Related Experiment Video
Updated: Aug 13, 2026

A Method for Mouse Pancreatic Islet Isolation and Intracellular cAMP Determination
Published on: June 25, 2014
CART regulates islet hormone secretion and is expressed in the beta-cells of type 2 diabetic rats
Nils Wierup1, Maria Björkqvist, Michael J Kuhar
1Department of Experimental Medical Science, Division of Diabetes, Metabolism, and Endocrinology, Lund University, Sweden. nils.wierup@med.lu.se
Abstract:
Cocaine- and amphetamine-regulated transcript (CART) is an anorexigenic peptide widely expressed in the central, peripheral, and enteric nervous systems. CART is also expressed in endocrine cells, including beta-cells during rat development and delta-cells of adult rats. We examined the effect of CART 55-102 on islet hormone secretion, using INS-1(832/13) cells and isolated rat islets. In addition, islet CART expression was examined in two rat models of type 2 diabetes: Goto-Kakizaki (GK) rats and dexamethasone (DEX)-treated rats. At high glucose, CART potentiated cAMP-enhanced insulin secretion via the cAMP/protein kinase A-dependent pathway. In the absence of cAMP-elevating agents, CART was without effect on INS-1 cells but modestly inhibited secretion of insulin, glucagon, and somatostatin from isolated islets. CART was markedly upregulated in the beta-cells of both diabetes models. Thus, in DEX-treated rats, islet CART mRNA expression, and the number of CART-immunoreactive beta-cells were 10-fold higher than in control rats. In GK rats, the relative number of CART-expressing beta-cells was 30-fold higher than in control rats. We conclude that CART is a regulator of islet hormone secretion and that CART is upregulated in the beta-cells of type 2 diabetic rats.
Related Concept Videos
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
Insulin and C-peptide are co-secreted in...
Hormones Regulating Blood Glucose
In addition to accelerating glucose uptake and utilization, insulin has...
Cell Specific Gene Expression
Cells and Secretions of the Pancreas
Exocrine function is carried out by acinar cells, organized into clusters known as acini. These cells contribute to digestion by releasing substantial quantities of enzyme-rich, alkaline digestive juices.
Concurrently, the dispersed clusters of endocrine cells throughout the...
Insulin: The Receptor and Signaling Pathways
Insulin Secretory Vesicles

