Summary
Cells adjust receptor number and sensitivity, causing resistance or hypersensitivity.
In depth
Down-regulation reduces receptor numbers after prolonged exposure; up-regulation increases. Insulin resistance arises from receptor and post-receptor defects. Desensitisation via phosphorylation and internalisation.
Cells fine-tune responsiveness by changing receptor number. Receptor mutations cause syndromes such as androgen insensitivity.
Key idea: a hormone only acts on cells that have its receptor.
Cells control their response to hormones by changing receptor number and sensitivity. Down-regulation, a reduction in receptor numbers after prolonged high hormone levels, causes desensitisation, as in insulin resistance in type 2 diabetes and tolerance to drugs. Up-regulation increases receptors when hormone is low, increasing sensitivity.
Mechanisms include internalisation of receptors by endocytosis, phosphorylation by kinases and binding of arrestins, and changed gene expression. Receptor disorders can produce disease with hormone levels normal or high: androgen insensitivity syndrome arises from an AR mutation, and nephrogenic diabetes insipidus from an ADH receptor defect.
Example: continuous GnRH exposure turns off the pituitary, which is used therapeutically, whereas pulses stimulate it.
Key idea: the effect depends on both hormone amount and receptor status.
Frequently asked questions
What is Hormone Receptor Regulation?
Cells adjust receptor number and sensitivity, causing resistance or hypersensitivity.
Which area of biology covers Hormone Receptor Regulation, and how advanced is it?
Hormone Receptor Regulation is one of the 54 topics in Reproduction & Endocrinology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Pulsatile Hormone Secretion, Endocrine Tumours, Polycystic Ovary Syndrome.
Can you give an example of Hormone Receptor Regulation?
Chronic high insulin reduces receptor numbers.
What should I learn before Hormone Receptor Regulation?
Work through the Beginner topics in Reproduction & Endocrinology first, such as Reproduction, Asexual Reproduction, Sexual Reproduction, then return to Hormone Receptor Regulation. Advanced topics assume the Intermediate vocabulary.
What topics are related to Hormone Receptor Regulation?
The closest topics to Hormone Receptor Regulation are Pulsatile Hormone Secretion, Endocrine Tumours, Polycystic Ovary Syndrome, Negative Feedback in Endocrine Control. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Hormone Receptor Regulation?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Hormone Receptor Regulation. To practise the whole of Reproduction & Endocrinology, use the Reproduction & Endocrinology quiz.
How is Hormone Receptor Regulation different from Pulsatile Hormone Secretion?
Hormone Receptor Regulation: Cells adjust receptor number and sensitivity, causing resistance or hypersensitivity. Pulsatile Hormone Secretion: GnRH and other hormones are released in pulses whose frequency encodes signalling information. Read both side by side and note what each one explains.
How should I study Hormone Receptor Regulation step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Pulsatile Hormone Secretion and explain the difference aloud. Finally, take the Reproduction & Endocrinology quiz and come back to this page for any question you miss.