypothalamus by giving a short course of steroid hormone ( either testosterone or oxandrolone). This is usually 3 doses, which can kick start the GnRH firing and hence puberty. Once started, usually it will not stop naturally until old age or unless there is an injury to pituitary or hypothalamus.
The negative feedback mechanism come from testosterone and other male hormones. Usually the negative feedback system keep hormones in normal , healthy quantity. If testes start producing excessive testosterone, then the negative feedback system suppress GnRH /LH/FSH.
On the contrary, if the testes produces less testosterone, LH and GnRH levels go up. If testes has trouble with sperm production, FSH and GnRH goes high. LH is primarily for testosterone production and FSH is for sperm production.
However, if you use synthetic steroids or androgens for prolonged period ( like in body building), the GnRH/LH/FSH get suppressed for a long time and it may be months before they can start functioning again after stopping these medications.
Regards
Binu
Hi
Detailed Answer:
Hello,
Yes, if puberty is delayed for some reason ( commonest being constitutional delay of puberty or CDP) , endocrinologists prime the hypothalamus by giving a short course of steroid hormone ( either testosterone or oxandrolone). This is usually 3 doses, which can kick start the GnRH firing and hence puberty. Once started, usually it will not stop naturally until old age or unless there is an injury to pituitary or hypothalamus.
The negative feedback mechanism come from testosterone and other male hormones. Usually the negative feedback system keep hormones in normal , healthy quantity. If testes start producing excessive testosterone, then the negative feedback system suppress GnRH /LH/FSH.
On the contrary, if the testes produces less testosterone, LH and GnRH levels go up. If testes has trouble with sperm production, FSH and GnRH goes high. LH is primarily for testosterone production and FSH is for sperm production.
However, if you use synthetic steroids or androgens for prolonged period ( like in body building), the GnRH/LH/FSH get suppressed for a long time and it may be months before they can start functioning again after stopping these medications.
Regards
Binu
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Thanks Dr XXXXXXX
And does this priming take place in CDP subjects even if they didnt have treatment (through natural endogonous steroids) ? And if yes, does this apply in the earlier 'mini-puberty' when we were baby?
Secondly many studies online, on CDP being treated with 3 months oxandrolone, show a decrease in LH at 3 months...this doesnt indicate 'priming' but actually indicates the opposite ie suppression.
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2265.1993.tb00520.x/abstract
Kindly could you clarify for my understand?
Best Regards
XXXX
And does this priming take place in CDP subjects even if they didnt have treatment (through natural endogonous steroids) ? And if yes, does this apply in the earlier 'mini-puberty' when we were baby?
Secondly many studies online, on CDP being treated with 3 months oxandrolone, show a decrease in LH at 3 months...this doesnt indicate 'priming' but actually indicates the opposite ie suppression.
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2265.1993.tb00520.x/abstract
Kindly could you clarify for my understand?
Best Regards
XXXX
Brief Answer:
Hello
Detailed Answer:
Hello,
Spontanous puberty occur in CDP patients later as there are no structural abnormalities. ( the system is just lazy ). Eventually they end up having normal puberty, but at a later age. However, as puberty has a great impact in the skeletal growth and height, waiting for too long for natural puberty to occur may not be always feasible in these group of patients. Besides, some of these kids develop psychological problems when their peers develop body hair and start growing tall. That is one rationale behind priming with Oxandrolone/testosterone.
So in short even if you dont opt to treat them with short course oxandrolone, these CDP patients enter puberty later. .
If you read that article carefully, it mentions that eventhough there was a temporary supression in LH production, as soon as it is weaned off, there was a rebound rise in LH levels. What you have to understand is that, androgen dose used in treatment is much higher than physiological levels. The priming occurs at hypothalamus level. LH drops just temporarily.
In the XXXXXXX puberty too, there is a suppression of baby's GnRH/LH axis ( negative feedback) due maternal hormones and when the baby is born, this negative feed back is gone and there is a sudden GnRH neuron activation and firing start around a month later after birth.
Regards
Binu
Hello
Detailed Answer:
Hello,
Spontanous puberty occur in CDP patients later as there are no structural abnormalities. ( the system is just lazy ). Eventually they end up having normal puberty, but at a later age. However, as puberty has a great impact in the skeletal growth and height, waiting for too long for natural puberty to occur may not be always feasible in these group of patients. Besides, some of these kids develop psychological problems when their peers develop body hair and start growing tall. That is one rationale behind priming with Oxandrolone/testosterone.
So in short even if you dont opt to treat them with short course oxandrolone, these CDP patients enter puberty later. .
If you read that article carefully, it mentions that eventhough there was a temporary supression in LH production, as soon as it is weaned off, there was a rebound rise in LH levels. What you have to understand is that, androgen dose used in treatment is much higher than physiological levels. The priming occurs at hypothalamus level. LH drops just temporarily.
In the XXXXXXX puberty too, there is a suppression of baby's GnRH/LH axis ( negative feedback) due maternal hormones and when the baby is born, this negative feed back is gone and there is a sudden GnRH neuron activation and firing start around a month later after birth.
Regards
Binu
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Thanks again Dr XXXXXXX
So in the baby, are androgens responsible for step by step priming of his hypothalamus , leading to XXXXXXX puberty?
What I cannot understand is hypothalamic neurons control androgens...yet for the phenomenon of priming , androgens are controlling hypothalamic neurons!
This means adrenal androgens also contribute to priming.
And i feel sorry for CDP boys who had hormone priming, as this means for the rest of their life they cannot escape fact their GnRH/LH axis was started by artificial means and stays that way
So in the baby, are androgens responsible for step by step priming of his hypothalamus , leading to XXXXXXX puberty?
What I cannot understand is hypothalamic neurons control androgens...yet for the phenomenon of priming , androgens are controlling hypothalamic neurons!
This means adrenal androgens also contribute to priming.
And i feel sorry for CDP boys who had hormone priming, as this means for the rest of their life they cannot escape fact their GnRH/LH axis was started by artificial means and stays that way
Brief Answer:
hi
Detailed Answer:
Hello,
good evening.
Release of GnRH neuron inhibition from maternal hormones at birth leads to minipuberty. During this stage, babies often have adult range LH/FSH and Testostreone levels.
Then, it goes to juvenile phase ( due to a complex inhibitory mechanisms by body) where very low levels of LH and FSH are produced. At puberty, first thing to occur is adrenarche, where adrenal androgen production start. During this time, the intrinsic inhibitory mechanisms by the body eases and puberty starts.
It is proven that, CDP boys will enter in to puberty by a short course of androgen treatment, however, the exact mechanism behind this is not clear.
CDP boys whose puberty was started by external androgen treatment will have no effect on their GnRH/LH axis in the future
( however, few boys may have other diseases like hypogonadotropic hypogonadism which was mistaken for CDP may continue to have problems. In this group, they need ongoing androgen treatment in the future too, with up to 30% boys improving spontaneously).
Oh god, this is a highly complex but very interesting subject. Body's mechanisms of initiating and maintaining puberty is fantastic, but not fully understood. This reminds us that GOD is great and he has done so much of programing in our body.
Regards
Binu
hi
Detailed Answer:
Hello,
good evening.
Release of GnRH neuron inhibition from maternal hormones at birth leads to minipuberty. During this stage, babies often have adult range LH/FSH and Testostreone levels.
Then, it goes to juvenile phase ( due to a complex inhibitory mechanisms by body) where very low levels of LH and FSH are produced. At puberty, first thing to occur is adrenarche, where adrenal androgen production start. During this time, the intrinsic inhibitory mechanisms by the body eases and puberty starts.
It is proven that, CDP boys will enter in to puberty by a short course of androgen treatment, however, the exact mechanism behind this is not clear.
CDP boys whose puberty was started by external androgen treatment will have no effect on their GnRH/LH axis in the future
( however, few boys may have other diseases like hypogonadotropic hypogonadism which was mistaken for CDP may continue to have problems. In this group, they need ongoing androgen treatment in the future too, with up to 30% boys improving spontaneously).
Oh god, this is a highly complex but very interesting subject. Body's mechanisms of initiating and maintaining puberty is fantastic, but not fully understood. This reminds us that GOD is great and he has done so much of programing in our body.
Regards
Binu
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Dear Dr XXXXXXX Thank you for all your support and valued advice so far.
i know this is a complex subject, but can we say the ever increasing androgens after birth led to 'progress of XXXXXXX puberty?
If androgens can cause teenagers to enter puberty , then its possible androgens can also cause babies to enter XXXXXXX puberty?
Your clarification would be appreciated.
Thanks and Best Regards
i know this is a complex subject, but can we say the ever increasing androgens after birth led to 'progress of XXXXXXX puberty?
If androgens can cause teenagers to enter puberty , then its possible androgens can also cause babies to enter XXXXXXX puberty?
Your clarification would be appreciated.
Thanks and Best Regards
Brief Answer:
Androgens cause XXXXXXX puberty and puberty
Detailed Answer:
Hello,
Good day.
After birth, maternal hormone influence ( negative feedback) on GnRH is absent and it starts firing, this leads to increase in LH and FSH and ultimately androgens. you are right, androgen surge in a male baby cause XXXXXXX puberty. in girls, increase in estrogen cause XXXXXXX puberty
Regards
Binu
Androgens cause XXXXXXX puberty and puberty
Detailed Answer:
Hello,
Good day.
After birth, maternal hormone influence ( negative feedback) on GnRH is absent and it starts firing, this leads to increase in LH and FSH and ultimately androgens. you are right, androgen surge in a male baby cause XXXXXXX puberty. in girls, increase in estrogen cause XXXXXXX puberty
Regards
Binu
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Dear Dr XXXXXXX what I meant is do androgens prime the hypothalamus in babies and leading to the XXXXXXX puberty? (in the same way androgens prime leads to second puberty)
Finally what is pulse interval of Gnrh in boys and adult males?
Thanks Dr XXXXXXX wishing you all the best
Regards
XXXX
Finally what is pulse interval of Gnrh in boys and adult males?
Thanks Dr XXXXXXX wishing you all the best
Regards
XXXX
Brief Answer:
Hello
Detailed Answer:
Minipuberty is not initiated by androgens.
Release of GnRH neuron inhibition from maternal hormones at birth leads to minipuberty.
Later in life, adrenal androgens may play a role in initiation of puberty, however there are several other factors which orchestrates onset of puberty and many of those are incompletely understood.
In boys with lazy GnRH neurons ( like in CDP), there is a PUSH effect ( like an ignition) when we start a small dose of external androgen briefly. This will kick start puberty after few weeks/months ( there is an initial LH suppression and later a rebound activation).
Regards
B
Hello
Detailed Answer:
Minipuberty is not initiated by androgens.
Release of GnRH neuron inhibition from maternal hormones at birth leads to minipuberty.
Later in life, adrenal androgens may play a role in initiation of puberty, however there are several other factors which orchestrates onset of puberty and many of those are incompletely understood.
In boys with lazy GnRH neurons ( like in CDP), there is a PUSH effect ( like an ignition) when we start a small dose of external androgen briefly. This will kick start puberty after few weeks/months ( there is an initial LH suppression and later a rebound activation).
Regards
B
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Thank you dr XXXXXXX
Just one more thing, what is the Gnrh pulse frequency in boys , I read somewhere every two hours then elsewhere every 30-60minutes ? And is frequency similar pattern in adult males?
Thanks for everything. Wishing u all the best
Just one more thing, what is the Gnrh pulse frequency in boys , I read somewhere every two hours then elsewhere every 30-60minutes ? And is frequency similar pattern in adult males?
Thanks for everything. Wishing u all the best
Brief Answer:
Hi
Detailed Answer:
Hi,
As you said, different scientists have given different opinions regarding GnRH pulse frequency. Most widely accepted is once in 90 minutes pulsus . Again high frequency pulse favours LH generaton, low frequency pulse favours FSH generation.
I had to refer to my text books to answer your last question ( we tend to forget these things once out of training and while busy practicing) and I found out one more thing which I forgot to mention earlier. GNRH has an intrinsic capacity to self prime or self activate GnRH receptors which is another mechanism of activation in XXXXXXX puberty and puberty later.
Regards
B
Hi
Detailed Answer:
Hi,
As you said, different scientists have given different opinions regarding GnRH pulse frequency. Most widely accepted is once in 90 minutes pulsus . Again high frequency pulse favours LH generaton, low frequency pulse favours FSH generation.
I had to refer to my text books to answer your last question ( we tend to forget these things once out of training and while busy practicing) and I found out one more thing which I forgot to mention earlier. GNRH has an intrinsic capacity to self prime or self activate GnRH receptors which is another mechanism of activation in XXXXXXX puberty and puberty later.
Regards
B
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. Chakravarthy Mazumdar
Answered by
Get personalised answers from verified doctor in minutes across 80+ specialties
