Pharmacology

Question 1

What does the endocrine system consist of?

Answer 1

Ductless endocrine glands occurring at numerous locations around the body.

Question 2

What does the endocrine system regulate?

Answer 2

Nutrient metabolism and the H2O/electrolyte balance

Question 3

What are functions of the endocrine system?

Answer 3

Enable change to stress
Promoting growth and development
Controlling reproduction
Regulate RBC production
Control/integrate activities of other systems

Question 4

What is autocrine signaling?

Answer 4

The cells that secretes (A) is effected by (A)

Question 5

What is paracrine signaling?

Answer 5

(A) is secreted and directly acts upon other cells

Question 6

What is endocrine signaling?

Answer 6

(A) is secreted into the blood stream and travels to target cells

Question 7

Describe (Glyco)proteins

Answer 7

Amino acid chains

e.g. Oxytocin, Insulin

Question 8

Give examples of steroids

Answer 8

Derived from cholesterol

e.g. cortisol, testosterone

Question 9

Give examples of Tyrosine and tryptophan derivatives

Answer 9

e.g. adrenaline (epinephrine) thyroid hormones, melatonin

Question 10

What are amines?

Answer 10

Pre-synthesized, stored in vesicles, released in response to stimuli by Ca2+-dependent exocytosis.
They are hydrophilic and travel free in plasma

Question 11

Describe peptides and proteins

Answer 11

Pre-synthesized usually from a long precursor, stored in vesicles, released in response to stimuli by Ca2+ - dependant exocytosis.
They are hydrophilic and travel free in plasma

Question 12

Describe steroids

Answer 12

Synthesized and secreted on demand. Cholesterol is converted to pregnenolone.
Hydrophobic, they are transported in plasma mainly bound to plasma proteins, only free if biologically active.

Question 13

What is relatively insoluble in plasma?

Answer 13

Steroids and thyroxine

Question 14

What binds cortisol?

Answer 14

Cortisol-Binding globulin (CBG)

Question 15

What binds thyroxine (T4)

Answer 15

thyroxine - binding globulin (TBG)

Question 16

Whats binds testosterone, and also estradiol?

Answer 16

Sex steroid-binding globulin (SSBG)

Question 17

What does albumin bind?

Answer 17

many steroids and thyroxine

Question 18

What does transthyretin bind?

Answer 18

Thyroxine and some steroids

Question 19

What are cell surface receptors?

Answer 19

G-protein coupled receptors

Receptor kinases

Question 20

What are nuclear receptors?

Answer 20

Intracellular receptors

Question 21

What are class 1 nuclear receptors?

Answer 21

Activated by many steroid hormones.
In absence of activating ligand they are located in cytoplasm bound to inhibitory heat shock proteins. Move to nucleus once activated

Question 22

What are class2 nuclear receptors?

Answer 22

Activated by most lipids, constitutively present in the nucleus

Question 23

What are hybrid class nuclear receptors?

Answer 23

activated by thyroid hormone (T3) and other substances - similar to class 1 in function

Question 24

What does binding of insulin cause?

Answer 24

autophosphorylation of intracellular tyrosine residues

Question 25

What does SUR1 regulate?

Answer 25

Potassium channel activity

Question 26

What forms potassium selective ion channel?

Answer 26

tetramer of Kir6.2

Question 27

What happens when ATP binds to Kir6.2?

Answer 27

The channel closes and there is depolarization of the beta cell and insulin is released

Question 28

What opens the potassium ion channel channel?

Answer 28

ADP-Mg2+ binding to the SUR1 which maintains the resting potential of the beta cell and inhibits insulin secretion.

Question 29

What do SU's used in T2DM do to the potassium ion channel?

Answer 29

Close the channel by causing depolarization and insulin release independant of plasme glucose concentration

Question 30

Give some examples of Sulfonylureas?

Answer 30

Tolbutamide Glibeclamide Glyburide Glipizide

Question 31

How do SU's act?

Answer 31

The displace the binding of ADP-Mg2+ from the SUR1 subunit.

Question 32

What can go wrong with SU's?

Answer 32

Hypog | Weight gain

Question 33

How do Glinides (Meglitinides) work?

Answer 33

Bind to SUR1 to close the K+ channeland trigger insulin release

Question 34

What are some examples of Glinides?

Answer 34

Repaglinide | Nateglinide

Question 35

What does ingestion of food stimulate?

Answer 35

Release of GLP-1 and GIP from enteroendocrine cells in small intestine.

Question 36

Where are L and K cells found?

Answer 36

``` L = ileum + colon K = jejunum + duodenum ```

Question 37

What do GLP-1 and GIP cells do?

Answer 37

Insulin release from pancreatic beta-cells and delay gastric emptying GLP-1 also decreases glucagon from pancreatic alpha-cells