14: Purines

Question 1

3 types of purines

Answer 1

adenosine
ATP/ ADP
methylxantines

Question 2

endogenous purines are involved in

Answer 2

DNA/ RNA synthesis
energy metabolism
purinergic signalling

Question 3

3 families of purinergic receptors

Answer 3

1. adenosine receptors- GPCR
2. P2Y (1-14)- GPCR
3. P2X - ATP gated cation channels

Question 4

where is adenosine found

Answer 4

cell cytosol and body fluids

Question 5

cardiovascular effects of adenosiene

Answer 5

inhibits cardiac conduction
vasodilation
inhibits platelet aggregation

Question 6

CNS effects of adenosine

Answer 6

inhibitory- on neurons

Question 7

caffeine vs adenosine

Answer 7

inhibits adenosine’s inhibitory effects = stimulant

Question 8

adenosine inflammatory effects

Answer 8

pro (A1)
anti (A2
promotes mediator release form mast cells
enhances mucous secretion in lungs
bronchoconstriction
leurkcyte activation

Question 9

does adenosine inhibit or promote mediator release form mast cells

Answer 9

promote

Question 10

does adenosine cause bronchodilation

Answer 10

inhibit- causes bronchoconstriction

Question 11

theophylline treats _____ by

Answer 11

asthma by blocking A1

Question 12

methylxanthines treat ___ by

Answer 12

asthma by blocking phosphodiesterase actions = increase in cAMP = SMC relaxation = bronchodilation

Question 13

where is ADP usually found

Answer 13

cell vesicles and are exocytosed

Question 14

what is ADP’s primary receptor

Answer 14

P2Y

Question 15

what sitmulates platelet aggregation by P2Y

Answer 15

ADP

Question 16

ATP acts on

Answer 16

P2X

Question 17

which is found in the cell in high concentrations ATP or ADP

Answer 17

ATP

Question 18

ATP can be released by

Answer 18

exocytosis or channels

Question 19

what regulate K+ channels to stimulate vasodilation

Answer 19

ATP

Question 20

ATP stimulates insulin ____ at low concentrations. It ____ insulin secretion at high concentrations by _____ _____ hyperpolarization

Answer 20

secretion
decreases
beta cell

Question 21

ATP is important for ___ transmission and is a NT in the ____

Answer 21

pain

periphery

Question 22

what is released from dead/ dying cells + stimulates neutrophil chemotaxis for inflammation mediation

Answer 22

ATP