Indirect evidence for separate vesicular neuronal origins of norepinephrine and ATP in the rabbit vas deferens.
Various modulators of neurotransmission were examined for selective effects on the non-adrenergic or adrenergic components of neurotransmission in the vas deferens to test the hypothesis that ATP and norepinephrine are secreted from the same vesicles. The ATP receptor antagonist, arylazido aminopropionyl ATP (ANAPP), selectively depressed the non-adrenergic contraction and prazosin selectively depressed the adrenergic contraction in response to electrical stimulation. These results are consistent with the presence of two neurotransmitters, ATP and norepinephrine, which mediate neurogenic contractions. Prostaglandin E2 inhibited non-adrenergic, but enhanced adrenergic, electrically induced (10 Hz) contractions, presumably via a prejunctional mechanism. The adrenergic component of the neurogenic response was significantly more sensitive to treatment with guanethidine, guanabenz, and 6-hydroxy-dopamine. These results with a variety of agents are inconsistent with the hypothesis that the neurotransmitters. ATP and norepinephrine, are released in tandem from the same neuronal granules.
Trachte
G J
GJ
Department of Pharmacology, University of Minnesota-Duluth, School of Medicine 55812.
Binder
S B
SB
Peach
M J
MJ
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D015232:Dinoprostone / Q000378:metabolism; D004558:Electric Stimulation; D006143:Guanabenz / Q000494:pharmacology; D006145:Guanethidine / Q000494:pharmacology; D006892:Hydroxydopamines / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism* / Q000494:pharmacology; D016627:Oxidopamine; D011817:Rabbits; D013565:Sympatholytics / Q000494:pharmacology; D014649:Vas Deferens / Q000187:drug effects / Q000378:metabolism / Q000502:physiology
D006892:Hydroxydopamines; D018377:Neurotransmitter Agents; D013565:Sympatholytics; D016627:Oxidopamine; D000255:Adenosine Triphosphate; D006143:Guanabenz; D015232:Dinoprostone; D009638:Norepinephrine; D006145:Guanethidine