insulin/diabetes

Question 1

what is insulin produced by

Answer 1

islet of langerhans in pancreas

Question 2

what are islet of Langerhans

Answer 2

cluster of endocrine cells scattered throughout the pancreas

Question 3

what is insulin

Answer 3

small protein, peptide hormone, two peptide chains, stored as granules

Question 4

structure of insulin

Answer 4

2 peptide chains

Question 5

what synthesises insulin

Answer 5

beta cells as proinsulin

Question 6

when is insulin released

Answer 6

as response to high blood glucose levels

Question 7

other stimuli of insulin:

Answer 7

amino acids, fatty acids, parasympathetic nervous system, peptide hormones

Question 8

what is insulin stored as

Answer 8

hexamers

Question 9

what is a hexamer

Answer 9

3 dimers associating to form a hexamer stabilised by 2 zinc ions

Question 10

what is a dimer

Answer 10

2 insulin molecules bonded by hydrogen bonds

Question 11

what do hexamers precipitate to form and the effects of it

Answer 11

precipitates to form crystals, increases stability and protects against proteases

Question 12

what is the process of insulin release

Answer 12

glucose enters beta cells
glucose metabolised
increase ATP/ADP intracellular ratio
K+ channels close
cell membrane depolarisation
voltage dependent Ca2+ channels open
Ca2+ influx
exocytosis of stored insulin

Question 13

what is type 1 diabetes

Answer 13

no release of insulin

Question 14

what is type 2 diabetes

Answer 14

early stages not enough is produced, later stages no response from cells

Question 15

what is insulin inhibited by

Answer 15

low blood glucose and somatostatin

Question 16

what is somatostatin

Answer 16

peptide hormone

Question 17

what is somatostatin produced by

Answer 17

delta cells, hypothalamus, GIT

Question 18

functions of insulin

Answer 18

promotes cell proliferation/tissue growth/development, promotes cell uptake of K+ and Ca2+, promotes uptake and storage of glucose/amino acids/fats after meals for fuel conservation

Question 19

anabolic action of insulin

Answer 19

mainly on liver, muscle and adipocytes via insulin receptors to decrease glucose levels

Question 20

what is anabolic action

Answer 20

mechanism of bonding smaller units together to make a bigger structure

Question 21

what is an insulin receptor

Answer 21

tyrosine kinase receptor, preformed dimer

Question 22

what are the relay proteins for insulin receptor called

Answer 22

IRS, insulin receptor substrate

Question 23

how does glucose enter cells

Answer 23

transporters

Question 24

what are glucose transporters

Answer 24

solute linked carriers of membrane transport

Question 25

two types of solute linked carrier/ glucose transporters

Answer 25

GLUT transporters (SLC2 family), sodium-glucose linked transporters (SLC5 family)

Question 26

what does uniporter mean

Answer 26

transports in one direction

Question 27

where is GLUT-1 and GLUT-3 mainly expressed

Answer 27

blood brain barrier

Question 28

where is GLUT-2 expressed

Answer 28

gut, liver, kidney, beta cells

Question 29

describe GLUT-2 transporters

Answer 29

low affinity, high capacity transporter, transport rate dependent on glucose conc, works in both directions in the liver

Question 30

where are GLUT-4 expressed

Answer 30

adipocytes and muscles, intracellular location if low insulin levels, translocate cell membrane under insulin action

Question 31

what are SGLT transporters

Answer 31

secondary active symporter transporters, indirectly require ATP, acts in partnership with GLUT-2

Question 32

where are SGLT transporters expressed

Answer 32

lumen side of intestinal and renal epithelial cells

Question 33

structure of glucagon

Answer 33

single chain peptide hormone

Question 34

where is glucagon synthesised

Answer 34

alpha cells and upper GIT

Question 35

what stimulates glucagon to be released

Answer 35

low blood glucose/amino acids/para/sympathetic nervous system

Question 36

what inhibits the secretion of glucagon

Answer 36

somatostatin, high blood glucose, fatty acids

Question 37

glucagon works via what receptor

Answer 37

glucagon receptor

Question 38

name other regulators of blood glucose levels

Answer 38

incretins, hormones- adrenaline, growth hormone, glucocorticoids

Question 39

what is incretin secreted by

Answer 39

endocrine cells of GIT when digested food reaches duodenum

Question 40

main effect of hormones like adrenaline, growth hormones and glucocorticoids

Answer 40

increase blood glucose

Question 41

what stimulates adrenaline, growth hormones and glucocorticoids

Answer 41

hypoglycaemia (low blood sugar)

Question 42

what is diabetes mellitus

Answer 42

chronic metabolic disorder characterised by high blood glucose concentration (hyperglycaemia)

Question 43

what causes diabetes mellitus

Answer 43

insulin deficiency (type 1), impaired insulin secretion and insulin resistance (type 2)

Question 44

what is glycosuria

Answer 44

glucose in urine

Question 45

what is diuresis

Answer 45

increased urine production

Question 46

symptoms of diabetes melllitus

Answer 46

glycosuria (glucose in urine), diuresis (more pee), dehydration, thirst, fatigue, blurred vision, infections

Question 47

effects of diabetes mellitus

Answer 47

ketoacidosis (diabetic coma), mainly in type 1 patients, production of ketone decreases pH causing nausea/vomiting/breathlessness/loss of consciousness

Question 48

effects of ketoacidosis

Answer 48

production of ketone bodies by liver from fatty acid breakdown decreases pH causing nausea/vomiting/breathlessness/loss of consciousness

Question 49

long term complications of diabetes

Answer 49

deterioration of blood vessel and nerves, damaged blood vessels in eyes lead to losing sight, higher risk of heart attack and stroke, nerve damage in lower limbs lead to cramps/numbness/loss of sensation, wounds take longer to heal, tissue dies, amputation

Question 50

difference between the cause of type 1 and 2 diabetes

Answer 50

type 1- autoimmune disease type 2- obesity

Question 51

treatment of type 2 diabetes

Answer 51

weight loss, oral drugs, insulin injections

Question 51

auto immunity of type 1 diabetes

Answer 51

progressive destruction of beta cells

Question 52

treatment of type 1 diabetes

Answer 52

insulin injections, islet transplant

Question 53

what causes type 2 diabetes

Answer 53

obesity, elevated fatty acids in plasma cause insulin secretions and down regulation of insulin receptors

Question 54

main side effect of insulin treatments

Answer 54

hypoglycaemia

Question 55

what is human insulin made by

Answer 55

recombinant DNA technology

Question 56

why different formulations of insulin treatments and name them

Answer 56

to achieve different peak of effect and duration of action soluble insulin- rapid/short effect insulin suspension- delayed/prolonged effect

Question 57

other (older) drugs for type 2 diabetes

Answer 57

biguanides- increases glucose uptake in muscles and reduce glucose production in liver, advantages doesnt cause hypoglycaemia sulfonylureas glitazones a-glucosidase inhibitors

Question 58

name a newer drug for type 2 diabetes

Answer 58

sodium glucose co-transporter 2 inhibitors- inhibits SGLT2 in renal proximal tubule, decrease glucose reabsorption, increases urine excretion, high risk of ketoacidosis gdipeptidylpeptidase-4 inhibitors- inactivate enzyme that degrades GLP1, increase insulin secretion

Question 59

disadvantage of using sodium glucose cotransporter 2 inhibitors

Answer 59

high risk of ketoacidosis

Question 60

pharmacological targets for developing drugs

Answer 60

glucagon receptor, free fatty acid 1, glycogen synthase kinase 3, transporter proteins, proteases, growth factors etc.