Need a Reference on estrogen & A2 receptors

[fawnmarie]

Can anyone give me a reference to online information on the effect of estrogen on the density of A2 receptors - something that ISN'T a website trying to sell something and is simple enough for an idiot (or a 2-month endocrinology student) to understand?

Everything I find is either a commercial or WAAAYYYY over this person's head.


Fawn

 

[MS]

Not sure there is an absolute answer to your question. Although estrogens and progesterone may be associated with differences in site-specific fat accumulation in women and sex hormones may influence the activity (most likely, the number) of the adrenergic receptors on fat cells, this has not yet been confirmed in humans. Sex hormones also influence fat and carbohydrate metabolism throughout the body, which can have indirect influences on fat accumulation and breakdown. Also, sex steroids may not be the only hormones that explain site- and gender-related differences in fat accumulation. There is some evidence that catecholamine levels differ at rest and during stress in women and men. Bearing in mind that catecholamines regulate the rate of fat breakdown/accumulation in adipose tissue, such variations in catecholamine levels may contribute to other regulatory factors (such as blood circulation).

In other words, too much estrogen/not enough test may indeed lead to a relative increase in A2 receptors over B2 in women, but it is not clear that this is a direct genomic effect of estrogen on A2 receptor density. For instance, the opposite appears to be true in men-ie too much T/lack of E can also cause a relative overabundance of A2, but in the abdominal area instead of the gluteo-femoral region. Loss of estrogen (such as menopause) also causes a shift in the balance of A2:B2 receptors in the abdominal area of women. Confused??

 

[newgirl-chargeback]

I am! Were you speaking english??? (just kidding)

 

[macrophage69alpha]

In other words, too much estrogen/not enough test may indeed lead to a relative increase in A2 receptors over B2 in women, but it is not clear that this is a direct genomic effect of estrogen on A2 receptor density. For instance, the opposite appears to be true in men-ie too much T/lack of E can also cause a relative overabundance of A2, but in the abdominal area instead of the gluteo-femoral region. Loss of estrogen (such as menopause) also causes a shift in the balance of A2:B2 receptors in the abdominal area of women. Confused??

insulin issue not an alpha2 with respect to abdominal fat in males...

notably there has been an increase in this androgenic pattern among certain females.. likely due to a low fat diet and alcohol consumption.

 

[macrophage69alpha]

with respect to A2 and estrogen agree that evidence is limited... and conflicting depending on animal model and tissue..


it may be more of an issue that women have so few beta receptors in comparison that even low to moderate A2= near complete inhibition of lipolysis.

its all ratios..

 

[MS]

"it may be more of an issue that women have so few beta receptors in comparison that even low to moderate A2= near
complete inhibition of lipolysis.

its all ratios.."

Agreed. Even before you're born, a female has more fat cells in the butt and thigh region, and these cells are low in B2 receptors from the get-go. Changes in estrogen due to ovarian production at menarche may just lead to global changes in metabolism (including insulin sensitivity issues, which increases LPL activity in A2 dense cells) that makes these cells easier to fill with fat and more resistant to fat loss. On top of that, you also have paracrine effects from estrogen produced in areas that are already high in subQ fat....this estrogen is produced locally (due to higher aromatase activity) that acts locally (to increase more fat storage) creating a viscious circle of which the A2 receptors are just one factor.

Macro-why would a low fat diet with alcohol increase androgenic abdominal fat in women??? In general, moderate alcohol consumption and a low saturated fat diets are associated with IMPROVED insulin sensitivity of the visceral adipocytes????

 

[macrophage69alpha]

Macro-why would a low fat diet with alcohol increase androgenic abdominal fat in women??? In general, moderate alcohol consumption and a low saturated fat diets are associated with IMPROVED insulin sensitivity of the visceral adipocytes????

low fat = high carb

alcohol decreases insulin sensitivity in the abdominal area (the research seems to show its tissue specific)..


the fat issue, at least during development affects hormone levels.. still looking into this. but dietary fat content affects time at which menstrual cycle begins (though one must keep in mind the influence of exogenous estrogens.. which has lowered this age across the board).. and led to skyrocketing infertiliy rates in both men and women...

am willing to venture a guess that xenoestrogens are a big problem in england.. as IVF is HUGE there.

 

[MS]

I guess you must mean excess alcohol (as in alcoholism or binge drinking) and diets high in sucrose/fructose/low in fiber??? Certainly a diet including moderate alcohol and low in fat, high in complex carbs is very protective against abdominal obesity and insulin resistant syndromes.

Clearly, high insulin levels lead to high T levels which lead to increased visceral fat in both men and women. Unfortunately for many women, an increase in insulin stimulated T does NOT lead to a decrease in estrogenic fat....they just end up with a big belly AND fat thighs I see a LOT of this happening now in very young women, and I have no doubt it is related to shitty diet (more likely high in McDonald's saturated fat and coke), excess alcohol, lack of exercise and high estrogen levels from a young age.

 

[macrophage69alpha]

Clearly, high insulin levels lead to high T levels which lead to increased visceral fat in both men and women. Unfortunately for many women, an increase in insulin stimulated T does NOT lead to a decrease in estrogenic fat....they just end up with a big belly AND fat thighs I see a LOT of this happening now in very young women, and I have no doubt it is related to shitty diet (more likely high in McDonald's saturated fat and coke), excess alcohol, lack of exercise and high estrogen levels from a young age.

differ slightly with respect to evaluation of mechanism.. however agree completely with the rest..

 

[fawnmarie]

MS -

No, not confused at all - or moreso than most people who look at this closely.

Animal studies are fine for reference - if anyone knows anything about it.

Otherwise - de nada.



Fawn