Monoamines in Pancreatic Islets of Guinea Pig, Hamster, Rat, and Mouse Determined by High Performance Liquid Chromatography

Lundquist, Ingmar; Åhrén, Bo; Hansson, Christer; Håkanson, R.

doi:10.1097/00006676-198912000-00002

Cited by 24 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, what purpose do VMAT2 molecules serve in β cells? Clues to the role of VMAT2 in islet function can be garnered from studies showing that purified islets (with little or no contamination from surrounding nervous tissue) are rich sources of mono-amines such as epinephrine and dopamine [45], as well as from studies demonstrating the presence of biosynthetic apparatus for these neurotransmitters in β cells [46,47]. The role of these neurotransmitters as paracrine agents active in the entrainment of secretory activity in islets is still largely speculative, but it has been shown that these neurotransmitters affect islet cell function [48][49][50][51].…”

Section: Resultsmentioning

confidence: 99%

Visualizing pancreatic β-cell mass with [11C]DTBZ

Simpson

Souza

Witkowski

et al. 2006

Nuclear Medicine and Biology

109

View full text Add to dashboard Cite

Abstractβ-Cell mass (BCM) influences the total amount of insulin secreted, varies by individual and by the degree of insulin resistance, and is affected by physiologic and pathologic conditions. The islets of Langerhans, however, appear to have a reserve capacity of insulin secretion and, overall, assessments of insulin and blood glucose levels remain poor measures of BCM, β-cell function and progression of diabetes. Thus, novel noninvasive determinations of BCM are needed to provide a quantitative endpoint for novel therapies of diabetes, islet regeneration and transplantation. Built on previous gene expression studies, we tested the hypothesis that the targeting of vesicular monoamine transporter 2 (VMAT2), which is expressed by β cells, with [ 11 C]dihydrotetrabenazine ([ 11 C]DTBZ), a radioligand specific for VMAT2, and the use of positron emission tomography (PET) can provide a measure of BCM. In this report, we demonstrate decreased radioligand uptake within the pancreas of Lewis rats with streptozotocininduced diabetes relative to their euglycemic historical controls. These studies suggest that quantitation of VMAT2 expression in β cells with the use of [ 11 C]DTBZ and PET represents a method for noninvasive longitudinal estimates of changes in BCM that may be useful in the study and treatment of diabetes.

show abstract

Section: Resultsmentioning

confidence: 99%

Visualizing pancreatic β-cell mass with [11C]DTBZ

Simpson

Souza

Witkowski

et al. 2006

Nuclear Medicine and Biology

109

View full text Add to dashboard Cite

show abstract

“…At least 2 important questions are underscored but left unanswered by these studies: First, what purpose(s) do VMAT2 molecules serve in β cells? Purified islets (with little or no contamination from surrounding nervous tissue) contain monoamines such as epinephrine and dopamine (42), and at least some of the biosynthetic apparatus for these neurotransmitters can be detected in β cells (43). The role of these neurotransmitters as paracrine agents active in the control of secretory activity in islets is still largely speculative, but it has been shown that these neurotransmitters affect islet cell function (44)(45)(46)(47).…”

Section: Discussionmentioning

confidence: 99%

Longitudinal noninvasive PET-based cell mass estimates in a spontaneous diabetes rat model

Souza¹

2006

Journal of Clinical Investigation

135

View full text Add to dashboard Cite

“…It is well known that the sympathetic nervous system control of insulin secretion is mediated by catecholamines, which inhibit insulin release via the ␣ 2 -ARs (12). The adrenergic nerves associated with islets contain a high concentration of catecholamines (28). Because ␤-cells express ␣ 2 -ARs (29,30) and GCs upregulate ␣ 2 -AR expression and signaling in ␤-cell lines (10), we investigated the possibility that inhibition of insulin secretion in TG mice involves a signaling pathway via the ␣ 2 -AR.…”

Section: Discussionmentioning

confidence: 99%

Aged Transgenic Mice With Increased Glucocorticoid Sensitivity in Pancreatic β-Cells Develop Diabetes

et al. 2004

View full text Add to dashboard Cite

Glucocorticoids are diabetogenic hormones because they decrease glucose uptake, increase hepatic glucose production, and inhibit insulin release. To study the long-term effects of increased glucocorticoid sensitivity in ␤-cells, we studied transgenic mice overexpressing the rat glucocorticoid receptor targeted to the ␤-cells using the rat insulin I promoter. Here we report that these mice developed hyperglycemia both in the fed and the overnight-fasted states at 12-15 months of age. Progression from impaired glucose tolerance, previously observed in the same colony at the age of 3 months, to manifest diabetes was not associated with morphological changes or increased apoptosis in the ␤-cells. Instead, our current results suggest that the development of diabetes is due to augmented inhibition of insulin secretion through ␣ 2 -adrenergic receptors (␣ 2 -ARs). Thus, we found a significantly higher density of ␣ 2 -ARs in the islets of transgenic mice compared with controls, based on binding studies with the ␣ 2 -AR agonist UK 14304. Furthermore, incubation of islets with benextramine, a selective antagonist of the ␣ 2 -AR, restored insulin secretion in response to glucose in isolated islets from transgenic mice, whereas it had no effect on control islets. These results indicate that the chronic enhancement of glucocorticoid signaling in pancreatic ␤-cells results in hyperglycemia and impaired glucose tolerance. This effect may involve signaling pathways that participate in the regulation of insulin secretion via the ␣ 2 -AR. Diabetes 53 (Suppl. 1): S51-S59, 2004

show abstract

Monoamines in Pancreatic Islets of Guinea Pig, Hamster, Rat, and Mouse Determined by High Performance Liquid Chromatography

Cited by 24 publications

References 0 publications

Visualizing pancreatic β-cell mass with [11C]DTBZ

Visualizing pancreatic β-cell mass with [11C]DTBZ

Longitudinal noninvasive PET-based cell mass estimates in a spontaneous diabetes rat model

Aged Transgenic Mice With Increased Glucocorticoid Sensitivity in Pancreatic β-Cells Develop Diabetes

Contact Info

Product

Resources

About