Question

1. What effect does elevated levels of TBG have on total T4 and on free T4 values? Explain your answer

2. What is the name of the tumor associated with elevated levels of catecholamines, metanephrines, and VMA?

3. What general biochemical class of hormones is cortisol (steroid or nitrogenous)? Describe the general mechanism of action of this class of hormone.

Answer 1

1. Thyroxine binding globulin (TBG) is a globulin that binds thyroid hormones in the circulation. It is one of the three transport protiens along with transthyretin and serum albumin it is responsible for carrying the thyroid hormones thyroxine (T4) and triiodothyronine (T₃) in the bloodstream.So the Elevated levels of TBG will cause increase in the levels of total T4 and free T4 values.

2.  Phaeochromocytoma is the tumor assosiated with elevated levels of catecholamines, metanephrines, and VMA.

3. Cortisol is a group of steroid hormones. Steroid hormones cause changes within the cell by first passing through the cell membrane of the target cell. steroid hormones unlike non steroid hormones can do this because they are fat soluble. After passing through the cell membrane it enters the nucleus and bind to DNA . Then initiates the gene transcription and protein production.