#pharmacology-#cilostazol |#dipyridamol | #phosphidiestersaseinhibiters #mechanismofaction by #Druut
Anti-platelets pharmacology so in this lecture we will talk about the mechanism of fraction of cellostazole and diparidamole before we go uh to study the mechanism of action let us know a little bit that how the platelets aggregate generally if we understand that how the platelets aggregate then it will be easy for us to understand the mechanism of action of
These two medications you know adp thromboxine a2 and 5-hydroxytryptamine these are called as platelet aggregating factors means they are helping in the aggregation of the platelet and we don’t need that let’s aggregation inside the blood vessel so what we do we give these medications in order to inhibit the platelet aggregation well how the platelet aggregation
Actually happens you know one of these irrigation factors adp here we have two platelets this is one platelet and this is another platelet so what happens this adp it will come and will bind with the receptor of this platelet it will activate this platelet then this platelet will act or will aggregate on this next platelet like this the petlet aggregation will
Happen so how this activation happens when adp binds to the receptor of this platelet which is actually gi coupled receptor this receptor will become activated now understand and keep in mind this is gi coupled receptor this will forward the signal to the adenylyte cyclase or adenylyl cyclase adenylate adenylyl same chance so then its job is to activate or convert
Atp to cyclic amp but is it is gi so what will happen atp conversion into cyclic amp will be reduced okay due to this reduction what will happen protein kinase a its activation will be also reduced so now this protein kinase a what is the job of protein kinase a its job is to add the inorganic phosphate to this wasp when the vasp is phosphorylated means when
Phosphate is added into wasp it will become inactive consider what now due to decreased activation of protein kinase a what will happen this phosphorylation of the vasp will be reduced due to which the vasp will remain active now the function of the vasops to activate a receptor noun is gp 2b 3a when this receptor is activated by the vasp what will happen now
When this gp2b3a receptor is stimulated it will in turn attach with the fibrinogen and then that fibrinogen will attach with another receptor of the same kind present on the another platelet like this the two platelets we aggregate together so what we need now we need that we do not want to do the aggregation we want to stop the aggregation in order to decrease
The aggregation we’ll give celestazole now what is the mechanism of action of these two medication these medications they will target the enzyme phosphodiesterase and these are known as phosphodiesters inhibitors so they will inhibit the phosphodiesterase what is the normal function of phosphodiesterase phosphodiesterase is actually breaking the cyclic kmp now if
It is breaking the cyclic amp what will happen protein kinase a it will be less activated due to which less phosphorylation of vascular and the vessel again it will become active when it is less phosphorylated so what we need is that we want that cyclic amp production must be increased then atp protein kinase a its activity must be increased and if its activity
Is increased then vas will be phosphorylated which will make the vasp inactive if the vasp is inactive then the vas will not send a signal to activate this gp2 b3a receptor when this receptor is not activated then it is not going rth beaming fibrinogen to another platelet means platelet aggregation will be somehow decreased so when cilostazole and diparadimol
When we give these medications these will inhibit the phosphor diastrace so when the phosphodiesterase is inhibited cyclic amp production will be increased protein kinase a production will be increased and you know the job it is supposed to add the phosphate into wasp when the phosphate is added into wasp it will cause the inactivation of the wasp and what will
Happen next these all steps vanished so then there is no any wasp available to activate receptor here so when the receptor is not activated what’s going to happen no aggregation with the another platelet so this is how our uh pseudostation antiparamole these are doing the job to reduce the aggregation of the platelets hope so you got if still you have any kind
Of question regarding the topic you can drop that in the comment box will come for the answers very soon thank you for watching
Transcribed from video
pharmacology-cilostazol |dipyridamol | phosphodiestersase inhibitors mechanism of action by Druut By Dr UUT lectures doctor uut lectures druutlectures