Author L. Rea said:
The reason bromocriptine is utilized post anabolic androgenic steroids use is as a means of controlling excessive prolactin. (Please bear with me while I explain this).
When a woman’s body prepares to give birth it begins to produce a hormone called prolactin. Its job is to trigger an increase in breast and glandular tissue to produce milk for the coming baby’s sustenance. Men produce prolactin as well!
Prolactin is a single-chain protein hormone that is closely related to growth hormone (gh - growth hormone (somatropin) - ). It is secreted by so-called lactotrophs in the anterior pituitary gland. It should be noted however that is also synthesized and secreted by a broad range of other cells in the body, most prominently various immune cells, the brain and the decidua of the pregnant uterus.
Prolactin Control
In opposition to what we normally see with all of the other pituitary hormones, the hypothalamus predominantly suppresses prolactin release from the pituitary gland. In other words, there is usually a hypothalamic "Stop that" order set against the lactotroph, and prolactin is released only when the order is released. A note of interest is that If the pituitary stalk is severed, prolactin release increases, while secretion of all the other pituitary hormones decreases dramatically due to loss of hypothalamic releasing hormones. But this is an unlikely scenario for most athletes and should obviously be avoided nonetheless.
The neurotransmitter Dopamine appears to act as the top dog prolactin-inhibiting factor. Dopamine is secreted into portal blood by the hypothalamic neurons. Next it binds to receptors on lactotrophs, and inhibits both the synthesis and release of prolactin. So chemicals and drugs that interfere with dopamine release or receptor binding also increase the release of prolactin. These are called antagonists. Drugs and chemicals that either increase, act as, or potentate dopamine are agonists.
Of course there are other chemicals in the body’s Action/Reaction Factor closet that positively regulate prolactin. The major ones are GnRH, TRH (thyroid Releasing Hormone) and VIP (Vasoactive Intestinal Polypeptide). By the way, hyper-stimulation of the nipples may have a stimulatory effect upon prolactin release as well. But that is one we will leave alone.
So Why Do Non-Cross Dressing Men Produce Prolactin?
As a man ages his body begins to decrease the amount of androgens that it synthesizes. In fact many studies have shown that an average 40 year old male produces about half of the testosterone that he did when he was 18. So he possesses a lower rate of muscle anabolism yet a higher rate of fat anabolism. Many researches have claimed that this is due to normal physiological changes that occur as we progress through the years. In truth this is bullshit and supposition based upon average sedimentary individuals. I monitor the physiological indicators of athletes for a living. I can say conclusively that almost any otherwise healthy male that remains in peak condition and eats a proper diet will retain a superior androgen production profile. So this is more so a matter of choice than pre-programmed physiological events. With that said let’s get on with the why of prolactin.
Estrogen is a primary promoter of prolactin release. Of course there are other factors to consider (which we will discuss in a moment) that may trigger excessive prolactin secretion, but the normal trend toward increased prolactin release is due to increased estrogen synthesis.
More Action/Reaction
The clinical term for excessive release of prolactin is hyperprolactinemia. It is actually a relatively common disorder in humans. There are many causes that initiate the condition including prolactin-secreting tumors and therapy with certain drugs.
Males that experience hyperprolactinemia commonly develop hypogonadism (the shut down of the hpta - hypothalamic-pituitary-testicular axis - ) with decreased sperm production, decreased sex drive and impotence. Those affected normally show breast enlargement (gynecomastia), but very rarely actually lactate. The gynecomastia can initially manifest itself as an increase in fatty tissue under the lower pectorals and a puffy appearance to the areola and nipple.
A simple blood test for serum prolactin levels is commonly employed to evaluate the degree of potential feminization a male can or is experiencing. The lab results are quite simple to read, though a trained professional should interpret the results.
Normal Levels:
A. Adult: <20 ng/ml
B. Newborn: 100 to 300 (falls below 20 after 6 weeks)
C. Pregnancy
1. First Trimester: <80 ng/ml
2. Second trimester: <160 ng/ml
3. Third Trimester: <400 ng/ml
*References
Bakerman (1984) ABCs of Lab Data, p. 342
So in summery thus far we have learned that:
(1) Testosterone is a male’s primary androgen that makes him a man.
(2) Testosterone and other androgens can be converted into the female hormone estrogen by the enzyme aromatase.
(3) Adipose sites mass produce the aromatase enzyme and estrogen is anabolic to fat cells.
(4) Increased estrogen production can result in prolactin secretion.
(5) All of this in turn propagates increases adipose tissue synthesis and decreases androgen production.
(Kind of a vicious circle isn’t it?)
We are aware of the fact that elevated prolacin can inhibit HPTA function as well as can too low of a level. For this reason it should seem obvious that drugs like bromocriptine or cabergoline have a place in post-cycle regeneration. Most will find that their blood prolactin levels are elevated significanly during and the first 2-3 weeks post AAS employment. Upon discontinuance of AAS, athletes whom employed either drug beginning at the second half-life of the longest acting AAS and continued for 14 days total realized the most rapid HPTA regeneration (and a worthwile increase in libido as well). This is of course in conjunction to HCG - human chorionic gonadotropin - /Clomid therapy. Usually 2.5 mg of bromocriptine upon waking or 0.25mg cabergoline 2x weekly were notably effective when reviewing post-cycle prolactin levels and HPTA markers.
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