You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Pancreatic beta-cell response to increased metabolic demand and to pharmacologic secretagogues requires EPAC2A. Incretin hormone action on ß-cells stimulates in parallel two different intracellular cyclic AMP-dependent signaling branches mediated by PKA and EPAC2A. Both pathways contribute towards potentiation of glucose-stimulated insulin secretion (GSIS). However, the overall functional role of EPAC2A in ß-cells as it relates to in vivo glucose homeostasis remains incompletely understood. Therefore, we have examined in vivo GSIS in global EPAC2A knockout mice. Additionally, we have conducted in vitro studies of GSIS and calcium dynamics in isolated EPAC2A-deficient islets. EPAC2A deficiency does not impact glucose-stimulated insulin secretion in mice under basal conditions. However, when mice are exposed to diet-induced insulin resistance, pharmacologic secretagogue stimulation of ß-cells with an incretin hormone glucagon-like peptide-1 analogue or with a Fatty Acid Receptor 1/GPR40 selective activator, EPAC2A is required for the increased ß-cell response to secretory demand. Under these circumstances, EPAC2A is required for potentiating the early dynamic increase in islet calcium levels after glucose stimulation, which is reflected in potentiated first phase insulin secretion. These studies broaden our understanding of EPAC2A function and highlight its significance during increased secretory demand or drive on ß-cells. Our findings advance the rationale for developing EPAC2A selective pharmacologic activators for ß-cell targeted pharmacotherapy in type 2 diabetes mellitus.
{"Chemical": ["calcium", "glucose", "cyclic AMP", "Fatty Acid"]}