Question #0004
In Type II diabetes, cells have lost their sensitivity to insulin. Which of the following is the most likely mechanism of insulin insensitivity in Type II diabetics?
A) down regulation of cytosolic receptors
B) down regulation of intramembranous receptors
C) down regulation of nuclear receptors
D) down regulation plasma protein carriers
B is correct. You should know that insulin is a peptide hormone, which are water soluble. Peptide hormones thus cannot pass through the hydrophobic cell membrane and require receptors on the extracellular surface of the membrane. Because they are hydrophilic, peptide hormones do not require plasma proteins for transport in the blood. Steroid hormones have cytosolic receptors. Tyrosine derivative hormones have nuclear receptors.
I thought peptide hormones have transmembrane receptors that are on the membrane and not on the outside of the nucleus?
In Type II diabetes, cells have lost their sensitivity to insulin. Which of the following is the most likely mechanism of insulin insensitivity in Type II diabetics?
A) down regulation of cytosolic receptors
B) down regulation of intramembranous receptors
C) down regulation of nuclear receptors
D) down regulation plasma protein carriers
B is correct. You should know that insulin is a peptide hormone, which are water soluble. Peptide hormones thus cannot pass through the hydrophobic cell membrane and require receptors on the extracellular surface of the membrane. Because they are hydrophilic, peptide hormones do not require plasma proteins for transport in the blood. Steroid hormones have cytosolic receptors. Tyrosine derivative hormones have nuclear receptors.
I thought peptide hormones have transmembrane receptors that are on the membrane and not on the outside of the nucleus?
