What is vasomotor reversal in relation to Dale's principle?

From the Research

Vasomotor Reversal and Dale's Principle

• Vasomotor reversal refers to the phenomenon where a substance that normally causes vasodilation instead causes vasoconstriction, and vice versa 1.
• This concept is related to Dale's principle, which states that each neuron releases one and only one synaptic transmitter 2, 3.
• However, recent studies have shown that this principle may not always hold true, and that a neuron can release multiple transmitters or modulators 2, 3.
• In the context of vasomotor reversal, it is possible that the release of multiple transmitters or modulators can lead to changes in vascular tone, resulting in vasodilation or vasoconstriction 1.

Mechanisms of Vasomotor Reversal

• Endothelial dysfunction is thought to play a key role in vasomotor reversal, as it can lead to an abnormal response to acetylcholine and other vasodilators 1.
• The presence of atherosclerotic lesions can also contribute to vasomotor reversal, as it can alter the response of blood vessels to various stimuli 1.
• The release of multiple transmitters or modulators, as proposed by the expanded "Dale's Principle", can also contribute to vasomotor reversal 3.

Historical Context

• The discovery of acetylcholine by Henry Dale in 1913 was a key milestone in the understanding of chemical neurotransmission 4.
• Dale's work, along with that of Otto Loewi, led to a greater understanding of the role of acetylcholine in the autonomic nervous system and its effects on blood vessels 4.