Related Experiment Video
Updated: Oct 1, 2026

Comprehensive Profiling of Dopamine Regulation in Substantia Nigra and Ventral Tegmental Area
Published on: August 10, 2012
Evidence for a dopaminergic mechanism for the prolactin inhibitory effect of atrial natriuretic factor
W K Samson1, R Bianchi, R Mogg
1Department of Physiology, University of Texas Health Science Center, Dallas.
Abstract:
Infusion of 2 nmol atrial natriuretic factor (ANF) into the third cerebroventricle of conscious, orchidectomized male rats results in a significant inhibition of prolactin (PRL) secretion. This effect is prevented by prior treatment with the dopamine receptor antagonist, domperidone. Furthermore, domperidone reverses the inhibitory effect when given after ANF infusion. The PRL-inhibiting effect is absent as well following inhibition of tyrosine hydroxylase activity. These results suggest that ANF acts centrally at least in part via an interaction with endogenous dopaminergic systems and further suggests potent neuromodulatory actions of the peptide within the hypothalamus.
Related Concept Videos
Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
Adrenergic Neurons: Neurotransmission
Synthesis: Catecholamine synthesis requires tyrosine, which is taken...
Adrenergic Receptors: β Subtype
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors have equal affinities for...
Adrenergic Agonists: Indirect-Acting Agents
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
Drugs Affecting Neurotransmitter Synthesis
Hormonal Regulation of Blood Pressure
Epinephrine and Norepinephrine
The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction while...

