Phosphatidylinositol-4, 5-bisphosphate [PI(4,5)P(2)] has been implicated in the priming of large dense-core vesicles in many secretory cells; however, its role in the Ca(2+)-dependent secretory activity in pituitary cells remains elusive. We suggest that PI(4,5)P(2) increases the size of the readily releasable vesicle pool by regulating the effectiveness of vesicular mobilization and fusion in an ATP-dependent manner.
COBISS.SI-ID: 19161387
The aim of this study was to define when an insulin-positive cell becomes functional in vivo and starts to exocytose insulin in a regulated nutrient-dependent manner. Despite the apparent stability of the transcription factor profile reported in insulin-positive cells during late-embryonic life, functional beta cells appear only 2 days after birth.
COBISS.SI-ID: 19161376
Beta-cells in pancreatic islets form complex syncytia. Sufficient cell-to-cell electrical coupling seems to ensure coordinated depolarization pattern and insuPancreas slice is a novel method of choice to study the physiology of beta-cells still embedded in their normal cellulo-social context. I present major advantages, list drawbacks and provide an overview on recent advances in our understanding of the physiology of beta-cells using the pancreas slice approach.
COBISS.SI-ID: 62051585
The Goto Kakizaki (GK) rat is a widely used animal model to study defective glucose-stimulated insulin release in type-2 diabetes (T2D). As in T2D patients, the expression of several proteins involved in Ca(2+)-dependent exocytosis of insulin-containing large dense-core vesicles is dysregulated in this model. We conclude that a decrease in the sensitivity of the GK rat beta-cell to depolarization-evoked Ca(2+) influx is involved in defective glucose-stimulated insulin secretion.
COBISS.SI-ID: 58839809
We studied the effect of gap junctional coupling on the excitability of beta-cells in slices of pancreas, which provide a normal environment for islet cells. Our data indicate an important role for Cx36-gap junctions in modulating stimulation threshold and kinetics of insulin release.
COBISS.SI-ID: 58790401