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Biomedical subjects

F Sundler

Publications and source records attributed to F Sundler.

At least 523 records · Page 29Linked to original sources
PubMed1977

Somatostatin-immunoreactive cells in medullary carcinoma of the thyroid.

Ten medullary carcinomas of the thyroid were examined by immunohistochemistry using antisera against calcitonin, somatostatin, and ACTH. In addition to calcitonin cells, eight of the tumors contained somatostatin-immunoreactive cells in varying numbers. No ACTH-immunoreactive cells were found. The results indicate that thyroid medullary carcinomas often are multihormonal, and that somatostatin is common in such tumors. In contrast to calcitonin cells, somatostatin cells are not found in normal human thyroid tissue.

Adrenocorticotropic Hormone↗
PubMed1977

VIP innervation of the gallbladder.

By immunohistochemistry, vasoactive intestinal polypeptide (VIP) was localized to nerve fibres and nerve cell bodies in the gallbladder wall of several mammals, including man. There is thus a morphological basis for accepting the powerful actions of VIP on gallbladder motility as physiological. VIP (vasoactive intestinal polypeptide), first thought of as a gut hormone, has recently been localized to a widely distributed system of nerves in the gut wall 1,2. In addition, nerves displaying VIP immunoreactivity are present in the wall of brain vessels and in the hypothalamus 1,3. Among known effects of VIP are relaxation of the gallbladder and inhibition of CCK-induced gallbladder contraction4,5. These observations prompted a search for VIP in the gallbladder wall. The present report deals with the immunohistochemical demonstration of VIP nerves in the gallbladder of several species, including man.

Animals↗
PubMed1976

Ultrastructural identification of cells storing pancreatic-type glucagon in dog stomach.

The oxyntic mucosa of the dog stomach is rich in cells storing pancreatic-type glucagon. The cells were identified by immunocytochemistry and found to be indistinguishable from pancreatic A cells in the electron microscope. Ultrastructural identification of the immunoreactive cells was accomplished by the use of consecutive semithin-ultrathin sections, a technique that permitted the use of optimally fixed material.

Animals↗
PubMed1976

Fluorescence histochemistry of peptide hormone-producing cells: observations on the nitroso-naphthol method for the demonstration of tyrosine residues.

Nitroso-naphthol reacts with tyrosine residues of peptides (and probably also proteins) to yield intensely fluorescent condensation products. This reaction forms the basis of a fluorescence histochemical procedure designed to demonstrate cells that are rich in tyrosine-containing peptides or proteins. In models the method was found to be specific for p-hydroxylated phenolic compounds. Fluorescence was induced also following formaldehyde vapour fixation. With the nitroso-naphthol technique the zymogen granules of gastric chief cells, intestinal Paneth cells, pancreatic acinar cells and certain peptide hormone-secreting cells such as the GH cells in the adenohypophysis, the insulin cells of the pancreatic islets and the calcitonin cells of the thyroid gave intense fluorescence with spectral characteristics indistinguishable from those ofthe fluorophores of tyrosine-containing peptides. In addition, a population of endocrine-like cells in the antral and intestinal mucosa of certain mammals displayed fluorescence.

Animals↗
PubMed1976

Fluorescence of tryptophan-containing peptides on paper or silica gel after treatment with formaldehyde, formaldehyde-ozone or formaldehyde-hydrochloric acid.

Sensitive and specific procedures for the chromatographic detection of tryptophan and tryptophan-containing peptides are described. Formaldehyde gas induces strong and characteristic fluorescence from tryptophan and peptides with NH2-terminal tryptophan residues on silica gel. On filter-paper, the detection of small amounts of these compounds requires the additional use of an oxidant, such as ozone. Treatment with formaldehyde-hydrochloric acid was used as a method for inducing fluorescence from tryptophan-containing peptides regardless of the position of the tryptophan residue in the peptide molecule. This reaction is useful for the chromatographic demonstration of small amounts of such peptides on both paper and silica gel. The spectral properties of the fluorophores of such tryptophan-containing peptides are distinctive and serve to distinguish them from all other known biogenic compounds that are capable of giving fluorescence with formaldehyde.

Chromatography, Gel↗
PubMed1976

Pancreatic polypeptide - a postulated new hormone: identification of its cellular storage site by light and electron microscopic immunocytochemistry.

A peptide, referred to as pancreatic polypeptide (PP), has recently been isolated from the pancreas of chicken and of several mammals. PP is thought to be a pancreatic hormone. By the use of specific antisera we have demonstrated PP immunoreactivity in the pancreas of a number of mammals. The immunoreactivity was localized to a population of endocrine cells, distinct from the A, B and D cells. In most species the PP cells occurred in islets as well as in exocrine parenchyma; they often predominated in the pancreatic portion adjacent to the duodenum. In opossum and dog, PP cells were found also in the gastric mucosa. In opossum, the PP cells displayed formaldehyde - induced fluorescence typical of dopamine, whereas no formaldehyde-induced fluorescence was detected in the PP cells of mouse, rat and guinea pig. Also in these latter species, however, PP cells appear to possess amine-handling properties, a feature common to many peptide hormone-producing cells. The ultrastructure of the PP cells was defined by combining immunohistochemistry of semi-thin plastic sections with electron microscopy of adjacent ultrathin sections. PP cells show the ultrastructural features of peptide hormone-secreting cells. The PP cells of cat and dog contain fairly large, rather electron-lucent granules, and are probably identical with the previously described F cells. The PP cells of rat, guinea-pig, chinchilla and man contain small, fairly electron-dense granules. In these latter species no F cells are found. By immunoperoxidase staining of ultrathin sections, the PP immunoreactivity was found to be localized to the cytoplasmic granules. These observations provide support for the view that PP is a true pancreatic hormone.

Animals↗
PubMed1976

Diamines and polyamines in DMBA-induced breast carcinoma containing mast cells resistant to compound 48/80.

In female rats, mammary carcinoma were induced by DMBA (7,12-dimethylbenz(alpha)anthracene) administration. The activities of histidine and ornithine decarboxylases and the concentrations of histamine, putrescine and polyamines were determined in tumour extracts and urine. In the tumour tissue, formation of histamine and putrescine took place at much higher rates than in normal mammary tissue. Administration of compound 48/80 in doses that mobilized about 70% of histamine contained in the ear failed to release histamine contained in the tumour; 48/80 also failed to produce histological signs of degranulation of the tumour mast cells. It thus appears that these cells are different from mast cells in most normal tissues, a distinction that calls for further study.

Animals↗
PubMed1976

Localization of vasoactive intestinal polypeptide (VIP) to central and peripheral neurons.

The localization of the vasoactive intestinal polypeptide (VIP) has been studied with immunohistochemistry and radioimmunoanalysis. VIP immunoreactivity is present in gastrointestinal nerves, which constitute a quantitatively important nerve population that may be intrinsic to the gut wall. VIP-immunoreactive neurons are also found within the ventromedial hypothalamus and give off processes that travel latteral to the third ventricle. Results of radioimmunoanalysis strongly indicate that the immunoreactive material represents true VIP. Thus VIP, at present a gastrointestinal hormone candidate, appears to represent a new neuronal peptide occurring in both the central and peripheral nervous system.

Animals↗
PubMed1976

Effects of antrectomy or porta-caval shunting on the histamine-storing endocrine-like cells in oxyntic mucosa of rat stomach. A fluorescence histochemical, electron microscopic and chemical study.

1. The argyrophil (enterochromaffin-like) cells in the oxyntic gland area of the rat stomach contain histamine, which can be demonstrated fluorescence microscopically after exposure to gaseous OPT. After administration of L-dopa (or L-5-hydroxytryptophan), these cells produce and temporarily store dopamine (or 5-hydroxytryptamine), demonstrable by its characteristic formaldehyde-induced fluorescence. Ultrastructurally, the enterochromaffin-like cells, which have the appearance of polypeptide hormone-secreting cells, comprise two main cell types, the most predominant one having vesicular type granules (EGL cells), the second most predominant one having smaller, uniformly electron dense granules (A-like cells). 2. Rats were subjected to the following surgical treatments: antrectomy; porta-caval shunting; antrectomy+porta-caval shunting; or sham-operation. Three to eight weeks after surgery the histamine-storing cells (enterochromaffin-like cells) of the oxyntic mucosa were analysed by fluorescence histochemistry, light and (quantitative) electron microscopy, and fluorometric determination of amines. 3. After antrectomy, fluorescence histochemistry and silver staining revealed a reduced number of enterochromaffin-like cells. The histamine content in the oxyntic mucosa was reduced by about 50%. As in unoperated injection of pentagastrin seemed to mobilize histamine. Feeding or injection of insulin failed to do so in antrectomized as opposed to control rats. Ultrastructurally, the cytoplasmic granules of both endocrine-like cell types were less numerous than in the unoperated rats. The reduction in cell number and granularity was particularly conspicuous with regard to the EGL cells. 4. After porta-caval shunting the number of enterochromaffin-like cells increased markedly. Chemical determination revealed a twofold increase in the histamine concentration of the oxyntic mucosa. Feeding or injection of insulin or pentagastrin lowered the histamine concentration. As judged by electron microscopy, the proliferation of endocrine-like cells induced by porta-caval shunting was restricted to the ECL cell type. Besides occurring in greater number, these cells were larger than those in unoperated controls, and their cytoplasm was densely packed with granules that were increased in size. 5. Following antrectomy of the porta-caval shunted rats the number of enterochromaffin-like cells and the oxyntic histamine concentration was reduced. 6. The results support the idea that gastrin exerts trophic as well as excitatory effects on oxyntic endocrine-like cells.

Animals↗
PubMed1976

Effect of bilateral nephrectomy on serum gastrin concentration, gastric histamine content, histidine decarboxylase activity, and acid secretion in the rat.

Nephrectomy caused a marked increase in the concentration of circulating gastrin immunoreactivity but did not increase basal acid secretion. In normal rats, both histamine and pentagastrin stimulated gastric acid output, but after nephrectomy only histamine was effective. Histidine decarboxylase in the oxyntic mucosa was greatly activated following nephrectomy. Thus, in the nephrectomized rat gastrin (and pentagastrin) no longer evoked acid secretion, whereas it retained its ability to activate gastric histidine decarboxylase. The results suggest that the kidney is important for metabolism and excretion not only of gastrin but of humoral antagonists of gastrin-induced acid secretion as well.

Animals↗
PubMed1976

Occurrence of human pancreatic polypeptide in pancreatic endocrine tumors. Possible implication in the watery diarrhea syndrome.

Eighteen endocrine pancreatic tumors were examined for the occurrence of cells producing insulin, glucagon, gastrin, human pancreatic polypeptide (HPP), and vasoactive intestinal polypeptide (VIP) and for A1 cells. More than half of the tumors were mixed, i.e., they contained more than one type of hormone-producing cell. The clinical symptoms were attributable only to one of the hormones produced by the mixed tumors. Three of four tumors causing the watery diarrhea syndrome contained both VIP and HPP cells. In one such tumor there was a strong predominance of HPP cells; the serum HPP levels of this patient were a thousandfold elevated, whereas her VIP levels were within the normal range. Several lines of evidence point to HPP as a possible agent causing the watery diarrhea syndrome. In many of our patients, HPP cells hyperplasia was present in the extratumoral pancreas. Such hyperplasia may give rise to the raised serum HPP levels seen in many patients having endocrine pancreatic tumors.

Diarrhea↗