58 research outputs found
Intramural distribution of neuron specific enolase (NSE) in the human gastrointestinal tract.
NSE concentrations were measured by radioimmunoassay in the main separated layers
of the human gastrointestinal tract. At all levels, a similar pattern of
distribution of this protein was found, primarily parallel to that of nerve
elements. Lower amounts of NSE were detected in the separated mucosal epithelium,
containing the endocrine cells
Human distribution and release of a putative new gut hormone, peptide YY.
A radioimmunoassay has been developed for the new intestinal hormonal peptide
tyrosine tyrosine [peptide YY (PYY)]. Peptide YY concentrations were measured in
separated layers of the human gastrointestinal tract, where PYY was found
exclusively in the mucosal epithelium which contained the endocrine cells.
Peptide YY was found throughout the small intestine, in very low concentrations
(5 pmol/g) in duodenum (6 pmol/g) and jejunum (5 pmol/g), but in higher
concentrations in the terminal ileum (84 pmol/g). High concentrations were found
throughout the colon (ascending 82 pmol/g, sigmoid 196 pmol/g), being maximum in
the rectum (480 pmol/g). The major molecular form of PYY-like immunoreactivity in
human intestine appeared to be identical to pure porcine hormone, both as judged
by gel permeation chromatography and by reverse-phase high-pressure liquid
chromatography. Basal plasma concentrations of PYY were low but rose in response
to food, remaining elevated for several hours postprandially. The known potent
biologic actions of PYY, its high concentrations in gut endocrine cells, and its
release into the circulation after a normal meal suggest that this peptide may
function physiologically as a circulating gut hormone
Ileal enteroglucagon cells after ileal-duodenal transposition in the rat.
The changes occurring in the ileal wall and in enteroglucagon cells were studied
in a rat model of intestinal adaptation, obtained by the transposition of a
segment of distal ileum into the mid-duodenum (6 rats, compared with 6 transected
controls). After 40 days, the transposed ileal segment, compared to the
equivalent segment in the controls, showed striking increase in weight,
especially of the epithelium (1,585 +/- 127 vs. 305 +/- 42 mg, mean +/- SEM, p
less than 0.0005). The calculated weight of enteroglucagon cells in the segment
showed a smaller, but significant increase (1.7 +/- 0.3 vs. 0.8 +/- 0.2
micrograms, p less than 0.05). Plasma enteroglucagon was markedly raised (239 +/-
28 vs. 61 +/- 7.1 pmol/l, p less than 0.0005) and showed a greatly increased
meal-stimulated response (1,521 +/- 284 vs. 83 +/- 43 pmol, p less than 0.0005),
thus suggesting hyperactivity of enteroglucagon cells
Distribution and molecular heterogeneity of galanin in human, pig, guinea pig, and rat gastrointestinal tracts.
Galanin was measured by radioimmunoassay in whole thickness extracts of the
gastrointestinal wall from four species and in extracts from separate layers of
human small intestine. The immunoreactivity was characterized using gelchromatography and high-pressure liquid chromatography. Two antibodies were
employed, which were characterized as non-C-terminal (Gal 8) and C-terminal (Gal
9) using a C-terminal galanin 10-29 fragment. Substantial quantities of galanin
immunoreactivity were found, mainly localized at the muscle layer. Both
intramolecular and intermolecular heterogeneity was apparent. Two molecular forms
exist in humans (Kav 0.58, 0.69). The molecular heterogeneity in humans, rats,
and guinea pigs may be localized near the C-terminus of the galanin molecule. A
C-terminal extension of one human galanin form is likely (Kav 0.58). These
findings give radioimmunologic evidence for a neurocrine origin of galanin. The
chromatographic variations suggest that extrapolation of experimental result
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