TY - JOUR
T1 - Dopamine and norepinephrine in the alimentary tract changes after chemical sympathectomy and surgical vagotomy
AU - Orloff, L. A.
AU - Orloff, M. S.
AU - Bunnett, N. W.
AU - Walsh, J. H.
N1 - Funding Information:
Supported by NIH grants PM \]729~ and 17328, and ~¢RC fund.~. L.A. Orloff received an AGA Student Summer Fellowship Aw.3rd. Anita Starlight kindly typed the ma)~,uscript.
PY - 1985/4/29
Y1 - 1985/4/29
N2 - The aim of this study was to examine the distribution of dopamine and norepinephrine in the proximal alimentary tract of the rat and to assess the contributions of sympathetic and vagal fibers to the tissue concentrations of both catecholamines. Tissues were extracted in perchloric acid and the catecholamines were separated by high pressure liquid chromatography and detected electrochemically. In untreated rats (controls) both catecholamines were concentrated in the gastric muscle but norepinephrine levels were 6-8 times higher (corpus, dopamine 35 ± 7 ng.g-1, norepinephrine 265 ± 50 ng.g-1, mean ± SE, n = 6). In the mucosa norepinephrine concentrations were 10-12 times higher (corpus, dopamine 12 ± 3 ng.g-1, norepinephrine 140 ± 26 ng.g-1). Chemical sympathectomy (6 hydroxydopamine, 100 mg.kg-1 ip 3 days) significantly reduced dopamine concentrations in muscle and norepinephrine in muscle, mucosa, pylorus and duodenum. In all tissues the effects on norepinephrine were greater. Surgical vagotomy significantly reduced dopamine concentrations in the gastric muscle, but not the mucosa. Norepinephrine concentrations in the stomach of vagotomized rats were significantly reduced only in the pylorus. Differences in the relative concentrations of dopamine and norepinephrine in gastric tissues of the normal rat and differences in the effects of sympathectomy and vagotomy suggest that dopamine and norepinephrine exist, to an extent, in separate populations of cells and that dopamine is not merely a precursor of norepinephrine. Gastric mucosal dopamine, which was mainly unaffected by either treatment, may exist in APUD cells.
AB - The aim of this study was to examine the distribution of dopamine and norepinephrine in the proximal alimentary tract of the rat and to assess the contributions of sympathetic and vagal fibers to the tissue concentrations of both catecholamines. Tissues were extracted in perchloric acid and the catecholamines were separated by high pressure liquid chromatography and detected electrochemically. In untreated rats (controls) both catecholamines were concentrated in the gastric muscle but norepinephrine levels were 6-8 times higher (corpus, dopamine 35 ± 7 ng.g-1, norepinephrine 265 ± 50 ng.g-1, mean ± SE, n = 6). In the mucosa norepinephrine concentrations were 10-12 times higher (corpus, dopamine 12 ± 3 ng.g-1, norepinephrine 140 ± 26 ng.g-1). Chemical sympathectomy (6 hydroxydopamine, 100 mg.kg-1 ip 3 days) significantly reduced dopamine concentrations in muscle and norepinephrine in muscle, mucosa, pylorus and duodenum. In all tissues the effects on norepinephrine were greater. Surgical vagotomy significantly reduced dopamine concentrations in the gastric muscle, but not the mucosa. Norepinephrine concentrations in the stomach of vagotomized rats were significantly reduced only in the pylorus. Differences in the relative concentrations of dopamine and norepinephrine in gastric tissues of the normal rat and differences in the effects of sympathectomy and vagotomy suggest that dopamine and norepinephrine exist, to an extent, in separate populations of cells and that dopamine is not merely a precursor of norepinephrine. Gastric mucosal dopamine, which was mainly unaffected by either treatment, may exist in APUD cells.
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U2 - 10.1016/0024-3205(85)90365-0
DO - 10.1016/0024-3205(85)90365-0
M3 - Article
C2 - 3921790
AN - SCOPUS:0021923857
SN - 0024-3205
VL - 36
SP - 1625
EP - 1631
JO - Life Sciences
JF - Life Sciences
IS - 17
ER -