The effects of tolbutamide and glibenclamide on the metabolism of cyclic AMP were investigated in pancreatic islets of the rat. Changes in cyclic AMP were assessed by measuring [3H]cyclic AMP after labeling of the islets with [2-3H]adenine. In the presence of a nonstimulatory concentration of glucose (3.3 mM), both sulfonylureas caused a rapid increase in islet [3H]cyclic AMP, which declined within 5 (tolbutamide) or 10 min (glibenclamide). In the absence of glucose, the glibenclamide effect was shortened, but the initial (1 min) response of [3H]-cyclic AMP was unaffected. Glucose could be substituted with d-glyceraldehyde but not pyruvate for prolongation of the glibenclamide response. The effect of glucose withdrawal on the glibenclamide response was reproduced by the addition of d-mannoheptulose to glucose containing media.
V. Grill, E. Cerasi
Usage data is cumulative from April 2023 through April 2024.
Usage | JCI | PMC |
---|---|---|
Text version | 69 | 0 |
31 | 18 | |
Scanned page | 105 | 1 |
Citation downloads | 7 | 0 |
Totals | 212 | 19 |
Total Views | 231 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.