Obesity is the main determinant of insulin resistance more than the circulating pro-inflammatory cytokines levels in rheumatoid arthritis patients.

Background: Systemic blockade of TNF-α in Rheumatoid arthritis with insulin resistance seems to produce more improvement in insulin sensitivity in normal weight patients with Rheumatoid arthritis than in obese patients with Rheumatoid arthritis, suggesting that systemic-inflammation and obesity are independent risk factors for insulin resistance in Rheumatoid arthritis patients.

Objectives: To evaluate the insulin resistance in: normal weight patients with Rheumatoid arthritis, overweight patients with Rheumatoid arthritis, obese Rheumatoid arthritis patients, and matched control subjects with normal weight and obesity; and its association with major cytokines involved in the pathogenesis of the disease.

Methods: Assessments included: body mass index, insulin resistance by Homeostasis Model Assessment, ELISA method, and enzymatic colorimetric assay.

Receptor-independent effects of 2'(3')-O-(4-benzoylbenzoyl)ATP triethylammonium salt on cytosolic pH.

The effect of the relatively potent P2X7 receptor agonist 2'(3')-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate triethylammonium salt (BzATP-TEA) on cytosolic pH (pHi) was studied using MC3T3-E1 osteoblast-like cells, which endogenously express P2X7 receptors. pHi was measured fluorimetrically using the pH-sensitive dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein. BzATP-TEA (0.

Characterization of an outward rectifying chloride current of Xenopus tropicalis oocytes.

Here, we describe an outward rectifying current in Xenopus tropicalis oocytes that we have called xtClC-or. The current has two components; the major component is voltage activated and independent of intracellular or extracellular Ca(2+), whereas the second is a smaller component that is Ca(2+) dependent. The properties of the Ca(2+)-independent current, such as voltage dependence and outward rectification, resemble those of ClC anion channels/transporters.

Functional interactions between P2X4 and P2X7 receptors from mouse salivary epithelia.

Mouse parotid acinar cells express P2X4 and P2X7 receptors (mP2X4R and mP2X7R) whose physiological function remains undetermined. Here we show that mP2X4R expressed in HEK-293 cells do not allow the passage of tetraethylammonium (TEA+) and promote little, if any, ethidium bromide (EtBr) uptake when stimulated with ATP or BzATP. In contrast, mP2X7R generates slowly decaying TEA+ current, sustained Na+ current and promotes robust EtBr uptake.

Na+ modulates anion permeation and block of P2X7 receptors from mouse parotid glands.

We previously reported that mouse parotid acinar cells display anion conductance (I(ATPCl)) when stimulated by external ATP in Na+-free extracellular solutions. It has been suggested that the P2X7 receptor channel (P2X7R) might underlie I(ATPCl). In this work we show that I (ATPCl) can be activated by ATP, ADP, AMP-PNP, ATPgammaS and CTP.