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Biomedical subjects

G L Ferri

Publications and source records attributed to G L Ferri.

At least 37 records · Page 2Linked to original sources
PubMed1988

2,5-Hexanedione-induced accumulations of neurofilament-immunoreactive material throughout the rat autonomic nervous system.

In rats intoxicated with 2,5-hexanedione, nerve fibres supplying virtually all visceral organs showed large numbers of densely immunoreactive accumulations of neurofilament-like material, of fusiform, elongated, smoothly tapering morphology. In the gut, round to oval, morphologically different lesions were also present, and abnormal neurofilament-immunoreactive accumulations were revealed in oesophageal terminal end-plates. An extensive damage to autonomic nerve fibres, which are largely non-myelinated, was thus revealed in 2,5-hexanedione intoxication. The observed diversity in lesion morphology may suggest heterogeneity in cytoskeletal and/or associated proteins among autonomic neurons.

Animals↗
PubMed1988

Distribution of a novel pituitary protein (7B2) in mammalian gastrointestinal tract and pancreas.

The distribution of a novel pituitary protein (7B2) was determined in the gastrointestinal tract and pancreas of four mammalian species (man, pig, guinea pig, and rat) by a specific radioimmunoassay. The highest concentrations of cross-reacting immunoreactive 7B2 (IR-7B2) were observed in the pancreas and the proximal gut (antrum or duodenum). While the intestinal concentrations varied widely among species, pancreatic IR-7B2 concentrations appeared to be similar in all four species. In the rat, pancreatic islets were found to contain high concentrations of IR-7B2 (5.73 +/- 0.14 fmol/islet, mean +/- SEM). Neonatal capsaicin treatment and enteric nerve section did not affect the concentrations of IR-7B2 in the rat intestine. Layer separation of human gut showed that IR-7B2 is mainly (71 +/- 8%) present in the epithelial fraction. Chromatographic analysis of intestinal and pancreatic extracts from the four species on Sephadex G-100 showed the presence of two immunoreactive peaks at Kav 0.3 and 0.6, but there were both inter- and intraspecies variations in the proportions of the larger and smaller molecular forms.

Animals↗
PubMed1988

Proenkephalin A-derived peptides in the human gut.

The intramural distribution of the proenkephalin A-derived peptides Leu5-enkephalin, Met5-enkephalin, Met5-enkephalin-Arg6-Phe7, and Met5-enkephalin-Arg6-Gly7-Leu8 was studied throughout the human gastrointestinal tract. A parallel distribution was found of Leu5/Met5-enkephalin, measured with a Leu5-enkephalin antiserum that cross-reacts about 30% with Met5-enkephalin, and of Met5-enkephalin-Arg6-Phe7-immunoreactivity and Met5-enkephalin-Arg6-Gly7-Leu8-immunoreactivity. In each case, high tissue concentrations were present in the submucosa and muscularis corresponding to the pyloric sphincter. Taking all different regions together, a high correlation was revealed between tissue levels of Leu5/Met5-enkephalinlike peptides and Met5-enkephalin-Arg6-Gly7-Leu8-like peptides (r = 0.89), as well as between Met5-enkephalin-Arg6-Gly7-Leu8-like peptides and Met5-enkephalin-Arg6-Phe7-like peptides (r = 0.75). Met5-enkephalin-Arg6-Phe7 immunoreactivity was accounted for by a major peak (87% +/- 3% of total immunoreactivity) coeluting with the standard peptide in Sephadex G-50 chromatography and largely composed of the authentic heptapeptide, as shown by reverse-phase high-performance liquid chromatography. Leu5/Met5-enkephalin immunoreactivity was separated by high-performance liquid chromatography into peaks composed of Leu5-enkephalin and Met5-enkephalin. Allowing for Met5-enkephalin immunoreactivity in the assay used, the apparent Leu5/Met5-enkephalin molecular ratio was approximately 1:4. The high concentration of all peptides studied at the pyloric junction suggests a rich enkephalin-containing innervation at this level, in keeping with the proposed involvement of an enkephalinergic mechanism in the control of pyloric function.

Chromatography, High Pressure Liquid↗
PubMed1988

Regional distribution of immunoreactive dynorphin A in the human gastrointestinal tract.

Immunoreactive dynorphin A (ir-Dyn A) was detected throughout the human gastrointestinal tract by a validated radioimmunoassay. Moreover, the stability of 125I-Dyn A during extraction procedures was confirmed by high performance liquid chromatography. Levels of ir-Dyn A were higher in the stomach and in the small bowel. In tissue samples separated into the main layers composing the gut wall (muscularis externa, submucosa and mucosa) ir-Dyn A was uniformly distributed. An exception was the colon, where concentrations were higher in the muscular portion. Gel permeation chromatography on samples of mucosa and muscularis externa extracts of ileum and gastric fundus, showed immunoreactive material eluting in several forms of apparently higher molecular weight than Dyn A, while only a minor peak was found to coelute with authentic Dyn A.

Digestive System↗
PubMed1988

Intramural distribution of regulatory peptides in the sigmoid-recto-anal region of the human gut.

The distribution of regulatory peptides was studied in the separated mucosa, submucosa and muscularis externa taken at 10 sampling sites encompassing the whole human sigmoid colon (five sites), rectum (two sites), and anal canal (three sites). Consistently high concentrations of VIP were measured in the muscle layer at most sites (proximal sigmoid: 286 (16) pmol/g, upper rectum: 269 (17), a moderate decrease being found in the distal smooth sphincter (151 (30) pmol/g). Values are expressed as mean (SE). Conversely, substance P concentrations showed an obvious decline in the recto-anal muscle (mid sigmoid: 19 (2.0) pmol/g, distal rectum: 7.1 (1.3), upper anal canal: 1.6 (0.6)). Somatostatin was mainly present in the sigmoid mucosa and submucosa (37 (9.3) and 15 (3.5) pmol/g, respectively) and showed low, but consistent concentrations in the muscle (mid sigmoid: 2.2 (0.7) pmol/g, upper anal canal: 1.5 (0.8]. Starting in the distal sigmoid colon, a distinct peak of tissue NPY was revealed, which was most striking in the muscle (of mid sigmoid: 16 (3.9) pmol/g, upper rectum: 47 (7.8), anal sphincter: 58 (14)). Peptide YY was confined to the mucosa and showed an earlier peak (upper sigmoid: 709 (186) pmol/g, mid-distal sigmoid: 1965 (484)). A clear differential distribution of regulatory peptides was thus shown in the region studied. A possible role is suggested for NPY and VIP containing nerves in the effector control of the human internal anal sphincter.

Aged↗
PubMed1988

Human gut neuroanatomy: methodology for a quantitative analysis of nerve elements and neurotransmitter diversity in the human "enteric nervous system".

After a few decad of neglect, the "enteric nervous system" has recently regained the attention of investigators. Indeed, various studies, such as those which led to the isolation from the gut of a number of neuropeptides, subsequently demonstrated throughout the nervous system, have prompted major advancements of modern neuroscience. In spite of a wealth of animal investigations and a number of human studies, however, available information concerning the human "enteric nervous system" is comparatively sparse. In the opinion that such lack of information was largely due to unavailability of appropriate techniques, we have initiated and developed a new comprehensive methodology. This way, a quantitative analysis was made possible of both nerve structure and transmitter status, point-to-point along the gut, as well as within the various, functionally heterogeneous components of the gastrointestinal wall itself. After a general introduction, the present review is intended to summarize such methodology, with the addition of a few illustrative examples of application and a practically-oriented guideline to its use, in the form of technical appendix.

Autonomic Nervous System↗
PubMed1987

Intramural distribution of Met5-enkephalin-Arg6-Gly7-Leu8 in sphincter regions of the human gut.

The intramural distribution of Met5-enkephalin-Arg6-Gly7-Leu8 (MERGL) was studied in the oesophago-cardiac, pyloric, ileo-caecal and sigmoid-recto-anal regions of the human digestive tract. Serial samples encompassing each area were separated into mucosa, submucosa and muscularis externa and extracted for radioimmunoassay. Comparatively low levels of MERGL immunoreactivity were measured throughout the cardiac junction. Conversely, a remarkable peak of MERGL concentration was detected at the pyloric junction, in both submucosa and muscularis. A progressive decrease in tissue levels of the same peptide, most evident in the submucosa, was detected on the proximal side of the ileo-caecal region. In the distal sigmoid colon and rectum MERGL concentrations showed a rapid decline, down to very low levels in the anal canal. The results may suggest the involvement of an enkephalinergic mechanism in the control of the human pylorus.

Cardia↗
PubMed1987

Regulatory peptide distribution in separated layers of the human jejunum.

The distribution of regulatory peptides was studied in the separated epithelium, lamina propria, submucosa and muscularis externa of the human jejunum. Gastrin, secretin, gastric inhibitory polypeptide, enteroglucagon and neurotensin immunoreactivity were almost confined to the endocrine cell-containing mucosal epithelium (greater than 98% of the total content), only minor amounts of motilin being detected in non-epithelial layers (3.6 +/- 0.7%, mean +/- SEM, n = 7). Conversely, vasoactive intestinal polypeptide, substance P and mammalian bombesin were virtually limited to non-epithelial layers (greater than 99%). Only somatostatin was found in all layers (44 +/- 6.7% in the epithelium, 34 +/- 5.2% in the lamina propria, 13 +/- 2.9% in the submucosa, and 7.9 +/- 2.8% in the muscularis). Substance P was found in higher concentrations in the mucosa, compared to submucosa and muscle (56 +/- 10, 30 +/- 4.0 and 29 +/- 4.0 pmol/g, respectively), while vasoactive intestinal polypeptide was more abundant in the muscle (411 +/- 52 pmol/g) compared to mucosa and submucosa (228 +/- 64 and 219 +/- 31 pmol/g, respectively). Only low levels of mammalian bombesin were measured, mainly in the muscle (6.9 +/- 1.5 pmol/g, or 89 +/- 3.6% of total content).

Aged↗
PubMed1987

Intramural distribution of regulatory peptides in the human stomach and duodenum.

The distribution of regulatory peptides was studied by radioimmunoassay in the separated mucosa, submucosa and muscularis externa of the human oxyntic stomach, antrum and duodenum. Immunoreactive gastrin, secretin, gastric inhibitory polypeptide and motilin were virtually confined to the mucosa and duodenal submucosa, where endocrine cells are present. Only minor amounts of motilin and gastrin (3.2 +/- 0.5% and 4.3 +/- 0.8% of their total content, means + SEM, respectively) were found in the separated duodenal muscle. Somatostatin-, vasoactive intestinal polypeptide-, substance P-, and mammalian bombesin-like peptides showed distinct differential distributions in all layers. Substance P was low in the stomach and markedly increased in the duodenum, especially in the mucosa (fundus 0.8 +/- 0.2 pmol/g, duodenum 66 +/- 12). Vasoactive intestinal polypeptide and somatostatin, although well represented in the stomach, also increased in the duodenum in all layers of the wall (whole fundus 281 +/- 33 and 334 +/- 46 pmol/g, antrum 124 +/- 18 and 426 +/- 59, duodenum 507 +/- 99 and 1816 +/- 149, respectively). Mammalian bombesin immunoreactivity was comparatively abundant in the oxyntic stomach (mucosa 34 +/- 4.5 pmol/g, muscularis externa 29 +/- 4.8), less so in the antrum (6.3 +/- 1.5 and 11 +/- 3.2 pmol/g, respectively). Low concentrations of this peptide were measured in the duodenum, practically confined to the muscle (this layer 5.1 +/- 1.5 pmol/g, or 83 +/- 5.6% of the total content).

Aged↗
PubMed1986

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 gel chromatography 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 results between species should be treated with caution.

Animals↗
PubMed1985

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.

Adult↗
PubMed1984

The effects of ileal transposition and jejunoileal bypass on food intake and GI hormone levels in rats.

Male Wistar rats received three different types of small intestinal surgery. Two groups of rats had either 10 or 20 cm of lower ileum transposed to mid-duodenum. A third comparison group of rats had 85% jejunoileal bypass. All three experimental groups showed a sustained post-operative reduction in food intake and a change in body weight gain. Measurements made 36 days after surgery showed that all experimental groups had a large increase in basal and meal-stimulated enteroglucagon. The total-integrated plasma levels of gastrin, GIP, insulin and blood glucose were significantly reduced. At sacrifice, there were large increases in the wet weight of the small intestine and pancreas. These changes were probably due to the chronic stimulation of the lower ileum with nutrient-rich chyme and may be due to the release of ileal hormones.

Animals↗
PubMed1984

VIP-, substance P- and met-enkephalin-immunoreactive innervation of the human gastroduodenal mucosa and Brunner's glands.

VIP-, substance P- and met-enkephalin-containing innervation of the human gastroduodenal mucosa and Brunner's glands was studied by immunocytochemistry on whole mount tissue preparations. A dense VIP-containing nerve supply was found around fundic and pyloric glands, while the few and scattered substance P-immunoreactive fibres tended to run across the full thickness of the gastric mucosa. In the duodenum, both VIP and substance P were present in a striking nerve network in the villi as well as in the muscularis mucosae and around blood vessels. Both peptides were also immunostained in nerve bundles and neuronal perikarya between the lobules of Brunner's glands, while only very few fibres reached the proximity of acinar cells. Met-enkephalin-immunoreactivity was detected in a small number of nerve fibres, virtually confined to the basal parts of the mucosa and to the duodenal submucous plexus.

Duodenum↗
PubMed1984

Quantification of the intestinal peptide-containing innervation: length density of nerve fibers and total length of nerve supply to the single villus/crypt unit.

The application of a morphometric method to the quantification of peptide-containing nerves in the gut is described. It allows a simple estimation of the nerve fiber supply per unit volume of tissue (length density) and the calculation of the total nerve fiber supply per unit of intestinal mucosa (villus/crypt unit).

Cell Count↗
PubMed1983

Immunocytochemistry of serotonin-containing nerves in the human gut.

An immunocytochemical technique, using L-tryptophan enhancement and paraformaldehyde fixation, has been successfully applied for the demonstration of serotonin-containing neurons in the human enteric nervous system. Throughout the intestine, serotonin-immunoreactive nerves were mainly detected in the myenteric plexus and, to a smaller extent, in the submucous plexus, while hardly any nerve fibres were seen in the mucosa. This approach provides a useful tool for the investigation of neuropathological conditions of the gut.

Fluorescent Antibody Technique↗