Dose-related effects of calcium to enhance the effects of L-tryptophan on gut hormones and energy intake in obesity.

Context: In males of normal weight, intraduodenal administration of calcium enhances the effects of the amino acid, L-tryptophan (Trp), to suppress energy intake, associated with greater stimulation of cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1) and peptide tyrosine-tyrosine (PYY) secretion (key mechanisms underlying the regulation of pyloric motility and gastric emptying), but not gastrin or glucose-dependent insulinotropic polypeptide (GIP).

Objective: Given the implications for the management of obesity, the current study evaluated the effects of calcium, when administered alone and in combination with Trp, on gut hormone secretion, antropyloroduodenal motility and energy intake in males with obesity.

Methods: Fifteen males with obesity and without type 2 diabetes (mean±SD; age: 27±8 years; body mass index: 30±2 kg/m2; HbA1c: 5.

Intraduodenal calcium enhances the effects of L-tryptophan to stimulate gut hormone secretion and suppress energy intake in healthy males: a randomized, crossover, clinical trial.

Background: In humans, intraduodenal infusion of L-tryptophan (Trp) increases plasma concentrations of gastrointestinal hormones and stimulates pyloric pressures, both key determinants of gastric emptying and associated with potent suppression of energy intake. The stimulation of gastrointestinal hormones by Trp has been shown, in preclinical studies, to be enhanced by extracellular calcium and mediated in part by the calcium-sensing receptor.

Objectives: This study aim was to determine whether intraduodenal calcium can enhance the effects of Trp to stimulate gastrointestinal hormones and pyloric pressures and, if so, whether it is associated with greater suppression of energy intake, in healthy males.

Glucagon-like peptide-1 increases heart rate by a direct action on the sinus node.

Aims: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly used to treat type 2 diabetes and obesity. Albeit cardiovascular outcomes generally improve, treatment with GLP-1 RAs is associated with increased heart rate, the mechanism of which is unclear.

Methods And Results: We employed a large animal model, the female landrace pig, and used multiple in vivo and ex vivo approaches including pharmacological challenges, electrophysiology, and high-resolution mass spectrometry to explore how GLP-1 elicits an increase in heart rate.

A randomized, double-blind, crossover study of the effect of the fluoroquinolone moxifloxacin on glucose levels and insulin sensitivity in young men and women.

Aim: The voltage-gated potassium channel K 11.1 is important for repolarizing the membrane potential in excitable cells such as myocytes, pancreatic α- and β-cells. Moxifloxacin blocks the K 11.