Presynaptic modulation of the release of the co-transmitters noradrenaline and ATP.
The release of both sympathetic co-transmitters, noradrenaline and ATP, is modulated via presynaptic receptors. However, the degree of the modulation may differ indicating that the ratio of the released co-transmitters changes upon presynaptic receptor activation. For example, alpha 2-autoinhibition affects the release of noradrenaline more markedly than the release of ATP. Some sympathetic axon terminals possess presynaptic P2-purinoceptors which are activated by endogenous ATP. These receptors are a novel kind of auto-receptor: they mediate a presynaptic negative feedback mechanism in which released ATP inhibits subsequent co-transmitter release.
von Kügelgen
I
I
Pharmakologisches Institut, Universität Freiburg, Germany.
Kurz
K
K
Bültmann
R
R
Driessen
B
B
Starke
K
K
D000255:Adenosine Triphosphate / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D006801:Humans; D009638:Norepinephrine / Q000378:metabolism* / Q000502:physiology; D017661:Receptors, Presynaptic / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D017661:Receptors, Presynaptic; D000255:Adenosine Triphosphate; D009638:Norepinephrine