| sympathomimetic | a1 bolcker | a2 blocker | B blocker | parasympathomimetic | |||||||||||||||
| 1-CVS | |||||||||||||||||||
| heart | *B1 effect :+ chronotropic effect +rate of pace maker >tacckycardia *a1 effect :1- + bl pr >reflux braddycardia by act of baroreceptors >vagal activation >(-)SA node (-) HR 2-positive intropic effect (myocardial contraction) 3-positive dromotropic effect (conductn velocity in AV node) | vasodilator effect >(-) peri resistance but not used in treat of hypertention as it has short duration 1-baroreceptor reflex > (-) vagal center of brain + of heart >tackycardia2-+ renin secretion >+ angiotensin I & II >water and salt retention + bl pr 3-in case of non selective blocker a1 ,a2 >block a2 + release of NE >w act on B! receptor >tackycardia *if drug of a effect only as phenyl ephrine >complte removal of hypertensive effect ,NE (a,B1) >B1 effect remain ,E >reverse the hypertensive effect >hypotensive | a2 + NE release >+ bl pr leading to activation of a1 receptor (a1-NE complex) *mixed blocker (a1 ,a2) prevent hypertention but not tackycardia eg phenoxybenzamine >block a1 >vasodilation (-) bl pr ,block a2 >+ NE >tackycardia *block a receptor inhibit contraction of sphincter | 1-(-) heart rate 2-(-) myocardial contractn 3-(-) conductn velocity | M2 muscarinic receptor (-) cAMP produce 1-() automaticity os SA node >bradycardia 2-+ conductn velocity in atria and () atrial refractomy 3-() conductn in AV node ,AV bundle and prolong refractory period ,large doses produce H block | ||||||||||||||
| bl vessels | *a1 >vasoconstriction + peripheral resistance >+ bl pr *B2 >vasodilation (-) bl pr (-) peri resist *a2 >vasodilation *D1 receptor >vasodilation of renal ,mesenteric ,splanchnic ,coronary vessels and cerebral arteries | 1-acute admins >slight change in bl pr due to block B1 *chronic >marked (-) in bl pressure due to 1-(-) cardiac output 2-(-) renin sec from kidney (B1) 3-inhibition of B3 receptors that + NE release *Anxiolytic effect 5-resetling of baroreceptors | M3 muscarinic effect >generalized vasodilation >due to release of NO of endothelium of arteriols >+ c GMP >() free Ca >relax of smooth mu >vasodilation ,() peri resist ,() arterial bl pr *large dosed of ACH in presence of atropine >+ bl pr due to stim of nicotinic receptor (release of E ,NE) >Ach reversal action | ||||||||||||||||
| arterial bl pr | *B1 + HR & force of contractn ,cardiac output >+ systolic bl pr *a1 >vasoconst +peri resist *B2 >vasodil (-) peri resist (effect on diastolic) *mean arterial bl pr | total coronary flow >reduced but strong (-) in cardiac work and O2 demand >useful in treat of angina | |||||||||||||||||
| 2-eye | *a1 agonist >contract of radial mus >active mydriasis 2-(-) formn of aq humour *B2 agonists + productn of aq humour 2-stim receptors in B2 receptors in ciliary mu >relaxation (-) curvature >improve far vision | (-) productn of aq humour ,(-) IOP | M3 muscarinic *contract circular mu (constrictor pupilae) >active miosis *contract ciliary muscle >+ convexity >accomodation for near vision *activation of constrictor pupilae + contraction of ciliary mu >reslt in opening canal of Schlem >drainage of aq humour >glucoma | ||||||||||||||||
| 3-res tract | *B2 >vasodilator (bronchitis) | Bronchoconstriction | contract smooth mu and + brochial sec | ||||||||||||||||
| 4-GIT | relaxn of smooth mus ,(-) peristalsis (a2 ,B1 ,B2) *contraction of sphincter ,pyloric (a1 effect) | M3 receptors + tone and amplitude of contraction & peristaltic activity of stomach and intestine ,+ GIT sec ,relax of sphincter | |||||||||||||||||
| 5-CNS | stimulation | inhibition of glucogenolytic & lipolytic effect ?>hypoglycemia >potentiate effect of insulin >coma | |||||||||||||||||
| 6-metabolic | 1-+ bl glucose 2-+ lipolysis (B3 effect ) 3-+ BMR 4-+ bl lactic acid | increase sec of glands | |||||||||||||||||