In the rat vas deferens alpha-adrenoblocking agent phentolamine (1-10(-6)M) and beta-adrenoblocking agent propranolol (1-10(-6)M) activated uptake of exogenous noradrenaline--H-3 by 37 and 47% respectively and synthesis of noradrenaline--H3 from thyrosin-H3 by 72 and 48%. The rate of noradrenaline-H3 synthesis from DOPA-H3 or dopamine-H3 remains unaltered. Regulating effect of the adrenoblocking agents is carried out by means of uptake of tyrosine-H3 and noradrenaline-H3 into adrenergic neuron, i.e. at the main stages sustaining a necessary level of mediator. The rate of noradrenaline biosynthesis is supposed to be independently regulated by means of both types of adrenoreceptors in an adrenergic neuron.
Animals Dihydroxyphenylalanine