Ethnic differences in insulin sensitivity, β-cell function, and hepatic extraction between Japanese and Caucasians: a minimal model analysis.

Context: Ethnic differences have previously been reported for type 2 diabetes.

Objective: We aimed at assessing the potential differences between Caucasian and Japanese subjects ranging from normal glucose tolerance (NGT) to impaired glucose tolerance (IGT) and to type 2 diabetes.

Design: This was a cross-sectional study with oral glucose tolerance tests to assess β-cell function, hepatic insulin extraction, and insulin sensitivity.

Body composition is the main determinant for the difference in type 2 diabetes pathophysiology between Japanese and Caucasians.

OBJECTIVE This cross-sectional clinical study compared the pathophysiology of type 2 diabetes in Japanese and Caucasians and investigated the role of demographic, genetic, and lifestyle-related risk factors for insulin resistance and β-cell response. RESEARCH DESIGN AND METHODS A total of 120 Japanese and 150 Caucasians were enrolled to obtain comparable distributions of high/low BMI values across glucose tolerance states (normal glucose tolerance, impaired glucose tolerance, and type 2 diabetes), which were assessed by oral glucose tolerance tests. BMI in the two cohorts was distributed around the two regional cutoff values for obesity.

Albumin-bound basal insulin analogues (insulin detemir and NN344): comparable time-action profiles but less variability than insulin glargine in type 2 diabetes.

Aim: This study compared the time-action profiles of the novel albumin-bound basal insulin analogue NN344 with those of insulin detemir and insulin glargine in individuals with type 2 diabetes.

Methods: Twenty-seven insulin-treated men with type 2 diabetes [body mass index 30.8 +/- 2.

Adenosine A 2B receptors modulate cAMP levels and induce CREB but not ERK1/2 and p38 phosphorylation in rat skeletal muscle cells.

The present study examined the existence of the adenosine A(1),A(2A), and A(2B) receptors and the effect of receptor activation on cAMP accumulation and protein phosphorylation in primary rat skeletal muscle cells. Presence of mRNA and protein for all three receptors was demonstrated in both cultured and adult rat skeletal muscle. NECA (10(-9)-10(-4)M) increased the cAMP concentration in cultured muscle cells with an EC(50) of (95% confidence interval)=15 (5.

Extracellular formation and uptake of adenosine during skeletal muscle contraction in the rat: role of adenosine transporters.

1. The existence of adenosine transporters in plasma membrane giant vesicles from rat skeletal muscles and in primary skeletal muscle cell cultures was investigated. In addition, the contribution of intracellularly or extracellularly formed adenosine to the overall extracellular adenosine concentration during muscle contraction was determined in primary skeletal muscle cell cultures.

Distribution of adenosine A1, A2A and A2B receptors in human skeletal muscle.

Many important physiological functions of skeletal muscle, such as glucose uptake, contraction and blood flow, have been proposed to be regulated via the action of adenosine on adenosine receptors. The cellular location of adenosine receptors in skeletal muscle is however, not known. The present study examined the distribution of A1, A2A and A2B adenosine receptors in human skeletal muscle using immunohistochemistry.

Differential regulation of MAP kinase by contraction and insulin in skeletal muscle: metabolic implications.

We have investigated the activation of the extracellular signal-regulated kinases (ERK1 and ERK2) by muscle contraction and insulin in perfused rat skeletal muscle. Both stimuli activated ERK1 and ERK2 by an upstream kinase MAP/ERK kinase (MEK)-dependent mechanism, as the MEK inhibitor PD-98059 inhibited ERK phosphorylation. The presence of the phosphatidylinositol (PI) 3-kinase inhibitors LY-294002 and wortmannin totally eradicated ERK1 and ERK2 phosphorylation in response to insulin but not contraction.