What Is The LH And FSH Dynamics During The Pre Pubertal Stage?
I have a question regarding LH FSH dynamics during the prepubertal queiscience - are these gonadotropins physiologically STILL present during that time?
This topic is very important to me ....please advise so i can have a final answer and close the subject.
Thanks and best Regards
LH and FSH won't be physiologically present
Detailed Answer:
Hi,
Welcome to HCM. I have gone through the question and understand your concerns.
Are you a medical student / research student? Or just interested in the subject?
The doubts you have asked is genuine. But unfortunately the answers are not clear till now. I will explain whatever is known about these things till now.
The pituitary gonadotrophs are secreting LH and FSH, which in turn is under the influence of GnRH neurons, which in turn is under various modulations from other neurons - the most important being Kisspeptin neurons.
The HPG ( hypothalamic pituitary gonadal axis) is active at birth. This is called "mini puberty". This will last for 6 months to 2 yrs of age. After that pituitary won't produce these hormones till puberty.
In puberty after adrenarche small amount of estrogen will be produced in body. This estrogen will activate the Kisspeptin neurons- leading to activation of GnRH neurons and there by pituitary gonadotrophs. This will start the normal pulses of LH and FSH leading to the normal puberty - menstruation in females and sexual development in males.
The question is very scientific and so the answer is.
Hope I have answered your questions. If you have any further queries I will be happy to help you.
Regards,
Dr Ajish TP [MD,DM]
Consultant Endocrinologist
I'm interested in the subject as i underwent low dose anabolic steroid treatment (2.5mg daily oxandrolone) when i was 14.5 lasting for 3 months to boost my height.
Since then, i have discovered that steroids taken during this critical age can cause hypothalamus to mature and secrete Gnrh. I dont mind this too much, but i would mind if i had ZERO GNRH/LH/FSH and then the treatment caused first secretion of these hormones. Because that means the end product of these hormones, testosterone, is being secreted and reacted with various tissues for the FIRST TIME ie voice, bone, hair follicle etc....
Thats the reason i want to be assured that normally, just like we breathe in oxygen, routinely there is some minute LH/FSH pulses during the juvenile period.
Can you kindly advise further? Many Thanks and Best Regards
Oxandralone would have kick started your puberty
Detailed Answer:
Hi XXXX,
Welcome back.
I can understand your concerns.
You should have testosterone production in body at least by 14 years. This is essential for normal bone growth and sexual development. So as Endocrinologist we won't wait more than 14 yrs in males.
Whether it is a constitutional delay (CDGP) or there is a serious problem in function of pituitary or testes, will start replacement with anabolic steroids/ testosterone. We will treat and wait after 3 months. In CDGP spontaneous puberty set in after that, and in pituitary/ testicular failure there won’t be any change and we have to restart testosterone treatment.
There won’t be any LH/FSH pulse before puberty and once puberty set in naturally or with treatment the pulses start.
Hope I have answered your question. If you have any further questions I will be happy to help.
Regards
Dr Ajish TP
Consultant Endocrinologist
http://www.YYYY.nlm.YYYY.YY/pubmed/0000
http://www.ncbi.YYY.nih.YYY/pubmed/0000
These links suggest there are LH/FSH in prepuberty? Please advise
Regards
XXXX
See detailed answer
Detailed Answer:
Hi XXXX,
Welcome back.
If you look back at my answer or previous endocrinologist answers, none has written the answer as ZERO levels. There is no PHYSIOLOGICALLY SIGNIFICANT levels before pre puberty. The LH/FSH levels increase a few years before puberty and the pulses (peaks and troughs) will be established a few months later.
LH or FSH won't produce menstruation or testosterone. Pulses of LH and FSH every 30min to 3 hrs are needed for that.
If you check the LH, FSH in a child between 3-8 yrs, reports will be LH <0.01 miu/l, FSH <0.01 miu/l.
Hope I have answered your question. If you have any further questions I will be happy to help.
Regards
Dr Ajish TP
Consultant Endocrinologist
In a child of 3-8, do physiologically insignificant levels of LH still lead to physiologically insignificant levels of testosterone? Because i read a study stating very low levels of testosterone during this age period is required in restraining hpg axis, proved by high LH/FSH in agonadal subjects.
Whats your valued opinion on this?
Kind Regards, XXXXXXX
This information is currently not translated into practice
Detailed Answer:
Hi XXXXXXX
I can understand your concerns.
These influences are multifactorial. There is no one to one relationship. If you look at various studies different influences on gonadal axis from prepubertal hormones to environmental endocrine disrupters are there.
What we should be interested is whether this information can be translated to clinical practice. Till now no guidelines suggest treatment with either low dose testosterone or LH, FSH in children less than 10 years. No study can be relied up on as puberty is a complex mechanism and highly variable in onset and progression. Even therapeutic intervention studies cannot be done as even in identical twins puberty can occur at different times.
Till a definite cause relationship can be established we can make just assumptions from these studies. None of which you have mentioned previously are multi ethnic double blind studies. So the their remarks can only be understood as just comments and not a real evidence.
Hope I have answered your question. If you have any further questions I will be happy to help.
Regards
Dr Ajish TP
Consultant Endocrinologist
I have one final query,
Why do high androgens during foetal life and 'mini puberty' only affect genital and brain development...yet in teenage years it affects the voice, hair follicles, bones.
Are androgen receptors not present in voice, hair follicle, bones of the baby?
Or yes they are present and bind to the androgen, but quickly become desensitized to avoid further reaction on these specific tissues?
thanks and wishing you all the best
XXXX
Both the reasons are there
Detailed Answer:
Hi XXXXXXX
Welcome back
Both the explanations are there. The amount of testosterone and the receptors are not enough to make that change. The level of receptors are more during pubertal period. Before and after the receptors are present but lesser in number. That is the reason there is no much increase in penile length at 30 or 40 yrs with testosterone injections while there is marked increase with same dose in 14-16 yrs.
Hope I have answered your questions. If you have any further queries I will be happy to help you.
Regards,
Dr Ajish TP [MD,DM]
Consultant Endocrinologist
But Sorry for inconvenience, just for confirmation, In normal babies with no genetic defects, do the androgen receptors in voice/hair follicle/bone ever become NIL in quantity over prolonged period of time? Or there is ALWAYS ALWAYS present?
Thanks and Best Regards
Always present
Detailed Answer:
Hi XXXXXXX
Welcome back
These receptors are always present. Increased testosterone in a 5 yr old boy can change the voice and have hair growth. But not in an extend as a teenager
Hope I have answered your questions. If you have any further queries I will be happy to help you.
Regards,
Dr Ajish TP [MD,DM]
Consultant Endocrinologist
Is above statement true?
Many thanks and wishing you all the best
Regards, XXXXXXX
That is the possible explanation
Detailed Answer:
Hi XXXXXXX
Welcome back.
That is the probable explanation for this. Low testosterone levels and lesser number of receptors leading to lesser effects of virilisation.
Regards
Dr Ajish TP
Back to the example of 5 year old boy above, suppose he was perfectly normal for a 5 year old ie he has physiologically insignificant testosterone and much less receptors in voice/hair follicles.
Is androgen - androgen receptor binding going on here in above scenario?
Kinds Regards,
XXXX
Androgen - receptor binding will be there
Detailed Answer:
Hi XXXXXXX
Welcome back
There will be androgen - androgen receptor binding. But since there are very little androgen and androgen receptor the response will be minimal
Regards
Dr Ajish TP
Consultant Endocrinologist