Glucose presynaptic effects

Figure 13.2 Schematic representation of a possible ATP, purinergic, synapse. The effects of ATP, synthesised intraneuronally by mitochondrial oxidative phosphorylation from glucose, on various neuronal ATPases, are shown together with its actions as a conventional neurotransmitter acting at postsynaptic P2 and presynaptic Pj receptors...

Epinephrine and norepinephrine are catecholamines which, when released from presynaptic nerve endings, function as neurotransmitters (see here). When released from adrenal medulla in response to low blood glucose levels, epinephrine interacts with second-messenger systems in many tissues, with varied effects. In muscle, epinephrine activates adenylate cyclase, with concomitant activation of glycogenolysis and inhibition of glycogen synthesis. 

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