Arimidex + High Dose Nettle Root
Is it so awful tasting that you couldn't just drop it in your mouth?
hmm...i am leaning towards considering the role of DHT in this equation...if a person has more 5A-reductase present (and that can vary wildly), the DHT will bind to SHBG more readily i believe...i reckon the same argument could be made for aromatase and estrogen. there is more than just the simple 1:1 relationship with test and SHBG.
in my experience, the results of extracted nettle products are NOT like injected testosterone, they are FAR more androgenic. i get greasier, hornier and stronger on divanil than i do with injected test...much moreso. also, my head gets much itchier, which i know for me means impending hairloss (i have the gene)
take that for what its worth. perhaps you can reverse engineer the symptoms to the cause
Androgens (and estrogens) entry,It will always be mediated by shbg
,be Megalin or SHBG-R or albumin mechanisms.
44 percent of testosterone is bound firmly to sex
hormone-binding globulin, 54 percent is bound to
albumin, and only 1-2 percent is in a free state.
J Biol Chem. 1990 Apr 15;265(11):6048-54.
The control of the interaction of sex hormone-binding globulin with its receptor by steroid hormones.
Hryb DJ, Khan MS, Romas NA, Rosner W.
Department of Medicine, St. Luke's/Roosevelt Hospital Center, College of Physicians and Surgeons, Columbia University, New York, New York 10019.
Sex hormone-binding globulins (SHBG) is a plasma glycoprotein that binds certain steroids. It, in turn, binds to a specific receptor on cell membranes. This work was undertaken to investigate the role of steroids in the interaction of SHBG with its receptor. Because the probe for the interaction of SHBG with its receptor is 125I-SHBG, we first showed that 125I-SHBG binds [3H]dihydrotestosterone (DHT) at 4 degrees C and 37 degrees C with KD values similar to those published previously for pure radioinert SHBG. 125I-SHBG could be prevented from binding to its receptor by a variety of steroids whose relative inhibitory activity (dihydrotestosterone much greater than 2-methoxyestradiol greater than testosterone greater than estradiol much greater than methyltrienolone greater than cortisol) was almost identical to their relative ability to bind to SHBG. Because significant binding of [3H]DHT to the SHBG receptor could not be demonstrated, steroid inhibition of SHBG binding must be noncompetitive. If steroids bound to SHBG prevent binding to the SHBG receptor, then liganded SHBG should have a higher apparent KD for its receptor than unliganded SHBG. This is the case. The KD was 0.86 +/- 0.25 nM for the high affinity receptor site using liganded SHBG and 0.19 +/- 0.024 nM for unliganded SHBG. Thus, only liganded SHBG assumes a conformation that prohibits interaction with the SHBG receptor. However, when unliganded SHBG was prebound to its receptor, it retained its ability to bind [3H] DHT. The model that emerges from these observations is as follows. Unliganded SHBG can bind either steroids or receptor in a reversible reaction; SHBG bound to a steroid cannot bind to the receptor*, but unliganded SHBG that first binds to the receptor can subsequently bind steroids.
*but can bind to the megalin receptor.
J Endocrinol Invest. 1999 Mar;22(3):223-34.
Sex hormone-binding globulin: not only a transport protein. What news is around the corner?
Laboratorio di Endocrinologia, II UOADU Medicina Generale, Azienda Ospedaliera S. Giovanni Battista, Torino, Italy.
The plasma Sex Hormone-Binding Globulin (SHBG) transports androgens and estradiol in the blood and regulates their bioavailable fraction and access to target cells. The recent advances in the knowledge of its structure and gene expression, and notabily the demonstration of a specific receptor (SHBG-R) located on membranes of sex steroid responsive cells, gave support to the thesis that SHBG has much more sophisticated functions at cell site. In particular, the receptor-mediated action of SHBG, which uses as a second messenger cAMP, has been linked to the effects of androgens and estradiol. It is conceivable that the SHBG/SHBG-R system works as an additional control mechanism which inhibits or amplifies the effects of DHT and estradiol in cells. In the prostate, it has been suggested that the estradiol-activated SHBG/SHBG-R complex cross-talks with the androgen receptor, and is able to activate AR even in the absence of DHT*. Of great interest, for its potential clinical applications, is the observation that in estrogen-dependent breast cancer SHBG, through SHBG-R, cAMP and PKA, specifically inhibits the estradiol-induction of cell proliferation. This anti-proliferative, anti-estrogenic effect of human SHBG has not only increased and continues to increase our understanding of the molecular mechanisms involved in the biology of breast cancer, but could also be exploited as a future therapeutic strategy in the managing of estrogen-dependent tumours.
Clin Endocrinol (Oxf). 2005 Apr;62(4):498-503.
Serum levels of sex hormone-binding globulin (SHBG) are not associated with lower levels of non-SHBG-bound testosterone in male newborns and healthy adult men.
de Ronde W, van der Schouw YT, Pierik FH, Pols HA, Muller M, Grobbee DE, Gooren LJ, Weber RF, de Jong FH.
Department of Internal Medicine, Erasmus Medical Center, 3000 DR Rotterdam, the Netherlands.
OBJECTIVE: It is generally accepted that SHBG decreases the bioavailability and activity of testosterone (T). In in vitro experiments increased levels of SHBG will be associated with decreased levels of non-SHBG bound testosterone (non-SHBG-T). However, in vivo SHBG can alter both production and clearance rates and thus plasma levels of T. DESIGN AND PATIENTS: In order to study the effect of SHBG on the levels of non-SHBG-T in vivo in the presence of an active hypothalamo-pituitary-gonadal (HPG) axis we conducted a cross sectional study in 400 healthy adult men with an age range of 40-80 years and in 106 newborn boys. MEASUREMENTS: In both groups, regression coefficients (beta) and partial correlation coefficients ® were calculated for the relationship between SHBG and T or non-SHBG-T. Adult men were divided into age groups per decade (40-50 years, 51-60 years, 61-70 years and 71-80 years) to study possible differences in the impact of SHBG on the level of non-SHBG-T throughout ageing. RESULTS: Higher levels of SHBG were associated with higher levels of total testosterone in neonates (beta = 0.02 +/- 0.004, r = 0.44, P < 0.001) but not with non-SHBG-T (beta = -0.001 +/- 0.001, r = 0.05, P = 0.52). In adult men there was a significant age related increase in levels of SHBG and an age-related decrease of both total and non-SHBG-T. Higher SHBG was strongly associated with higher total testosterone in all age groups (beta = 0.26, 0.26, 0.26 and 0.23 for 40-50 years, 51-60 years, 61-70 years and 71-80 years, respectively, P < 0.001 for all age groups). Higher SHBG was not or only slightly associated with higher non-SHBG-T beta = 0.02 (P = 0.32), beta = 0.04 (P = 0.03), beta = 0.04 (P = 0.02) and beta = 0.02 (P = 0.16) for 40-50 years, 51-60 years, 61-70 years and 71-80 years, respectively. CONCLUSIONS: In contrast to general belief, SHBG levels barely influence levels of non-SHBG-bound testosterone both in male newborns and healthy adult men: the influence, if any, is positive. Consequently the age related increase of SHBG does not account for the age related decline in non-SHBG-T in healthy adult men.
J Biol Chem. 2002 Jul 19;277(29):26618-22.
Sex hormone-binding globulin in the human prostate is locally synthesized and may act as an autocrine/paracrine effector.
Hryb DJ, Nakhla AM, Kahn SM, St George J, Levy NC, Romas NA, Rosner W.
Department of Medicine, St. Luke's/Roosevelt Hospital Center, and College of Physicians and Surgeons, Columbia University, New York, New York 10019, USA.
Sex hormone-binding globulin (SHBG) is a plasma protein synthesized and secreted by the liver. Its initial description stemmed from its ability to bind estrogens and androgens and its capacity to regulate the free concentration of the steroids that bind to it. Additionally, it participates in signal transduction for certain steroid hormones at the cell membrane. It binds with high affinity to a specific membrane receptor (R(SHBG)) in prostate stromal and epithelial cells, wherein the SHBG.R(SHBG) complex forms. An appropriate steroid binds to this complex and results in increases of intracellular cAMP. These two disparate functions of SHBG, regulation of the concentration of free steroids in plasma and signal transduction in selected tissues, raise the question of how its synthesis and secretion might be regulated so as to best perform these two disparate functions. In this paper we demonstrate that SHBG is produced in human prostate cancer cell lines (LNCaP, DU 145, and PC 3) as well as in cultured human prostate epithelial and stromal cells. In addition, in tissue sections of human prostate, we demonstrate the presence of SHBG (immunocytochemistry) and SHBG mRNA (in situ hybridization). These observations are consistent with the hypothesis that SHBG, destined to participate in signaling at the cell membrane, is locally regulated and produced.
EMBO J. 2000 Feb 15;19(4):504-12.
Crystal structure of human sex hormone-binding globulin: steroid transport by a laminin G-like domain.
Grishkovskaya I, Avvakumov GV, Sklenar G, Dales D, Hammond GL, Muller YA.
Forschungsgruppe Kristallographie, Max-Delbruck-Center for Molecular Medicine, Robert-Roessle-Strasse 10, D-13092 Berlin, Germany.
Human sex hormone-binding globulin (SHBG) transports sex steroids in blood and regulates their access to target tissues. In biological fluids, SHBG exists as a homodimer and each monomer comprises two laminin G-like domains (G domains). The crystal structure of the N-terminal G domain of SHBG in complex with 5alpha-dihydrotestosterone at 1.55 A resolution reveals both the architecture of the steroid-binding site and the quaternary structure of the dimer. We also show that G domains have jellyroll topology and are structurally related to pentraxin. In each SHBG monomer, the steroid intercalates into a hydrophobic pocket within the beta-sheet sandwich. The steroid and a 20 A distant calcium ion are not located at the dimer interface. Instead, two separate steroid-binding pockets and calcium-binding sites exist per dimer. The structure displays intriguing disorder for loop segment Pro130-Arg135. In all other jellyroll proteins, this loop is well ordered. If modelled accordingly, it covers the steroid-binding site and could thereby regulate access of ligands to the binding pocket.
i had to re-read the testimonial from earlier....nobody has really commented on it, so i figured i would...
QUOTE(coreyx)I have low serum testosterone and also low SHGB which results in pretty high and sometimes even above the normal range free testosterone levels. According to the hypothesis that free T is the important factor I should be pretty muscular and also gain a lot of muscles, right? But I don't. I'm not muscular and also don't have much strength which leads me to believe that free T isn't as important as everybody says it is..... I think that having low SHGB sucks, it's not an advantage. I have talked with somebody else on another forum who has the same problems as me. Low serum testosterone, low SHGB and high free T. He got T replacement and didn't feel better at all because his serum testosterone wasn't elevated instead his free T went even higher but it didn't make him feel any better.
....I mean if free T was such an important factor then shouldn't I be pretty muscular and strong by nature? But I'm not. The only thing which I notice is that I'm pretty hairy which sucks.
i dont think what this guy had to say has any merit. he is mistakenly equating testosterone with muscularity and strength, when common sense tells you that is NOT an accurate representation. T is responsible for a ton of different processes, of course, and muscle growth is only one of them. how big or strong you are is dependent on a host of other factors (thyroid, diet, genetics, etc)
he mentions that he is pretty hairy, which means either a) he has plenty of T, or he has average T but plenty of 5AR.
i think the argument holds, that reduction in actively binding SHBG (due to binding with androgens, lignans or what have you) generally lends itself to more circulating free T and therefore more T effects.
plenty of fat, weak guys with very high serum or free T...also plenty of skinny, weak guys with very high serume or free T. shoot, the vast majority of human beings are not especially strong or athletic or fit, but X percent (25%? bell curve?) of them have high T.
Dear mr. Oswald I have a question, if it doesn't bother you,
which binds easier to shbg (estrogen or testosterone) and
how much the shbg increases (by lignans , phytoestrogens/estrogens).
So we want to increase shbg then. We're missing out on 5-10% of our testosterone by letting it just float free around. If I do a cycle of testosterone what can I take to make sure all of the test is bound to shbg so I can get something out of the cycle?