Direct long-term effect of hydrocortisone on insulin and glucagon release from mouse pancreatic islets in tissue culture

Brunstedt, Janne; Jh, Nielsen

doi:10.1530/acta.0.0960498

Cited by 36 publications

(23 citation statements)

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“…3) may indicate a limited capacity to synthesize TRH-IR or lack of supporting factors in the culture medium. This may be analogous to the supporting effect of hydrocortisone (21) and growth hormone (22) on the insulin production from cultured islets. The difficulties in demonstrating TRH biosynthesis in isolated tissues (23) may be due to general impairment of the enzymatic conversion of peptide precursors at the carboxy-terminal of amidated forms (24,25).…”

Section: Discussionmentioning

confidence: 77%

Biosynthesis and release of thyrotropin-releasing hormone immunoreactivity in rat pancreatic islets in organ culture. Effects of age, glucose, and streptozotocin.

Dolva¹,

Nielsen²,

Welinder³

et al. 1983

J. Clin. Invest.

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A B S T R A C T Thyrotropin-releasing hormone immunoreactivity (TRH-IR) was measured in isolated islets and in medium from rat pancreatic islets maintained in organ culture. TRH-IR in methanol extracts of both islets and culture medium was eluted in the same position as synthetic TRH by ion-exchange and gel chromatography and exhibited dilution curves parallel with synthetic TRH in radioimmunoassay.[3H]Histidine was incorporated into a component that reacted with TRH antiserum and had the same retention time as synthetic TRH on reversed-phase highperformance liquid chromatography.A continuous release of TRH-IR into the culture medium was observed from islets of both 5-d-old (newborn) and 30-d-old (adult) rats with a maximum on the second day of culture (28.7±7.0 and 13.3±3.6 fmol/islet per d, respectively). The content of TRH-IR was higher in freshly isolated islets from newborn rats (22.4±2.3 fmol/islet) than in adult rat islets, which, however, increased their content from 1.3±0.5 to 7.0±0.5 fmol/islet during the first 3 d of culture. Adult rat islets maintained in medium with 20 mM glucose released significantly more TRH-IR than islets in 3.3 mM glucose medium (13.0±0.7 vs. 4.3±0.3 fmol/islet per d). In contrast, the content of TRH-IR in the islets was reversed (1.4±0.3 vs. 4.7±1.6 fmol/ islet). By exposing islets from newborn rats to streptozotocin 0.7 mg/ml for 30 min, a 50% reduction of (3,4), and seems t6 be located mainly in the islets of Langerhans (5,6). The amount of TRH-IR in the rat pancreas and islets is highest during the first 24 h after birth, but declines rapidly with age, concomitantly with the appearance of TRH in the hypothalamus (7,8 METHODSIslet isolation and culture. Pancreatic islets were isolated from 5-d-old Wistar rats (newborn) of both sexes and from overnight-fasted 30-d-old male Wistar rats (adult) (M0lle-gaard, Lille Skensved, Denmark).The excised pancreas was digested by the collagenase method and the islets were isolated after. gradient centrifugation on PercollT (11). Isolated islets were placed in 5-cm plastic petri dishes (Nunc, Roskilde, Denmark). Each dish contained 100 islets in 5 ml medium RPMI 1640 (Flow Laboratories, Irvine, UK) containing 11 mM glucose and 10% heat-inactivated newborn calf serum (NBCS) (Gibco Laboratories, Paisly, UK). The dishes were incubated at 370C in a humidified atmosphere containing 5% carbon dioxide. Medium and islets were withdrawn at various intervals as indicated in the figures. Islets were homogenized in distilled water by sonication. Hormones were measured in both medium and islets.Glucose stimulation. Islets from adult rats were preincubated for 1 d in RPMI 1640 medium containing 10% NBCS and 11 mM glucose and then transferred to RPMI 1640 medium containing 0.5% human serum (HS) and either 3.3 or 20 mM glucose. After 1 d in 3.3 mM glucose one group of islets was transferred to 20 mM glucose, while others were maintained in either 3.3 or 20 mM glucose. The medium was changed daily and hormones were measured in medium and islets.Streptozo...

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Section: Discussionmentioning

confidence: 77%

Biosynthesis and release of thyrotropin-releasing hormone immunoreactivity in rat pancreatic islets in organ culture. Effects of age, glucose, and streptozotocin.

Dolva¹,

Nielsen²,

Welinder³

et al. 1983

J. Clin. Invest.

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“…A rapid (within minutes) inhibition of glucose-induced insulin secretion was produced by 0.1-1 M corticosterone (20,21) or 100 M cortisone (22), and was attributed to an alteration of Ca 2 ϩ fluxes in ␤ cells (23). In contrast, no rapid inhibitory effect was observed in several other studies (12,16,24,25). A slower (within hours or days) inhibitory effect followed treatment of isolated rat or mouse islets with cortisol, prednisolone, or dexamethasone (25)(26)(27).…”

Section: Introductionmentioning

confidence: 91%

Direct glucocorticoid inhibition of insulin secretion. An in vitro study of dexamethasone effects in mouse islets.

Lambillotte¹,

Gilon²,

Henquin³

1997

J. Clin. Invest.

368

308

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The direct effects of glucocorticoids on pancreatic ␤ cell function were studied with normal mouse islets. Dexamethasone inhibited insulin secretion from cultured islets in a concentration-dependent manner: maximum of ‫ف‬ 75% at 250 nM and IC 50 at ‫ف‬ 20 nM dexamethasone. This inhibition was of slow onset (0, 20, and 40% after 1, 2, and 3 h) and only slowly reversible. It was prevented by a blocker of nuclear glucocorticoid receptors, by pertussis toxin, by a phorbol ester, and by dibutyryl cAMP, but was unaffected by an increase in the fuel content of the culture medium. Dexamethasone treatment did not affect islet cAMP levels but slightly reduced inositol phosphate formation. After 18 h of culture with or without 1 M dexamethasone, the islets were perifused and stimulated by a rise in the glucose concentration from 3 to 15 mM. Both phases of insulin secretion were similarly decreased in dexamethasone-treated islets as compared with control islets. This inhibition could not be ascribed to a lowering of insulin stores (higher in dexamethasone-treated islets), to an alteration of glucose metabolism (glucose oxidation and NAD(P)H changes were unaffected), or to a lesser rise of cytoplasmic Ca 2 ϩ in ␤ cells (only the frequency of the oscillations was modified). Dexamethasone also inhibited insulin secretion induced by arginine, tolbutamide, or high K ϩ . In this case also the inhibition was observed despite a normal rise of cytoplasmic Ca 2 ϩ . In conclusion, dexamethasone inhibits insulin secretion through a genomic action in ␤ cells that leads to a decrease in the efficacy of cytoplasmic Ca 2 ϩ on the exocytotic process. ( J. Clin. Invest. 1997. 99:414-423.)

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“…The effects of glucocorticoid on insulin secretion are dependent upon the dose and duration of administration [8]. While most studies report inhibition of insulin secretion by glucocorticoids [5,[9][10][11], long-term culture in hydrocortisone [12] and dexamethasone-treatment of islets from adrenalectomised rats [13] increase insulin release. However, transgenic mice overexpressing GR (also known as NR3C1) specifically in the beta cell have impaired glucose tolerance due to decreased insulin release, suggesting a direct inhibitory action of glucocorticoid upon the beta cell [14].…”

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confidence: 99%

11β-Hydroxysteroid dehydrogenase type 1 regulates insulin and glucagon secretion in pancreatic islets

et al. 2008

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Aims/hypothesis Exposure to excess glucocorticoid is associated with pancreatic beta cell damage and decreased glucose-stimulated insulin secretion (GSIS). Inactive glucocorticoids (cortisone, 11-dehydrocorticosterone) are converted to active cortisol and corticosterone by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which requires NADPH as cofactor, which is generated by hexose-6-phosphate dehydrogenase (H6PDH). We investigated the localisation and activity of 11β-HSD1 within pancreatic islets, and determined its functional role in the regulation of insulin and glucagon secretion. Methods mRNA expression of 11β-HSD1 (also known as HSD11B1), glucocorticoid receptor and H6PDH (also known as H6PD) in human pancreas and murine islets was examined by real-time PCR. 11β-HSD1 protein levels were examined by immunohistochemistry and immunofluorescence. 11β-HSD1 activity was assessed in intact tissue and isolated islets of wild-type (WT) and both 11β-Hsd1-and H6pdh-null mice. Glucagon secretion and insulin secretion were analysed by RIA and ELISA respectively in isolated murine islets incubated with dexamethasone. Results 11β-HSD1 co-localised with glucagon in the periphery of murine and human islets, but not with insulin or somatostatin. Dexamethasone, 11-dehydrocorticosterone and corticosterone induced a dose-dependent decrease in GSIS and glucagon secretion following low glucose stimulation. Reduction of 11β-HSD1 activity with specific inhibitors or in experiments carried out in H6pdh-null mice reversed the effects of 11-dehydrocorticosterone, but had no effect following treatment with corticosterone. Conclusions/interpretation Local regeneration of glucocorticoid via 11β-HSD1 within alpha cells regulates glucagon secretion and in addition may act in a paracrine manner to limit insulin secretion from beta cells.

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Direct long-term effect of hydrocortisone on insulin and glucagon release from mouse pancreatic islets in tissue culture

Cited by 36 publications

References 0 publications

Biosynthesis and release of thyrotropin-releasing hormone immunoreactivity in rat pancreatic islets in organ culture. Effects of age, glucose, and streptozotocin.

Biosynthesis and release of thyrotropin-releasing hormone immunoreactivity in rat pancreatic islets in organ culture. Effects of age, glucose, and streptozotocin.

Direct glucocorticoid inhibition of insulin secretion. An in vitro study of dexamethasone effects in mouse islets.

11β-Hydroxysteroid dehydrogenase type 1 regulates insulin and glucagon secretion in pancreatic islets

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