HCG
- Thread starter jwreels
- Start date
DAdams91982
Board Sponsor
HCG should only be used while on... not during PCT... for it is suppressive to your HPTA function itself. Kind of counter productive. While on cycle it will keep your balls from atrophying (sp?)
Adams
Adams
LittleMonster
Banned
Is 500iu every 5day enough?
LittleMonster
Banned
Found very interesting article.Ck. this out:
HCG package insert states clearly that HCG "has no known effect of fat
mobilization, appetite or sense of hunger, or body fat distribution."
It further states, "HCG has not been demonstrated to be effective adjunctive
therapy in the treatment of obesity, it does not increase fat losses
beyond that resulting from caloric restriction. 6000 I.U. of HCG in a
single injection resulted in elevated testosterone levels for six days
after the injection. At a dosage of 1500 I.U. the pharmatestosterone
level increases by 250-300% (2.5-3fold) com-pared to the initial value.
The athlete should inject one HCG ampule every 5 days. Since the testosterone
level remains considerably elevated for several days, it is unnecessary
to inject HCG more than once every 5 days. The effective dosage for ath-
letes is usually 2000-5000 I.U. per injection and should-as al-ready
mentioned-be injected every 5 days. HCG should only be taken for a few
weeks. If HCG is taken by male athletes over many weeks and in high dosages,
it is possible that the testes will respond poorly to a later HCG intake
and a release of the body's own LH. This could result in a permanent
inadequate gonadal function.
HCG can in part cause side effects similar to those of injectable testosterone.
A higher testosterone production also goes hand in hand with an elevated
estrogen level which could result in gynecomastia. This could manifest
itself in a temporary growth of breasts or reinforce already existing
breast growth in men. Farsighted athletes thus combine HCG with an antiestrogen.
Male athletes also report more frequent erections and an increased sexual
desire. In high doses it can cause acne vulgaris and the storing of minerals
and water. The last point must especially be observed since the water
retention which is possible through the use of HCG could give the muscle
system a puffy and watery appear-ance. Athletes who have already increased
their endogenous test-osterone level by taking Clomid and intend subsequently
to take HCG could experience considerable water retention and distinct
feminization symptoms (gynecomastia, tendency toward fat de-posits on
the hips). This is due to the fact that high testosterone leads to a
high conversion rate to estrogens. In very young ath-letes HCG, like
anabolic steroids, can cause an early stunting of growth since it prematurely
closes the epiphysial growth plates. Mood swings and high blood pressure
can also be attributed to the intake of HCG.
HCG's form of administration is also unusual. The substance choriongonadotropin
is a white powdery freeze-dried substance which is usually used as a
compress. Each package, for each HCG ampule, includes another ampule
with an injection solution containing isotonic sodium chloride. This
liq-uid, after both ampules have been opened in a sterile manner, is
injected into the HCG ampule and mixed with the dried substance. The
solution is then ready for use and should be injected intra-muscularly.
If only part of the substance is injected the residual solution should
be stored in the refrigerator. It is not necessary to store the unmixed
HCG in the refrigerator; however, it should be kept out of light and
below a temperature of 25* C.
Active Life: 64 hours
Drug Class: Leutenizing Hormone (LH) - Gonadotropin
Average Dose: debatable
Acne: Yes
Water Retention: Yes, high
High Blood Pressure: Yes, HCG is a female hormone
Liver Toxic: No
Aromatization: No, but it will raise testosterone levels and increased
aromatization may occur .
HCG package insert states clearly that HCG "has no known effect of fat
mobilization, appetite or sense of hunger, or body fat distribution."
It further states, "HCG has not been demonstrated to be effective adjunctive
therapy in the treatment of obesity, it does not increase fat losses
beyond that resulting from caloric restriction. 6000 I.U. of HCG in a
single injection resulted in elevated testosterone levels for six days
after the injection. At a dosage of 1500 I.U. the pharmatestosterone
level increases by 250-300% (2.5-3fold) com-pared to the initial value.
The athlete should inject one HCG ampule every 5 days. Since the testosterone
level remains considerably elevated for several days, it is unnecessary
to inject HCG more than once every 5 days. The effective dosage for ath-
letes is usually 2000-5000 I.U. per injection and should-as al-ready
mentioned-be injected every 5 days. HCG should only be taken for a few
weeks. If HCG is taken by male athletes over many weeks and in high dosages,
it is possible that the testes will respond poorly to a later HCG intake
and a release of the body's own LH. This could result in a permanent
inadequate gonadal function.
HCG can in part cause side effects similar to those of injectable testosterone.
A higher testosterone production also goes hand in hand with an elevated
estrogen level which could result in gynecomastia. This could manifest
itself in a temporary growth of breasts or reinforce already existing
breast growth in men. Farsighted athletes thus combine HCG with an antiestrogen.
Male athletes also report more frequent erections and an increased sexual
desire. In high doses it can cause acne vulgaris and the storing of minerals
and water. The last point must especially be observed since the water
retention which is possible through the use of HCG could give the muscle
system a puffy and watery appear-ance. Athletes who have already increased
their endogenous test-osterone level by taking Clomid and intend subsequently
to take HCG could experience considerable water retention and distinct
feminization symptoms (gynecomastia, tendency toward fat de-posits on
the hips). This is due to the fact that high testosterone leads to a
high conversion rate to estrogens. In very young ath-letes HCG, like
anabolic steroids, can cause an early stunting of growth since it prematurely
closes the epiphysial growth plates. Mood swings and high blood pressure
can also be attributed to the intake of HCG.
HCG's form of administration is also unusual. The substance choriongonadotropin
is a white powdery freeze-dried substance which is usually used as a
compress. Each package, for each HCG ampule, includes another ampule
with an injection solution containing isotonic sodium chloride. This
liq-uid, after both ampules have been opened in a sterile manner, is
injected into the HCG ampule and mixed with the dried substance. The
solution is then ready for use and should be injected intra-muscularly.
If only part of the substance is injected the residual solution should
be stored in the refrigerator. It is not necessary to store the unmixed
HCG in the refrigerator; however, it should be kept out of light and
below a temperature of 25* C.
Active Life: 64 hours
Drug Class: Leutenizing Hormone (LH) - Gonadotropin
Average Dose: debatable
Acne: Yes
Water Retention: Yes, high
High Blood Pressure: Yes, HCG is a female hormone
Liver Toxic: No
Aromatization: No, but it will raise testosterone levels and increased
aromatization may occur .
LittleMonster
Banned
HCG (Human Chorionic Gonadotropin) :
Pregnyl by Organon. 5,000 to 20,000 IU (International Units) per 10 cc vials. This drug is not a steroid but it is widely used in athletics today. HCG is a natural protein hormone secreted by the human placenta and purified form the urine of pregnant women. This hormone is not a natural male hormone but mimics the natural hormone LH (Luetinising Hormone) almost identically. This LH stimulates the production of testosterone by the testis in males. Thus HCG sends the same message and results in increased testosterone production by the testis due to HCG’s effect on the leydig cells of the testis. Normally this HCG is used to treat women with certain ovarian disorders and it is used to stimulate the testis of men who may be hypogonadal. Athletes use HCG to increase the body’s own natural production of testosterone which is often depressed by long term steroid use. Also when steroids are used in high dosages they can cause false signals to the hypothalamus that results in a depressed signal to the testicles. Over a period of weeks of this depressed signal the testicles ability to respond to any signal from the pituitary becomes very weak, which results in testicular atrophy. To avoid this athletes will use HCG to keep an artificial signal going to the testis and preventing testicular atrophy.
When administered, HGC raises serum testosterone very quickly. A rise in testosterone firs appears in about two hours after injecting HCG. The second peak occurs about two to four days later. HCG therapy has been found to be very effective in the prevention of testicular atrophy and to use the body’s own biochemical stimulating mechanisms to increase plasma testosterone level during training. Some steroid users find that they have some of their best strength and size gains while using HCG in conjunction with the steroids. This may wee be due to the facts that the body has high level of natural androgens as well as the artificial steroid hormones at that time. The optimal dosage for an athlete using HCG has never been established, but it is thought hat a single shot of 1000 to 2000 IU per week will get the desired results. Cycles on the HCG should be kept down to three weeks at a time with an off cycle of at least a month in between.
For example, one might use the HCG for two to three weeks in the middle of a cycle, and for two or three weeks at the end of a cycle. It has been speculated that the prolonged use of HCG could repress the body’s own production of gonadotropins permanently. This is why the short cycles are the best way to go. The side effects from HCG use include gynecomastia, water retention, and an increase in sex drive, mood alterations, headaches, and high blood pressure. HCG raises androgen levels in males by up to 400% but it also raises estrogen levels dramatically as well. This is why it can cause a real case of gynecomastia if dosages get too elevated for that person. Another side effect seen from HCG use is morning sickness (nausea and vomiting).
There have been no cases of overdose complications with the use of HCG nor have there been any associated carcinomas, liver or renal impairment. HCG was at one point looked at to see if it could carry the AIDS virus, due to the fact that it is biologically active, but the latest word is that this could not be possible in any way. So we see how HCG be used by athletes to avoid some of the problems associated with abruptly stopping a steroid cycle.
This product is also not picked up on steroid tests, so some athletes use it to keep androgen levels high before a contest that has drug testing. HCG must be refergerated after it is mixed together, and it then has a life of about 10 weeks. It is taken intramuscularly only; this drug is often available by order of a physician if you show symptoms of hypogonadism. It is hard to find on the black market.
Pregnyl by Organon. 5,000 to 20,000 IU (International Units) per 10 cc vials. This drug is not a steroid but it is widely used in athletics today. HCG is a natural protein hormone secreted by the human placenta and purified form the urine of pregnant women. This hormone is not a natural male hormone but mimics the natural hormone LH (Luetinising Hormone) almost identically. This LH stimulates the production of testosterone by the testis in males. Thus HCG sends the same message and results in increased testosterone production by the testis due to HCG’s effect on the leydig cells of the testis. Normally this HCG is used to treat women with certain ovarian disorders and it is used to stimulate the testis of men who may be hypogonadal. Athletes use HCG to increase the body’s own natural production of testosterone which is often depressed by long term steroid use. Also when steroids are used in high dosages they can cause false signals to the hypothalamus that results in a depressed signal to the testicles. Over a period of weeks of this depressed signal the testicles ability to respond to any signal from the pituitary becomes very weak, which results in testicular atrophy. To avoid this athletes will use HCG to keep an artificial signal going to the testis and preventing testicular atrophy.
When administered, HGC raises serum testosterone very quickly. A rise in testosterone firs appears in about two hours after injecting HCG. The second peak occurs about two to four days later. HCG therapy has been found to be very effective in the prevention of testicular atrophy and to use the body’s own biochemical stimulating mechanisms to increase plasma testosterone level during training. Some steroid users find that they have some of their best strength and size gains while using HCG in conjunction with the steroids. This may wee be due to the facts that the body has high level of natural androgens as well as the artificial steroid hormones at that time. The optimal dosage for an athlete using HCG has never been established, but it is thought hat a single shot of 1000 to 2000 IU per week will get the desired results. Cycles on the HCG should be kept down to three weeks at a time with an off cycle of at least a month in between.
For example, one might use the HCG for two to three weeks in the middle of a cycle, and for two or three weeks at the end of a cycle. It has been speculated that the prolonged use of HCG could repress the body’s own production of gonadotropins permanently. This is why the short cycles are the best way to go. The side effects from HCG use include gynecomastia, water retention, and an increase in sex drive, mood alterations, headaches, and high blood pressure. HCG raises androgen levels in males by up to 400% but it also raises estrogen levels dramatically as well. This is why it can cause a real case of gynecomastia if dosages get too elevated for that person. Another side effect seen from HCG use is morning sickness (nausea and vomiting).
There have been no cases of overdose complications with the use of HCG nor have there been any associated carcinomas, liver or renal impairment. HCG was at one point looked at to see if it could carry the AIDS virus, due to the fact that it is biologically active, but the latest word is that this could not be possible in any way. So we see how HCG be used by athletes to avoid some of the problems associated with abruptly stopping a steroid cycle.
This product is also not picked up on steroid tests, so some athletes use it to keep androgen levels high before a contest that has drug testing. HCG must be refergerated after it is mixed together, and it then has a life of about 10 weeks. It is taken intramuscularly only; this drug is often available by order of a physician if you show symptoms of hypogonadism. It is hard to find on the black market.
LittleMonster
Banned
fiddler said:
not Swale is it?
LittleMonster
Banned
I can't find it anywhere.When was this?
LittleMonster
Banned
Interesting! By MOD @different board:
In the last week of the cycle 2,000IU HCG was injected I.M 3 times per week for three weeks.
Also, 20mg Nolvadex is included for six weeks.
I know many will say "that's too much HCG." NOT!!! The doc I know who works with all these big names sometimes has to use upwards of 7,500 iu 3X week for 3 weeks, 40mg Nolvadex and 100mg Clomid as well. If it's really bad, factrell may be added.
Also, let's put this "it's too much HCG" into context. If you are on HRT, you only will get a 200mg shot of test cyp every two weeks. That is a clinical dose of test. What do we use? 1,000mg PER WEEK! So, let's shitcan the "it's too much HCG" theory.
In the last week of the cycle 2,000IU HCG was injected I.M 3 times per week for three weeks.
Also, 20mg Nolvadex is included for six weeks.
I know many will say "that's too much HCG." NOT!!! The doc I know who works with all these big names sometimes has to use upwards of 7,500 iu 3X week for 3 weeks, 40mg Nolvadex and 100mg Clomid as well. If it's really bad, factrell may be added.
Also, let's put this "it's too much HCG" into context. If you are on HRT, you only will get a 200mg shot of test cyp every two weeks. That is a clinical dose of test. What do we use? 1,000mg PER WEEK! So, let's shitcan the "it's too much HCG" theory.
fiddler
Member
LM,
i think the idea is to generally use the minimum drugs necessary to do the job. Why take extra when you don't have to? All it'll do is cause your hormone levels to gyrate wildly.
try taking 250 iu 3 times a week and see what happens. if your testicles don't shrink then what is the point of taking more?
fiddler
i think the idea is to generally use the minimum drugs necessary to do the job. Why take extra when you don't have to? All it'll do is cause your hormone levels to gyrate wildly.
try taking 250 iu 3 times a week and see what happens. if your testicles don't shrink then what is the point of taking more?
fiddler
LittleMonster
Banned
Doesn't it stay in your system for 5days? Why would anyone do EOD?
Dwight Schrute
I am faster than 80% of all snakes
LittleMonster said:
There is no difference in suppression from 200mg/week compared to 1g/week. If you're supressed, thats it, LH is bottomed out. That can happen on as little as 50mg/week in some. So the theory you need more HCG because you're on more gear has zero scientific basis.
Dwight Schrute
I am faster than 80% of all snakes
fiddler said:
Exactly. And these recommendations come from clinical trial and error, not some pet theory.
LittleMonster
Banned
ManBeast said:500 IU e5d will not five as stable blood levels as say 100iu ED... That's probably one of the main reasons right thereKinda like how the Enanthate ester is active for ~14 days half life.. but most people inject every 3-4 days for optimal results.
ManBeast
good stuff.do u have anything to back this up,though...not being a smartass.just can't find stuff like that anywhere.did u see a study on this somewhere?
thanks
ManBeast
Well-known member
Grrrr... It's basic logic amigo... Think about it... You say it's "active" for 5 days right? So lets assume (probably falsely) that it decays equally. 100iu per day (out of 500).
Day 1: 500iu
Day 2: 400iu
Day 3: 300iu
Day 4: 200iu
Day 5: 100iu
Day 6: 500iu
Day 7: 400iu
etc...
Now with 250iu EOD you get
Day 1: 250iu
Day 2: 125iu
Day 3: 250iu
Day 4: 125iu
The studies HAVE been done with esterefied compounds such as Enan, EQ, etc. and their pharmacology is well doccumented. The only place where constant levels seem to not really matter is with the 17AA oral steroids, because people have reported same/similar effects from one dose vs. spreading it out (given the same daily dose). And the protocall reccomended by Swale is for HRT patients.. these people don't want their nuts shrinking... what's the point of having enough Test if your balls look like rasins?
ManBeast
Day 1: 500iu
Day 2: 400iu
Day 3: 300iu
Day 4: 200iu
Day 5: 100iu
Day 6: 500iu
Day 7: 400iu
etc...
Now with 250iu EOD you get
Day 1: 250iu
Day 2: 125iu
Day 3: 250iu
Day 4: 125iu
The studies HAVE been done with esterefied compounds such as Enan, EQ, etc. and their pharmacology is well doccumented. The only place where constant levels seem to not really matter is with the 17AA oral steroids, because people have reported same/similar effects from one dose vs. spreading it out (given the same daily dose). And the protocall reccomended by Swale is for HRT patients.. these people don't want their nuts shrinking... what's the point of having enough Test if your balls look like rasins?
ManBeast
sikdogg
Hang'n & Bang'n
By saying that it's active for 5 day are we talking about a 5-day half-life?? cuz that would totally change your decay rates...ManBeast said:
I don't think anyone want their nuts to shrink. HRT patient or not, if you're on gear your nuts will most likely shrink. Isn't this the reason for taking HCG in the first place?? Cuz even with HCG, your HTPA will still be suppressed. I think it was Bobo that said only time will allow for a full recovery. Ancilliaries are only used to mitigate the sides of HPTA suppression.
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LittleMonster
Banned
I'm assuming 5days is halflife for HCG.My main consern is if I have 2500ui/ml then it's hard to get 250ui a shot.Thats like .1ml
How about everyone post what works for them...
LittleMonster
Banned
sikdogg said:
my bottle holds just 10ml total.
LittleMonster
Banned
ManBeast said:
that would su*k a big one
spooler
New member
Yup, 250 IU per injection....... I mix a 5000IU amp with an additional 9ml of bacteriostatic water, put it in a sealed sterile vial. Keep it in the fridge. Use a slin pin, shoot subq. Insulin syringes are graduated much more accurately that the 3ml barrels that we use for juice. The graduations are 100 units/ml, and it is very easy to be extremely accurate.
If the HCG gets cloudy, discard it. I kept mine in the fridge, used 250 IU twice a week - ten weeks, no problem. It also seems to 'take the edge off' of the cycle.
Try a cycle without it, watch your nuts shink to marbles, watch much of your hard earned muscle mass evaporate after the cycle because your balls are not doing their job. Then try the same cycle with (cheap) bottle of HCG........
I won't do another long cycle without it. But that's just me.
If the HCG gets cloudy, discard it. I kept mine in the fridge, used 250 IU twice a week - ten weeks, no problem. It also seems to 'take the edge off' of the cycle.
Try a cycle without it, watch your nuts shink to marbles, watch much of your hard earned muscle mass evaporate after the cycle because your balls are not doing their job. Then try the same cycle with (cheap) bottle of HCG........
I won't do another long cycle without it. But that's just me.
LittleMonster
Banned
I wish I knew this when I place an order for my pinz.Su*ks...
ManBeast
Well-known member
Yep... I'm a huge fan of Swale's protocall... I'll be using it on my next couple runs for sure (woulda used it before... but i digress)! `cuz nothing is worse than being hornier than a whorehouse full of 16 year old boys but havin yer "boys" lookin tiny as all **** (at least for the self-esteem/confidence, LoL).
ManBeast
ManBeast
LittleMonster
Banned
I hear u 
zeromagnus
Board Supporter
The problem with the insulin syringes is that they are marked for insulin, which has a different iu to mg conversion ratio than HCG (iu is dependent on the substance).
zeromagnus
Board Supporter
Ah, just found the information I was looking for:
1 IU of insulin = 45.5 mcg of insulin
1000 mcg of HCG = 3359 IU of HCG.
Therefore...
1 IU of HCG = 0.297708 mcg of HCG.
So 1 IU of insulin is 152.83 times more massive than HCG.
Feel free to correct me if I'm wrong, but I believe you wouldn't want to use a slin pin for HCG, as the markings are calibrated for insulin, not HCG. Instead, dilute your HCG to around 250iu/ml, so the error you get using the 3ml syringe is minimized (weaker concentration = if you're off by 0.1ml, you're only off by 25iu rather than 50 or 100iu if you make the HCG at a concentration of 500iu/ml or 1000iu/ml, respectively).
1 IU of insulin = 45.5 mcg of insulin
1000 mcg of HCG = 3359 IU of HCG.
Therefore...
1 IU of HCG = 0.297708 mcg of HCG.
So 1 IU of insulin is 152.83 times more massive than HCG.
Feel free to correct me if I'm wrong, but I believe you wouldn't want to use a slin pin for HCG, as the markings are calibrated for insulin, not HCG. Instead, dilute your HCG to around 250iu/ml, so the error you get using the 3ml syringe is minimized (weaker concentration = if you're off by 0.1ml, you're only off by 25iu rather than 50 or 100iu if you make the HCG at a concentration of 500iu/ml or 1000iu/ml, respectively).
LittleMonster
Banned
u guys lost me.so which one is right?
zeromagnus
Board Supporter
If your concentration is 250iu/mg, you can use a slin pin, because the max capacity of the slin pin is 1ml, so just fill it up all the way (that is, if you are taking 250iu/injection). Now, if your concentration isn't 250iu/ml, and you want to pin 250iu, then you have to do some math (if 100iu of insulin is 1ml, and your concentration of HCG is 500iu/ml, and you want to take 250iu of HCG, then you have to use .5ml, which should be 50iu on the slin pin [please correct me if I'm wrong ManBeast]). So basically, you can use a slin pin, just know that 1iu of slin doesn't equal 1iu of HCG.
LittleMonster
Banned
what if it's 2500iu/ml? 10?
LittleMonster
Banned
I was hoping there is a way around it,but I guess not.thanks
crazydoc1
Member
The max dosing on HCG is considered by the endocrinological community to be
3,333 IU twice per week the last I checked. The numbers quipped are 200-300%
testosterone increase but the reality will relate to Leydig cell populations remaining
which will usually have an age correlation .. many other variables here too..
Its been said - but I'll say it again --- LH will still be inhibited by the HCG .... endogenous test will increase, but the LH will not be restored... hence its good to bridge the gap on PCT and fight testicular atrophy through sponsorship of endogenous
test production..
It is interesting to note that long term HCG may be selectively preferred in many people vs. LH for leydig response.
----> WEIGHT LOSS & HCG <----
In the 1970s this was a fad. There is a website dedicated to bring it back for that use with some interesting references........ Invalid Link Removed
Have a look--
Also ---- I found my natural test (low) went 373 to 652 in 6 weeks on 1,000 IU 2x week sub-q.... the prescribing paper and instructions
do say that it is IM only.... but it will work SC.... slightly difference absorption time.. remember where it is going... Cenegenics
has patients on it SC .... I have had success SC....
If you overload on it, the leydig cells will not respond to it and then you'll have a bigger issue. Over time, patients on it long
term for hypo/hyper gonadatropic hypogonadism have their doses pushed up as Test levels drop on the same dosing.
Too high a dose makes the boys very stretched, enlarged, and uncomfortable..... <grin>
3,333 IU twice per week the last I checked. The numbers quipped are 200-300%
testosterone increase but the reality will relate to Leydig cell populations remaining
which will usually have an age correlation .. many other variables here too..
Its been said - but I'll say it again --- LH will still be inhibited by the HCG .... endogenous test will increase, but the LH will not be restored... hence its good to bridge the gap on PCT and fight testicular atrophy through sponsorship of endogenous
test production..
It is interesting to note that long term HCG may be selectively preferred in many people vs. LH for leydig response.
----> WEIGHT LOSS & HCG <----
In the 1970s this was a fad. There is a website dedicated to bring it back for that use with some interesting references........ Invalid Link Removed
Have a look--
Also ---- I found my natural test (low) went 373 to 652 in 6 weeks on 1,000 IU 2x week sub-q.... the prescribing paper and instructions
do say that it is IM only.... but it will work SC.... slightly difference absorption time.. remember where it is going... Cenegenics
has patients on it SC .... I have had success SC....
If you overload on it, the leydig cells will not respond to it and then you'll have a bigger issue. Over time, patients on it long
term for hypo/hyper gonadatropic hypogonadism have their doses pushed up as Test levels drop on the same dosing.
Too high a dose makes the boys very stretched, enlarged, and uncomfortable..... <grin>
Dwight Schrute
I am faster than 80% of all snakes
crazydoc1 said:
This isn't true. HCG won't suppress by itself. It has 2 feedback loops (short and long) but it seems one doens't exert its effects in humans (as it did in animals). It was once thought that since it does mimic LH and your supplying the body with an exogneous hormone that suppression will occur but in recent studies they clarify the difference between previous studies.
Endogenous luteinizing hormone surges following administration of human chorionic gonadotropin: further evidence for lack of loop feedback in humans.
Nader S, Berkowitz AS.
Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Medical School, Houston 77030.
The existence of inhibitory short- and ultrashort-loop feedback mechanisms for luteinizing hormone (LH), while documented in animals, has been questioned in humans. Since human chorionic gonadotropin (hCG) binds to LH receptors but can be distinguished from LH in immunoassays, it is possible to identify LH surges in the face of exogenously administered hCG. The present study demonstrates LH surges at midcycle in normal volunteers and in women undergoing controlled ovarian hyperstimulation, given hCG. This provides further evidence for lack of loop feedback control of LH secretion in humans.
Inability to demonstrate an ultrashort loop feedback mechanism for luteinizing hormone in humans.
Kyle CV, Griffin J, Jarrett A, Odell WD.
Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City 84132.
hCG has biological properties similar to those of LH, but can be measured separately from LH by current radioimmunometric assays. To investigate the possible existence of an autoregulatory mechanism for LH in humans, we compared the basal LH concentrations and the LH response to a GnRH stimulus with and without prior administration of hCG. On two separate occasions, at least 1 week apart, six normal (eugonadal) males and six normal postmenopausal females were given, in random order, either 10,000 IU hCG or saline followed by iv injection of a 200-micrograms bolus of GnRH. Blood samples were then taken 30, 60, 90, 120, 180, 240, and 300 min after GnRH. Serum concentrations of LH and hCG were measured at each time by two monoclonal antibody sandwich assays developed in our laboratory. After exogenous hCG, serum hCG concentrations rose rapidly to 200-500 IU/L (15,000-35,000 pg/mL) in both the men and women, remaining at this high level throughout the study. In the men, sex steroid concentrations did not change in response to the hCG during the 9 study hours. Compared to saline-treated controls, hCG had no significant effect in either men or postmenopausal women on the basal LH concentration or the response to a GnRH bolus, as determined by peak response and area under the LH/time curve between 0-300 min after GnRH. We conclude that an ultrashort loop feedback mechanism for LH on its own secretion does not exist in humans, as assessed by the present protocol.