Norio Harada

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OBJECTIVE The therapeutic potential of exendin-4, an agonist of the glucagon-like peptide-1 receptor (GLP-1R), on diabetic polyneuropathy (DPN) in streptozotocin (STZ)-induced diabetic mice was investigated. RESEARCH DESIGN AND METHODS The presence of the GLP-1R in lumbar dorsal root ganglion (DRG) was evaluated by immunohistochemical analyses. DRG(More)
Calcium plays a fundamental role as second messenger in intracellular signaling and bone serves as the body's calcium reserve to tightly maintain blood calcium levels. Calcium in ingested meal is the main supply and inadequate calcium intake causes osteoporosis and bone fracture. Here, we describe a novel mechanism of how ingested calcium is deposited on(More)
AIMS Hypersecretion of glucagon and reduced insulin secretion both contribute to hyperglycemia in type 2 diabetes (T2DM). However, the relative contributions of impaired glucagon and insulin secretions in glucose excursions at the various stages of T2DM development remain to be determined. METHODS The responses of glucagon and insulin as well as those of(More)
Gastric inhibitory polypeptide (GIP) is an incretin secreted from enteroendocrine K cells in response to meal ingestion. Recently free fatty acid receptor G protein-coupled receptor (GPR) 120 was identified as a lipid sensor involved in glucagon-like peptide-1 secretion. However, Gpr 120 gene expression and its role in K cells remain unclear, partly due to(More)
Glucose is essential for energy production in the living body; the glucose transporter plays a critical role in various organs. Glucose transporters are classified into two families: facilitative glucose transporters (GLUTs) and sodium-dependent glucose transporters (SGLTs), through which glucose is transported by facilitated diffusion, and Na/glucose are(More)
GIP and GLP-1 are major incretins and secreted from K-cell and L-cell in response to meal ingestion, respectively. GIP and GLP-1 potentiate glucose-induced insulin secretion by binding GIP receptor and GLP-1 receptor, respectively, on pancreatic beta-cell and increasing intracellular cAMP concentration (incretin effect). GIP receptor and GLP-1 receptor are(More)
Gastric inhibitory polypeptide (GIP) is an incretin released from enteroendocrine K-cells in response to nutrient ingestion. GIP potentiates glucose-stimulated insulin secretion and induces energy accumulation into adipose tissue, resulting in obesity. Plasma GIP levels are reported to be increased in the obese state. However, the molecular mechanisms of(More)
AIM Glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) are major incretins associated with body weight regulation. Dipeptidyl peptidase-IV (DPP-IV) inhibitor increases plasma active GLP-1 and GIP. However, the magnitude of the effects of enhanced GLP-1 and GIP signaling by long-term DPP-IV inhibition on body weight and insulin(More)
Gastric inhibitory polypeptide (GIP) is an incretin released from enteroendocrine K cells in response to nutrient intake, especially fat. GIP is one of the contributing factors inducing fat accumulation that results in obesity. A recent study shows that fatty acid-binding protein 5 (FABP5) is expressed in murine K cells and is involved in fat-induced GIP(More)
OBJECTIVE The management of diabetes mellitus includes controlling the blood glucose level, body weight, blood pressure and serum lipid level. The coexistence of diabetes and a high low-density lipoprotein cholesterol (LDL-C) level promotes atherosclerosis of the coronary arteries and increases the risk of coronary artery disease (CAD). We compared the(More)