Autonomic nervous system ( Adronergic agonist ) Flashcards
explain the Presynaptic receptor and post synaptic receptor
- Presynaptic receptor : its located in the presynaptic membrane and its work only as regulator of the transmitter
-postsynaptic receptor : its located in the postsynaptic membrane and its work with tissues
which concept dose Adroginc receptor is follow
-Second massager : all the adroginic receptor in the body follow the concept of second massager and they are
> G Protein Linked receptor
what is the type , location , function of adroginc receptor ?
1- a1 : follows the Gq second massager
- location :
1-1 Blood vessel’s : V.c
1-2 Uterus : contraction ( but not strong for apportion )
1-3 Eye in the dilator pupil ( radial M.c) : contraction so cause Mydriasis
1-4 GIT & uriniry: in the wall > relaxtion of the wall and contraction of the sphincter
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2- a2 : follows the Gq second massager
-Location : they are presynaptic receptor so they located only in the nerves terminal , if they activated they inhibit the Norepinephrine and they called ( selective a2 agonist )
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3-B1 : follows the CAMP second massager
-location :
3-1heart > increase all the cardiac properties:
HR,contractility,conductivity,Etc
3-2:Kidney > they are responsible for secretion of Renin
3-3 : Adipocytes
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4-B2 : follows the Camp second massager , and its the main roller of fight or flight mode
-location :
4-1:Skeletal muscles :
- facilitate of the nerve muscular transmission
-increase the blood flow by v.d of the blood vessels
-potassium shift : from the blood to the muscles but could cause hypokalmia
4-2:Coronary artery > dilation
4-3: Bronchi > bronchial dilatation
4-4:Liver : gulcogen to glucose
4-5: Eye: regulating the Eye pressure by increase the secretion of Eqousumer
4-6: Uterus > relaxation of the muscles in the Emergency time to prevent apportion
NB! sometime cause Tremors
——
5-B3:follows the Camp second massager
-location : in the adipocytes tissue specifically in the upper part of the body so when its activate cause Lipolysis
in the a1 receptor its always contraction in all the locations but in wall of GIT and urinary is relaxation give the reason?
-bcs first of all the a1 work with Gq second massnger the it will activate Ip3 then ip3 will activate the Ca++ which will activate the Myosin light chain kinase and this how the contraction happens
- but in the wall of GIT and urinray the myosin light chain are absent so the Ca++ open a channel called calcium dependent potassium channel which will cause hyprploarazation duo to the potassium and how the relaxation happens
what is the classification of the sympathomimetics ?
1- according to the mechanism of action
1-1 Direct action : direct act on the receptor
1-2 indirect action : act indirectly on the receptor by increasing the Norepinephrine
1-3 by blocking the enzyme MAO which responsible for breaking down the epinephrine
—-
2- chemically
- which consist of the caticolmine ring
> drugs with the chemical structure cant Pass the BBB and cant be absorbed
- all the drugs which consist of caticol ring called»_space; caticolamine
- all the drugs which doesn’t has caticol ring called»_space; non-caticolmine
explain the Prototype of sympathomimetics ( Epinephrine)
-Epinephrine = adrenaline
— its natural in the body located in the
1- nerve terminal
2-Supra renal gland
— Chemistry of Epinephrine:
1- its caticol ring
2- its very sensitive so it can be oxidetis by light and air when its oxidation it become darker in colour and its become toxic called : Adrenochrom
— Phramcokinatiks of Epinephrine:
1- absorption: not orally bcs its water sulable and also in the intestines MAO enzyme which break it down so fast > so only though inhalation or subcouenus
2- destrbuation: goes and distributed all over the body but can pass the BBB bcs its caticol ring
3- metabolism: by MAO enzyme
4- excretion : by 2 forms > -Metanephrine , -Vanlail mandalic acid
— ROA: 1-subcountenous
2-IV( only emergency)
3- inhalation
4-intermascular ( best way )
—-Mechanism of Epinephrine:
- it will stimulate > a1 , a2,b1,b2,b3
NB! the mechanism on a2 its not that effective bcs a2 its parasympathetic
- molecular mechanism : through the 2nd massinger Gq and Camp
what is the Pharmacological effect of Epinephrine ?
1- Heart : it will positive all the heart functions like : chronotropy , inotropy
and if the dose is high > Arethmia and ventricular fibration
2- Blood pressure (Bp) : maximum : 140 systole and 90 dystol , but with Epinephrine :
> systole controlled by cardiac out put
> dystol controlled by peripheral resistance
so it will increase the systole and decrease the dystole in the therapeutic dose
- in the high dose it will increase the dystole bcs the a1 will dominate on B2 which is do V.D so the result V.C
3-bronchi (B2): it will cause broncho dilatation and V.c of the blood vessels in the bronchi which will inhibit the gland from secretion of water and stop the sputum which called :
> broncho decongtion
-4 Eye : decrease the inter ocular pressure by effecting on the cillirly blood by cuseing V.C which will results of decreasing the secretion of the Eqousumer
5- liver : increase the glycolysis so increase the blood glucose
6- hypokalima
what is the adverse effect of the Epinephrine ?
1-hypertension
2-cerebral haemorrhage
3-Tremors
4-Tachycardia >Arrhythmia > ventricular fibration
5- Acute heart failure
6- Acute pulmonary Edema( by increasing the heart contractility
what is the Contra indication of epinephrine
—- Patient with :
1- hypertension
2-C.V.S diseases
3-high dose
4- cardiac out flow obstruction like: Aortic stenosis
5- Hyper trophic obstruction cardiac Mayobothy : its case in the interventrecular Septum the width of it its normally 12 mm but in the case the Septum with ageing getting thick till reach 17 mm and block the aortic valve , so if we give Epinephrine it will increase the contractility of the heart and the blood will stay in the heart bcs the obstruction
why Epinephrine used in emergency only ?
because it has short time of duration
what is the uses of Epinephrine?
1-Acute Anephlictic shock :
its type of hypersensitive also called immediate hypersensitive its happened duo to : - Pincillen or - bee bites
- for example : Pencillin hypersensitive your penicillin goes to mast cells and destroy it which is reales the Histamine and histamine will do - sever broncho constraction and sever vasodilation
so treatment by injecting Epinephrine intermsacular in the lateral thigh because the Epinephrine will effect by
- bronchi dilatation
and
- vasoconstriction
2-Acute broncho spasm :its more happens to the kids bcs they had a small airway in the larynx so duo to coughing the larynx wall will get inflammation and edema in the wall of larynx so the airway will get closed and the kid will be hard for him to breath so we give epinephrine to do V.c of the blood vessels of the larynx wall it will decrease the secretion and the edema will disappear and bronchi dilation
3-Cardiac arrest: cardiac arerest means no effective Pules
- so we give Epinephrine Amp through IV so it will result of V.C then we do CPR
4-Local anithtics : for Anastasia with epinephrine so we do vasoconstiction of the blood vessles to stop the blood from washing the anastegic drug
expain the direct sympathomimetics
-Drug :Norepinephrine
-Drug : Norepinephrine
- it has caticol ring so > it dosnt absorptive orally and doesn’t pass BBB
- mechanism of action : stimulate : a1 and B1 but its more effective on a1 so it will make V.C of the blood vessels
- uses: to treat Acute hypotension
- ROA : intervenos infeusion ( I.V.i) for example slain or glucose solution
expain the direct sympathomimetics
-Drug :Dopamine
-Drug : Dopamine
- it has caticol ring
- mechanism of action : its work depends on the dose thats given to the patient
1- low dose : stimulate D1 receptor which located in the renal and mesenteric vascular leading to V.D and Urine out put
2-intermediate dose : stimulate B1 in the heart which will lead to increasing the cardiac out put
3- high dose : stimulate a1 and lead to V.c and hypertension
— treatment or uses for : shock state
- shock : is patient with hypotintion and empremnt of tissue perfusion so could result of ischmia and tissue damage
expain the direct sympathomimetics
-Drug : Dobutamine
- drug : Dobutamine
- its synthatic and has caticol ring
-mechanism of action : stimulate B1 in the cardiac which lead to increase the cardiac out put - uses or treatment : to treat
Cardioginc shock ، increase the systolic Bp
-Roa: IVi ( intravenous infusion) in salain or glucose
expain the direct sympathomimetics
-B2 agonist and ita advers effect
- Drug : Salbutamol , Salmeterol , Formoterol , Ritodrine
—- they are synthatic non caticolmine so they could be giving orally and BBB pass - mechanism of action : stimulate B2
- pharmacological effect :
1- V.D blood vessels of sklatel muscles
2- V.D coronary artery
3- relaxation of uterus
4- glycolysis so increasing blood glucose
5- bronchi dilatation
6- treatment or uses :
— Salmeterol > spray : for bronchial asthma
— Ritodrine or fenoterol : for utrine relaxation
—— advers effect : TTT
1- tachycardia
2- tremors
3- tolerance
