Charliebizz
Well-Known Member
I have a weird question I do t know if I'm going to be able to word it right. But I'm curious why free testosterone is so import if shbg transports androgens to the cellular targets. This paragraph is from a study on pub med. I can be completely off on my interpretation.
classical hormones, sex steroids or their immediate precursors are produced in steroidogenic cells of the gonads, adrenal glands, and placenta, and they are transported in the blood to their target tissues by several steroid-binding proteins [9]. The most abundant plasma protein, albumin, binds all classes of steroids nonspecifically and with low affinity and functions as a reservoir that enhances the solubility of lipophilic molecules and prolongs their biological half-life [10]. By contrast, a plasma glycoprotein, known as sex hormone-binding globulin (SHBG), binds biologically active androgens and estrogens specifically, with an affinity four to five orders of magnitude greater than that of albumin, and is found in the blood of all classes of vertebrates with the exception of birds [9]. Because of its very high ligand-binding affinity, plasma SHBG is the major plasma transport protein for biologically active androgens and estrogens [11], and changes in the blood levels of SHBG influence their plasma distribution and access to target tissues and cells [12].
Would this mean that total t actual mattered more for low shbg guys. Like for me my tt is around 500-600 but my ft is over the top of the range on the quest test 35-155 pg/ml
But I do not get many benefits from trt.
So is shbg the most important protein for driving t into the cells? Or is something else? Or in layman's terms is free t just floating around and gets picked up by androgen receptors lol. I've always had trouble understanding why free hormones are labeled as the " gold standard " of testing.
classical hormones, sex steroids or their immediate precursors are produced in steroidogenic cells of the gonads, adrenal glands, and placenta, and they are transported in the blood to their target tissues by several steroid-binding proteins [9]. The most abundant plasma protein, albumin, binds all classes of steroids nonspecifically and with low affinity and functions as a reservoir that enhances the solubility of lipophilic molecules and prolongs their biological half-life [10]. By contrast, a plasma glycoprotein, known as sex hormone-binding globulin (SHBG), binds biologically active androgens and estrogens specifically, with an affinity four to five orders of magnitude greater than that of albumin, and is found in the blood of all classes of vertebrates with the exception of birds [9]. Because of its very high ligand-binding affinity, plasma SHBG is the major plasma transport protein for biologically active androgens and estrogens [11], and changes in the blood levels of SHBG influence their plasma distribution and access to target tissues and cells [12].
Would this mean that total t actual mattered more for low shbg guys. Like for me my tt is around 500-600 but my ft is over the top of the range on the quest test 35-155 pg/ml
But I do not get many benefits from trt.
So is shbg the most important protein for driving t into the cells? Or is something else? Or in layman's terms is free t just floating around and gets picked up by androgen receptors lol. I've always had trouble understanding why free hormones are labeled as the " gold standard " of testing.