akn
Musclechemistry Member
The HPTA refers to the Hypothalamus-Pituitary-Testes-Axis. This is the endocrine systems primary androgen and testosterone making area for males (most readers already know that women do not have testes so they also lack the HPTA)
.Under normal conditions testosterone production begins when the hypothalamus senses low circulatory androgen levels such as testosterone. In response to the signal the hypothalamus secretes and releases a hormone called Gonadotropin Releasing Hormone (GnRH) that contacts receptors of the pituitary gland. As you recall, hormones and receptors are simply a method of organs, glands and tissues communicating with one another. GnRH tells the pituitary gland to secrete two gonadotropinhormones called Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH). Next, both LH and FSH enter the vascular system and take a trip down south to the testes where the leydig cells (interstitial cells and sertoli cells) are located. The mergence of LH and FSH with interstitial and sertoli cell receptor results in testosterone manufacturing and sperm production.
HPAA FUNCTION
small percentage of testosterone and other androgens come from another source called the Hypothalamus-Pituitary-Adrenal-Axis or HPAA. When the pituitary gland secretes adrenocorticotropic hormone (ACTH) the adrenal glands release a series of adrenalgenic/androgenic hormones. The main one for our point of discussion is dehydroepiandrosterone (DHEA). Through a series of enzymic interactions beginning with DHEA various other hormones are produced. These enzymic interactions are referred to as pathways. Much like a road or pathway one can imagine in life, each can lead to a different goal.
DHEA > Androstenedione > androstenediol > Testosterone
This is not to say that an elevation in DHEA will result in a corresponding elevation in testosterone. There are many enzymic reactions possible that can lead to DHEA and/or androstenedione being converted or aromatized into estrogens instead. However the ability to increase total androgen production can be done with a little work.
Testosterone exists in either a bound or unbound state. Unbound is also called free or active testosterone. The S & M team that bind testosterone and other sex hormones are sex hormone binding globulin (SHBG) and albumin. The average male produces between 6-10 mg of testosterone daily. Of that 6-10 mg only 1-2% is free or active. Think about that for a minute. Do you recall those kids in school who always seemed to be the most muscular, strongest, and fastest? They were the ones who produced the upper range of testosterone, while the rest fell somewhere below. So obviously a few extra milligrams of naturally produced testosterone can make a profound difference.
We now see that the key to a growth promoting elevation of endogenous androgens is dependent upon supercharging the HPTA and HPAA. This can be accomplished by inducing one or all of the following metabolic alterations:
(1) An increase in LH production.
(2) An increase in androgen producing substrates.
(3) An increase in free/active androgen levels.
A note of prime interest as you read on is that an increase in circulating LH levels also results in an increase in synthesis of the enzymes that favor androgen production by the HPAA and HPTA.
.Under normal conditions testosterone production begins when the hypothalamus senses low circulatory androgen levels such as testosterone. In response to the signal the hypothalamus secretes and releases a hormone called Gonadotropin Releasing Hormone (GnRH) that contacts receptors of the pituitary gland. As you recall, hormones and receptors are simply a method of organs, glands and tissues communicating with one another. GnRH tells the pituitary gland to secrete two gonadotropinhormones called Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH). Next, both LH and FSH enter the vascular system and take a trip down south to the testes where the leydig cells (interstitial cells and sertoli cells) are located. The mergence of LH and FSH with interstitial and sertoli cell receptor results in testosterone manufacturing and sperm production.
HPAA FUNCTION
small percentage of testosterone and other androgens come from another source called the Hypothalamus-Pituitary-Adrenal-Axis or HPAA. When the pituitary gland secretes adrenocorticotropic hormone (ACTH) the adrenal glands release a series of adrenalgenic/androgenic hormones. The main one for our point of discussion is dehydroepiandrosterone (DHEA). Through a series of enzymic interactions beginning with DHEA various other hormones are produced. These enzymic interactions are referred to as pathways. Much like a road or pathway one can imagine in life, each can lead to a different goal.
DHEA > Androstenedione > androstenediol > Testosterone
This is not to say that an elevation in DHEA will result in a corresponding elevation in testosterone. There are many enzymic reactions possible that can lead to DHEA and/or androstenedione being converted or aromatized into estrogens instead. However the ability to increase total androgen production can be done with a little work.
Testosterone exists in either a bound or unbound state. Unbound is also called free or active testosterone. The S & M team that bind testosterone and other sex hormones are sex hormone binding globulin (SHBG) and albumin. The average male produces between 6-10 mg of testosterone daily. Of that 6-10 mg only 1-2% is free or active. Think about that for a minute. Do you recall those kids in school who always seemed to be the most muscular, strongest, and fastest? They were the ones who produced the upper range of testosterone, while the rest fell somewhere below. So obviously a few extra milligrams of naturally produced testosterone can make a profound difference.
We now see that the key to a growth promoting elevation of endogenous androgens is dependent upon supercharging the HPTA and HPAA. This can be accomplished by inducing one or all of the following metabolic alterations:
(1) An increase in LH production.
(2) An increase in androgen producing substrates.
(3) An increase in free/active androgen levels.
A note of prime interest as you read on is that an increase in circulating LH levels also results in an increase in synthesis of the enzymes that favor androgen production by the HPAA and HPTA.
