About methyldopacentrally acting alpha-2 agonist ,a phenylalanine derivative, antihypertensive (pregnancy-induced hypertension).mechanism of action of methyldopamethyl dopa gets metabolized in the adrenergic neurons to alpha methyl nor adrenaline which acts centrally by stimulating alpha 2 adrenergic receptors in the vasomotor centre to decrease efferent sympathetic activity and total peripheral resistance. it also inhibits renin release from the kidneys and has some direct action on blood vessels. since methyl dopa serves as an alternate substrate to l-aromatic amino acid decarboxylase it ultimately decrease the concentration of dopamine, nor-adrenaline, epinephrine and serotonin in the cns and periphery.