TY - JOUR
T1 - Dopamine synthesis and D3 receptor activation in pancreatic β-cells regulates insulin secretion and intracellular [Ca2+] oscillations
AU - Ustione, Alessandro
AU - Piston, David W.
PY - 2012
Y1 - 2012
N2 - Pancreatic islets are critical for glucose homeostasis via the regulated secretion of insulin and other hormones. We propose a novel mechanism that regulates insulin secretion from β-cells within mouse pancreatic islets: A dopaminergic negative feedback acting on insulin secretion. We show that islets are a site of dopamine synthesis and accumulation outside the central nervous system. We show that both dopamine and its precursor L-dopa inhibit glucose-stimulated insulin secretion, and this inhibition correlates with a reduction in frequency of the intracellular [Ca2+] oscillations. We further show that the effects of dopamine are abolished by a specific antagonist of the dopamine receptor D3. Because the dopamine transporter and dopamine receptors are expressed in the islets, we propose that cosecretion of dopamine with insulin activates receptors on the β-cell surface. D3 receptor activation results in changes in intracellular [Ca2+] dynamics, which, in turn, lead to lowered insulin secretion. Because blocking dopaminergic negative feedback increases insulin secretion, expanding the knowledge of this pathway in β-cells might offer a potential new target for the treatment of type 2 diabetes.
AB - Pancreatic islets are critical for glucose homeostasis via the regulated secretion of insulin and other hormones. We propose a novel mechanism that regulates insulin secretion from β-cells within mouse pancreatic islets: A dopaminergic negative feedback acting on insulin secretion. We show that islets are a site of dopamine synthesis and accumulation outside the central nervous system. We show that both dopamine and its precursor L-dopa inhibit glucose-stimulated insulin secretion, and this inhibition correlates with a reduction in frequency of the intracellular [Ca2+] oscillations. We further show that the effects of dopamine are abolished by a specific antagonist of the dopamine receptor D3. Because the dopamine transporter and dopamine receptors are expressed in the islets, we propose that cosecretion of dopamine with insulin activates receptors on the β-cell surface. D3 receptor activation results in changes in intracellular [Ca2+] dynamics, which, in turn, lead to lowered insulin secretion. Because blocking dopaminergic negative feedback increases insulin secretion, expanding the knowledge of this pathway in β-cells might offer a potential new target for the treatment of type 2 diabetes.
UR - http://www.scopus.com/inward/record.url?scp=84868129185&partnerID=8YFLogxK
U2 - 10.1210/me.2012-1226
DO - 10.1210/me.2012-1226
M3 - Article
C2 - 22918877
AN - SCOPUS:84868129185
SN - 0888-8809
VL - 26
SP - 1928
EP - 1940
JO - Molecular Endocrinology
JF - Molecular Endocrinology
IS - 11
ER -