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.
Ergot-derived dopamine agonists are a group of medicines consisting of bromocriptine, cabergoline, dihydroergocryptine, lisuride and pergolide. They have been available on the market for many years and are mainly used to treat Parkinsonâs disease, either on their own or in combination with other medicines. Doctors should prescribe ergot-derived dopamine agonists according to the updated prescribing information. 2  Ergot-derived dopamine agonists should not be taken by patients who have had fibrosis in the heart, lungs or abdomen. 3  The absence of fibrosis in the heart should be verified before treatment is started.