Aims/hypothesis Glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are secreted from enteroendocrine L cells in response to numerous stimuli, including bile salts. Both have multiple effects that are potentially useful in treating diabetes and obesity. L cell number and hormone content in the intestine are highest in the rectum in humans. We investigated the effects of intrarectal sodium taurocholate on plasma GLP-1, PYY, insulin and glucose concentrations, and on food intake of a subsequent meal.Methods Ten obese type 2 diabetic volunteers were each studied on five separate occasions after an overnight fast and oral administration of 100 mg sitagliptin 10 h before the study. They then received an intrarectal infusion of either one of four doses of taurocholate (0.66, 2, 6.66 or 20 mmol, each in 20 ml of vehicle) or vehicle alone (1% carboxymethyl cellulose) single-blind over 1 min. Hormone and glucose measurements were made prior to, and for 1 h following, the infusion. The consumption of a previously selected favourite meal eaten to satiety was measured 75 min after the infusion. Results Taurocholate dose-dependently increased GLP-1, PYY and insulin, with 20 mmol doses resulting in peak concentrations 7.2-, 4.2-and 2.6-fold higher, respectively, than those achieved with placebo (p<0.0001 for each). Plasma glucose decreased by up to 3.8 mmol/l (p<0.001). Energy intake was decreased dose-dependently by up to 47% (p<0.0001). The ED 50 values for effects on integrated GLP-1, insulin, PYY, food intake and glucose-lowering responses were 8. 1, 10.5, 18.5, 24.2

The association between type 2 diabetes and obesity is very strong, and cardiovascular complications are the major cause of morbidity and mortality in diabetic patients. The aim of this study was to investigate early changes in the pattern of genes encoding cardiac muscle regulatory proteins and associated changes in ventricular myocyte contraction and Ca 2+ transport in young (9-to 13-week-old) type 2 Zucker diabetic fatty (ZDF) rats. The amplitude of myocyte shortening was unaltered; however, time-to-peak shortening and time to half-relaxation of shortening were prolonged in ZDF myocytes (163 ± 5 and 127 ± 7 ms, respectively) compared with age-matched control rats (136 ± 5 and 103 ± 4 ms, respectively). The amplitude of the Ca 2+ transient was unaltered; however, time-to-peak Ca 2+ transient was prolonged in ZDF myocytes (66.9 ± 2.6 ms) compared with control myocytes (57.6 ± 2.3 ms). The L-type Ca 2+ current was reduced, and inactivation was prolonged over a range of test potentials in ZDF myocytes. At 0 mV, the density of L-type Ca 2+ current was 1.19 ± 0.28 pA pF −1 in ZDF myocytes compared with 2.42 ± 0.40 pA pF −1 in control myocytes. Sarcoplasmic reticulum Ca 2+ content, release and uptake and myofilament sensitivity to Ca 2+ were unaltered in ZDF myocytes compared with control myocytes. Expression of genes encoding various L-type Ca 2+ channel proteins (Cacna1c, Cacna1g , Cacna1h and Cacna2d1) and cardiac muscle proteins (Myh7) were upregulated, and genes encoding intracellular Ca 2+ transport regulatory proteins (Atp2a2 and Calm1) and some cardiac muscle proteins (Myh6, Myl2, Actc1, Tnni3, Tnn2, and Tnnc1) were downregulated in ZDF heart compared with control heart. A change in the expression of genes encoding myosin heavy chain and L-type Ca 2+ channel proteins might partly underlie alterations in the time course of contraction and Ca 2+ transients in ventricular myocytes from ZDF rats. There has been a spectacular rise in the global prevalence of type 2 diabetes mellitus, and the number of cases of diabetes mellitus has reached pandemic proportions and will continue to escalate. The association between type 2 diabetes and obesity is very strong, and cardiovascular disease is the major cause of morbidity and mortality in diabetic patients (Julien, 1997;Zimmet & Alberti, 2006). Clinical and preclinical studies using Doppler imaging, echocardiography, radionuclide angiography and other techniques have demonstrated a variety of diastolic and systolic dysfunctions in type 2 diabetic patients. These haemodynamic abnormalities include reduced left ventricular ejection fraction, impaired myocardial velocity at early diastole, abnormal relaxation during the early filling phase, prolonged isovolumetric relaxation, lower peak systolic and early diastolic velocity, impaired diastolic relaxation and filling and reduced peak filling rate, with the severity of the abnormalities depending on the patients'

Although repetitive Transcranial Magnetic Stimulation (rTMS) in treatment of stroke in humans has been explored over the past decade the data remain controversial in terms of optimal stimulation parameters and the mechanisms of rTMS long-term effects. This study aimed to explore the potential of different rTMS protocols to induce changes in gene expression in rat cortices after acute ischemic-reperfusion brain injury. The stroke was induced by middle cerebral artery occlusion (MCAO) with subsequent reperfusion. Changes in the expression of 96 genes were examined using low-density expression arrays after MCAO alone and after MCAO combined with 1Hz, 5Hz, continuous (cTBS) and intermittent (iTBS) theta-burst rTMS. rTMS over the lesioned hemisphere was given for two weeks (with a 2-day pause) in a single daily session and a total of 2400 pulses. MCAO alone induced significant upregulation in the expression of 44 genes and downregulation in 10. Two weeks of iTBS induced significant increase in the expression of 52 genes. There were no downregulated genes. 1Hz and 5Hz had no significant effects on gene expression, while cTBS effects were negligible. Upregulated genes included those involved in angiogenesis, inflammation, injury response and cellular repair, structural remodeling, neuroprotection, neurotransmission and neuronal plasticity. The results show that long-term rTMS in acute ischemic-reperfusion brain injury induces complex changes in gene expression that span multiple pathways, which generally promote the recovery. They also demonstrate that induced changes primarily depend on the rTMS frequency (1Hz and 5Hz vs. iTBS) and pattern (cTBS vs. iTBS). The results further underlines the premise that one of the benefits of rTMS application in stroke may be to prime the brain, enhancing its potential to cope with the injury and to rewire. This could further augment its potential to favorably respond to rehabilitation, and to restore some of the loss functions.

Although, several novel forms of intervention aiming at newly identified therapeutic targets are currently being developed for diabetes mellitus (DM), it is well established that physical exercise continues to be one of the most valuable forms of non-pharmacological therapy. The aim of the study was to investigate the effects of exercise training on excitation-contraction coupling and related gene expression in the Goto-Kakizaki (GK) type 2 diabetic rat heart and whether exercise is able to reverse diabetes-induced changes in excitation-contraction coupling and gene expression. Experiments were performed in GK and control rats aged 10-11 months following 2-3 months of treadmill exercise training. Shortening, [Ca(2+)]i and L-type Ca(2+) current were measured in ventricular myocytes with video edge detection, fluorescence photometry and whole cell patch clamp techniques, respectively. Expression of mRNA was assessed in ventricular muscle with real-time RT-PCR. Amplitude of shortening, Ca(2+) transients and L-type Ca(2+) current were not significantly altered in ventricular myocytes from GK sedentary compared to control sedentary rats or by exercise training. Expression of mRNA encoding Tpm2, Gja4, Atp1b1, Cacna1g, Cacnb2, Hcn2, Kcna3 and Kcne1 were up-regulated and Gja1, Kcnj2 and Kcnk3 were down-regulated in hearts of sedentary GK rats compared to sedentary controls. Gja1, Cav3 and Kcnk3 were up-regulated and Hcn2 was down-regulated in hearts of exercise trained GK compared to sedentary GK controls. Ventricular myocyte shortening and Ca(2+) transport were generally well preserved despite alterations in the profile of expression of mRNA encoding a variety of cardiac muscle proteins in the adult exercise trained GK diabetic rat heart.

No abstract