This messenger system begins with a hormone such as GH binding to a membrane bound receptor. Since the hormone is a protein the binding event causes a shape change in the receptor, which causes a shape change in the G-Protein complex. The G-Protein complex includes alpha, beta and gamma units, as well as an attached GDP, a low energy molecule. This shape change causes the G-Protein complex to remove the attached GDP and allows a molecule of GTP to bind. The alpha subunit and attached GTP then break away and bind to the Adenylate Cyclase. This then induces a shape change in the AC. A molecule of ATP is then recruited to the AC and is adapted into cAMP by the removal of 2 of its phosphates. It is now a 2nd messenger. The cAMP then binds to a PKA causing a shape change in the PKA which changes ATP into ADP leaving a phosphate attached to the PKA. The PKA is now able to transfer a phosphate to key enzymes. For example, in the case of GH, enzymes need the phosphate for mitosis.
Because I have a family member with liver cancer, I am interested in liver function and health. We learned that transfer proteins, specifically Albumin, transport steroidal hormones to target cells so that they can perform their function. I do not know if my family member has a low or high albumin count but I decided to read on-line to get some more information. I learned that in general, serum proteins are divided into two major categories, albumin and globulin and that the globulin can be broken down into 4 subdivisions. A general blood panel will test for the total protein, albumin. globulin and albumin/globulin ratio. I reviewed the causes for high and low amounts on all categories and it seems as if liver disfunction can cause it all. Total proteins may be increased due to liver disfunction or they may be lower than normal due to liver disease. The only category that liver disfunction did not seem to cause a change was in an increase in albumin. I did learn one interesting fact. Albumin levels can be used as strong predictors of health. Low levels of albumin suggests very poor health and a "predictor of bad outcome".
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I was reading your blog Ericka and really had me interested because my grandmother passed away last august due to complication from cirrhosis of the liver, and hers was not caused by alcohol, it is actually hereditary cirrhosis of the liver. That made me want to start looking up some information about liver function and found that it is usually referred to as hereditary hemochromatosis of the liver. I know that for your case you found that the only category that liver disfunction did not seem to cause a change in was in an increase in albumin. Whereas, I found that the albumin levels fall as the synthetic function of the liver declines with worsening cirrhosis since albumin is exclusively synthesized in the liver. I did find that globulins are increased due to shunting of bacterial antigens away from the liver to lymphoid tissue. Just thought it was interested and I was told I need to go have tests done sometime in the next year as a preventitive measure, though my doctor doesn't seem to be worried.
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