One type of photochemical reaction is the dissociation of a molecule into two fragments. Since it is the electrons that provide the bonding forces that hold atoms together into molecules, if the distribution of electrons within a molecule changes drastically, the bonding forces may also change.
Trade names: IntropinÂ®, DopastatÂ®, RevimineÂ®. Mechanistic Class: sympathomimetic, dopaminergic and Î² 1 -adrenergic agonist. Therapeutic Class: vasopressor. Mechanism of action: Dopamine is a natural catecholamine neurotransmitter and is the biological precursor to norepinephrine.It increases heart rate, cardiac contractility and blood pressure by multiple mechanisms. Dopamine causes norepinephrine release from sympathetic nerve endings.echanism of action: Dopamine is a natural catecholamine neurotransmitter and is the biological precursor to norepinephrine. It increases heart rate, cardiac contractility and blood pressure by multiple mechanisms.
dopamine. a compound produced by the decarboxylation of dopa; it is the direct precursor in the synthesis of norepinephrine and is also a neurotransmitter in the central nervous system. neurotransmitter, especially within the brain, in pathways related to the co-ordination of movement and to behaviour and emotion; deficiency of dopamine in the brain is associated with Parkinson's disease.