Cholinergic control of catecholamine release in the eel.
The perifused posterior cardinal vein of the American eel (Anguilla rostrata) releases spontaneously dopamine (DA), norepinephrine (NE), and epinephrine (E). NE and E are secreted by innervated chromaffin cells, while DA is most likely released from a component of the vascular wall. Stimulation with acetylcholine strongly enhances the release of DA and E, and to a lesser degree the release of NE. Nicotine stimulates the release of all three catecholamines. Muscarine reduces the basal release of NE. Muscarine does not prevent nicotinic stimulation of NE and E release, but abolishes the nicotine effect on DA release. The muscarinic antagonist atropine stimulates the release of NE, but not of DA and E. The beta-adrenergic receptor antagonist propranolol suppresses the acetylcholine-stimulated release of NE and E, and reduces the DA response. From these findings, it appears that (1) nicotinic receptors regulate NE and E secretion from the chromaffin cells, (2) muscarinic receptors inhibit basal NE release, and (3) acetylcholine-stimulated release of NE and E requires the interaction with adrenergic receptors. On the other hand, DA release involves both nicotinic and adrenergic receptors, while the reduction of nicotine-stimulated (but not basal) DA release involves muscarinic receptors.
Al-Kharrat
H
H
Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Weiss
U
U
Tran
Q
Q
Nibbio
B
B
Scholz
S
S
Epple
A
A
D000109:Acetylcholine / Q000378:metabolism; D000811:Anguilla / Q000378:metabolism*; D000818:Animals; D002021:Buffers; D002196:Capillaries / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism*; D019439:Chromaffin Cells / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D004837:Epinephrine / Q000097:blood; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000097:blood; D010275:Parasympathetic Nervous System / Q000502:physiology*; D011976:Receptors, Muscarinic / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000378:metabolism
D002021:Buffers; D002395:Catecholamines; D011976:Receptors, Muscarinic; D011978:Receptors, Nicotinic; D000109:Acetylcholine; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine