The ultrastructure of the human pancreatic islets

Deconinck, Johan; Assche, F.A. Van; Potvliege, P; Gepts, W

doi:10.1007/bf01218493

Cited by 49 publications

(9 citation statements)

References 18 publications

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“…Some of the hypoglycemic treatment fetal ␤-cells, however, did have distended RER, but this did not decrease the size, number, or location of secretory granules present. Our measurement of secretory granule diameter is consistent with previously published values for 1-dayold lambs (31) but is smaller than published diameters for the human fetus (33) or neonate (9). There are no published values for secretory granule number, combined area of all secretory granules, or combined area of all mitochondria for fetal sheep ␤-cells for comparison.…”

Section: Discussionsupporting

confidence: 85%

“…Three or four micrographs with at least one ␤-cell in the image were analyzed for each fetus. ␤-Cells were identified by the characteristic appearance of the secretory granules, which contain contents of variable electron density with a surrounding halo (6,9,31,33). In addition, Ͼ90% of the total islet area contained insulin-positive ␤-cells (see RESULTS), facilitating selection of ␤-cells for analysis.…”

Section: Methodsmentioning

confidence: 99%

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Chronic fetal hypoglycemia inhibits the later steps of stimulus-secretion coupling in pancreatic β-cells

Rozance

Limesand²,

Zerbe

et al. 2007

American Journal of Physiology-Endocrinology and Metabolism

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We measured the impact of chronic late gestation hypoglycemia on pancreatic islet structure and function to determine the cause of decreased insulin secretion in this sheep model of fetal nutrient deprivation. Late gestation hypoglycemia did not decrease pancreas weight, insulin content, beta-cell area, beta-cell mass, or islet size. The pancreatic islet isolation procedure selected a group of islets that were larger and had an increased proportion of beta-cells compared with islets measured in pancreatic sections, but there were no morphologic differences between islets isolated from control and hypoglycemic fetuses. The rates of glucose-stimulated pancreatic islet glucose utilization (126.2 +/- 25.3 pmol glucose.islet(-1).h(-1), hypoglycemic, vs. 93.5 +/- 5.5 pmol glucose.islet(-1).h(-1), control, P = 0.47) and oxidation (10.5 +/- 1.7 pmol glucose.islet(-1).h(-1), hypoglycemic, vs. 10.6 +/- 1.6 pmol glucose.islet(-1).h(-1), control) were not different in hypoglycemic fetuses compared with control fetuses. Chronic late gestation hypoglycemia decreased insulin secretion in isolated pancreatic islets by almost 70% in response to direct nonnutrient membrane depolarization and in response to increased extracellular calcium entry. beta-Cell ultrastructure was abnormal with markedly distended rough endoplasmic reticulum in three of the seven hypoglycemic fetuses studied, but in vitro analysis of hypoglycemic control islets showed no evidence that these changes represented endoplasmic reticulum stress, as measured by transcription of glucose regulatory protein-78 and processing of X-box binding protein-1. In conclusion, these studies show that chronic hypoglycemia in late gestation decreases insulin secretion by inhibiting the later steps of stimulus-secretion coupling after glucose metabolism, membrane depolarization, and calcium entry.

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Section: Discussionsupporting

confidence: 85%

Section: Methodsmentioning

confidence: 99%

Chronic fetal hypoglycemia inhibits the later steps of stimulus-secretion coupling in pancreatic β-cells

Rozance

Limesand²,

Zerbe

et al. 2007

American Journal of Physiology-Endocrinology and Metabolism

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“…It should be noted, however, that the human pancreas contains at least two distinct small-granulated islet cell types -the one containing the smallest granules being the PP cell. Of the islet cell types previously described in the human pancreas the type V cell of Deconinck et al [28] seems to correspond best with the PP cell.…”

Section: Discussionmentioning

confidence: 82%

Pancreatic polypeptide ? A postulated new hormone: Identification of its cellular storage site by light and electron microscopic immunocytochemistry

1976

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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.

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“…Two qualitative studies have demonstrated the presence of somatostatin cells in the human fetus [1,6]. With ultrastructural and histochemical techniques [4,10], it has been shown that the islets of neonates or young infants contain a high proportion of non-insulin and non-glucagon cells, most likely corresponding to somatostatin cells. This has been recently confirmed [15] with an immunofluorescence method.…”

mentioning

confidence: 99%

Abundance of somatostatin cells in the human neonatal pancreas

1980

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Pancreatic somatostatin cells have been studied in human neonates and adults using an immunoperoxidase technique. Their volume density in the head, isthmus, corpus and tail of the gland has been estimated by morphometry. Somatostatin cells were about 20 times more frequent in the neonate (5% of all pancreatic cells) than in the adult (0.23%). Their distribution between the different zones of the pancreas showed few differences except for the lobe of the head rich in PP cells, where the volume density of somatostatin cells was 40% lower.

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The ultrastructure of the human pancreatic islets

Cited by 49 publications

References 18 publications

Chronic fetal hypoglycemia inhibits the later steps of stimulus-secretion coupling in pancreatic β-cells

Chronic fetal hypoglycemia inhibits the later steps of stimulus-secretion coupling in pancreatic β-cells

Pancreatic polypeptide ? A postulated new hormone: Identification of its cellular storage site by light and electron microscopic immunocytochemistry

Abundance of somatostatin cells in the human neonatal pancreas

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