5-ht

Question 1

5-ht 1 receptors where are they used

Answer 1

main in CNS
activation results in neural inhibition and vasoconstriction
important in mood and behaviour, thermoregulation, feeding and sleeping

Question 2

5-ht in migraines

Answer 2

can cause vasoconstriction in cerebral arteries
5-hiaa found in urine of patcients with migranes
antagonists, sumitriptan

Question 3

5-ht 1 anatagonists

Answer 3

none in clinical use

methiothepin

Question 4

methiothepin what does it act on

Answer 4

all the 5-ht1 receptor subtypes

Question 5

5-ht2 receptors where do they act

Answer 5

CNS

also distributed in periphery

Question 6

agonist of 5-ht2

Answer 6

LSD

causing hallucinations

Question 7

LSD is also a

Answer 7

antagonist of the 5-ht2 recpetor in the periphery

Question 8

action of LSD

Answer 8

inhibits firing of 5-ht neurons
alters perception (sound sight)
have been reported to precipitate attacks in schizophrenia patients

Question 9

5-ht in gut what does it stimulate

Answer 9

stimulates GI motality both directly and indirectly
directly via 5-ht2 via smooth muscle contraction
indirectly via 5-ht3 and 4 receptors on enteric neurons

Question 10

what is also stimulated in the gut

Answer 10

fluid secretion and elicit nausea and vomiting by stimulating 5-ht receptors in the stomach

Question 11

peristalsis mediated by 5-ht release from what

Answer 11

chromaffin cells

by distention of the gut

Question 12

5-ht in cardiovascular system

Answer 12

action depends on size of vessel, species sympathetic activity
direct and indirect effect
direct (NO release from endothelial cells)
indirect : inhibitory nor release from sympathetic nerve terminals

Question 13

in the cardiovascular system what does injection of 5-ht do

Answer 13

initial increase in blood pressure

as large vessels contract followed by a fall as the artieriole dilate

Question 14

5- ht in platelets

Answer 14

5-ht and 5-ht2 on platelet trigger the release of more 5-ht and causes platelets to become sticky
adhesion
platelet plug

Question 15

5-ht 2 antagonists

Answer 15

methysergide

ketotifen

Question 16

the effects of methysergide and ketotifen

Answer 16

many antagonists affect other 5-HT receptors as well as a-adrenoceptors and histamine receptors
methysergide - used to treat migranes

Question 17

5-ht3 receptors where are they found

Answer 17

peripheral nervous system - invoke pain

brain - involved in vomiting reflex

Question 18

antagonists of 5-ht3

Answer 18

ondansetron

Question 19

what does ondansetron do

Answer 19

used as anti emetics

controls server vomiting and nausea in chemotherapy

Question 20

5-ht 4 receptors where are they found

Answer 20

CNS

also regulate GI motility

Question 21

antagonists of 5-ht4

Answer 21

tegaserod

Question 22

what does tegaserod do

Answer 22

treats irritable bowel syndrome

Question 23

how to regulate serotonin

Answer 23

mao inhibitors

selective 5-ht uptake inhibitors

Question 24

moa inhibitors what does it do

Answer 24

stops 5-hiaa production

Question 25

uses of regulation

Answer 25

treatment for depression
have reduced cardiotoxicity
no anticholinergic action
not toxic in overdose

Question 26

side effects to 5-ht

Answer 26

reflects a wide range of different actions in the body
including nausea
diarreha
insomnia