Lecture 6 - Genetic Variation

Question 1

What are the main functions of steroids?

Answer 1

main biological molecule which controls homeostasis and cellular function
controls water and salt balance
controls carbohydrate and protein synthesis and metabolism
control calcium mobilisation and bone development
control development of maturation

Question 2

What condition causes excessive glucocorticoids?

Answer 2

Cushings syndrome

Question 3

What is cushing syndrome?

Answer 3

Increased fat on your chest and tummy, but slim arms and legs
build-up of fat on neck and shoulders
red puffy and rounded face
skin that bruises easily
large purple stretch marks
weakness in upper arms and thighs

Question 4

What are the MOA of glucocorticoids?

Answer 4

Glucocorticoids ENTER cells and diffuse across the plasma membrane and bind to cytoplasmic receptors
complex translocates to the nucleus to act as a transcription factor
can bind to response elements in promoter region and activate anti-inflammatory gene transcription
Can bind and repress pro-inflammatory gene activation
can interact and inhibit binding of other transcription factors (AP-1 and Nfkb) - stops them binding to the DNA and therefore they cannot drive gene transcription

Question 5

How is cortisol released?

Answer 5

Signals act on the hypothalamus to releae CRH that acts on the pituitary to stimulate the release of ACTH that acts on the adrenal hormone and we get a release of cortisol

feeds back to both the pituitary and hypothalamus to down-regulate further hormone stimulating release

Question 6

What are the anti-inflammatory effects of steroids?

Answer 6

inhibit both early and late stages of inflammation
decrease vasodilation and extravasation
inhibit cell activation
decreased production of inflammatory mediators - dampen the immune response
endogenously prevent ‘overshoot’ of immune response

Question 7

Where are endogenous corticoids released from?

Answer 7

Adrenal cortex

Question 8

Name the function of mineralcorticoid and give an example

Answer 8

Aldosterone - affect water and electrolyte balance within our body

Question 9

Name the functions of glucocorticoids and give an example

Answer 9

hydrocortisone corticosterone
affect carbohydrate and protein metabolism
anti-inflammatory and immunosuppressive effects