Possible role for acetylcholine as a neurotransmitter in canine penile erection.
In 15 adult dogs, the possible role of acetylcholine as a parasympathetic neurotransmitter in canine penile erection was investigated. Intracavernous injection of increasing dosages of acetylcholine (0.1-100 micrograms) induced a dose-dependent erectile response with increased arterial flow, cavernous smooth muscle relaxation, and venous occlusion. This erectile response was completely abolished after muscarinic blockade by intracavernous injection of 0.1 mg atropine. After cavernous nerve stimulation, atropine injection significantly reduced the pudendal arterial flow (by 25%) and likewise caused a significant reduction in cavernous outflow restriction. Histologic staining showed acetylcholinesterase-positive fibers around the cavernous arteries and within the cavernous erectile tissue.
Stief
C
C
Department of Urology, University of California School of Medicine, San Francisco.
Diederichs
W
W
Benard
F
F
Bosch
R
R
Aboseif
S
S
Lue
T F
TF
Tanagho
E A
EA
D000109:Acetylcholine / Q000494:pharmacology* / Q000502:physiology; D000110:Acetylcholinesterase / Q000032:analysis; D000818:Animals; D001285:Atropine / Q000494:pharmacology*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D018727:Muscarinic Antagonists; D009126:Muscle Relaxation / Q000187:drug effects; D018377:Neurotransmitter Agents; D010410:Penile Erection / Q000187:drug effects* / Q000502:physiology; D010413:Penis / Q000098:blood supply / Q000294:innervation; D012039:Regional Blood Flow / Q000187:drug effects
D018727:Muscarinic Antagonists; D018377:Neurotransmitter Agents; D001285:Atropine; D000110:Acetylcholinesterase; D000109:Acetylcholine