Glucose

Studies were conducted to determine whether maternal substrate utilization during pregnancy affects fetal growth and predisposes offspring to metabolic disease. Female wild-type (WT) and glucose transporter 4 heterozygous mice (G4+/-, a model of altered peripheral substrate utilization) were fed high-fat diet (HFD, 35.5% fat) or control chow (C, 9.5% fat) for 2 wk before mating, throughout pregnancy and lactation (IU/L). WT HFD females exhibited increased serum nonesterified fatty acid and lactate levels and increased hepatic mRNA expression of peroxisome proliferator-activated receptor gamma coactivator-1-beta and SREBP-1c, consistent with increased lipogenesis. G4+/- HFD females exhibited enhanced lipid clearance, and exposure to HFD did not increase hepatic gene expression. HFD independent of maternal genotype decreased fetal growth and birth weight. WT offspring were weaned onto a low-fat diet (5.6% fat). Male offspring of WT mothers exposed to HFD exhibited "catch-up"...

Phospholipid fatty acid (PLFA) analysis of a soil microbial community was coupled with 13C isotope tracer analysis to measure the community’s response to addition of 35 μg of [13C]toluene ml of soil solution−1. After 119 h of incubation with toluene, 96% of the incorporated 13C was detected in only 16 of the total 59 PLFAs (27%) extracted from the soil. Of the total 13C-enriched PLFAs, 85% were identical to the PLFAs contained in a toluene-metabolizing bacterium isolated from the same soil. In contrast, the majority of the soil PLFAs (91%) became labeled when the same soil was incubated with [13C]glucose. Our study showed that coupling 13C tracer analysis with PLFA analysis is an effective technique for distinguishing a specific microbial population involved in metabolism of a labeled substrate in complex environments such as soil.

Endothelin-1 (ET-1), a potent endothelium-derived vasoconstrictor peptide, is secreted in response to insulin. Elevated circulating ET-1 levels have been found in patients with diabetes mellitus and vascular dysfunction. The question arises whether ET-1 acts as a direct modulator of insulin secretion. To test this, we studied the effects of ET-1 on isolated mouse islets of Langerhans. ET-1 (1 nmol/l-1 Μmol/l) dose-dependently stimulated insulin secretion from islets incubated in the presence of 16.7 mmol/l glucose (p<0.05). The effect of ET-1 is glucose-dependent since no potentiation was found at 3.3 mmol/l glucose. Furthermore, ET-1 induced a large, transient increase in glucose-stimulated insulin secretion during islet perifusion in the presence (p<0.001), but not in the absence, of extracellular Ca2+. The rate of 45Ca2+-efflux from 45Ca2+-prelabelled islets was transiently stimulated by ET-1 during perifusion at 16.7 mmol/l glucose in the presence of extracellular Ca2+ (p<0.001). A short-lived increase in 45Ca2+-efflux was also observed in the absence of extracellular Ca2+ (p<0.05). It is suggested that the effects of ET-1 on insulin secretion are critically dependent on influx via Ca2+-channels. In addition, ET-1 transiently enhanced 86Rb+-efflux from 86Rb+-prelabelled islets both in the presence (p<0.001) and in the absence (p<0.001) of extracellular Ca2+ suggesting that ET-1 does not elicit insulin secretion by inhibition of the potassium permeability. Our study provides evidence that ET-1 stimulates insulin secretion via a direct effect on the islets of Langerhans.

Background Remaining edema-free is a challenge for many automated peritoneal dialysis (APD) patients, especially those with fast (“high”) transport characteristics. Although increased use of peritoneal dialysis (PD) solutions with high glucose concentrations may improve volume control, frequent use of such solutions is undesirable. Methods We used the 3-pore kinetic model to evaluate 4 alternative therapy prescriptions for the APD day exchange in anuric patients with high, high-average, and low-average transport characteristics. Four prescriptions were modeled: Therapy 1: Optimal, individualized dwell times with a dry period Therapy 2: Use of a midday exchange Therapy 3: Use of an icodextrin-containing dialysate during a 14-hour dwell Therapy 4: Use of optimal, individualized dwell times, followed by an icodextrin dwell to complete the daytime period The alternative therapies were compared with a reference standard therapy using glucose solution during a 14-hour dwell. The nighttime...

FDG-PET ([18F]fluorodeoxyglucose positron emission tomography) is frequently used to improve the differential diagnosis of dementia. However, a fundamental methodological issue of the reference area for the intensity normalization procedure is still unsolved. Here, we systematically compared the two most commonly used normalization methods to the cerebral and to the cerebellar metabolic rate for glucose with regard to detection and differentiation of dementia syndromes. FDG-PET imaging was performed on 19 subjects with early Alzheimer&#x27;s disease, 13 subjects with early frontotemporal lobar degeneration and 10 subjects complaining of memory impairment, which had not been confirmed by comprehensive clinical testing. Images were normalized to either the cerebral or the cerebellar metabolic rate for glucose. Differences in relative regional glucose metabolism were assessed by voxelwise comparison. Analysis using the two normalization procedures revealed remarkable differential effec...

This article compares the findings of three studies that explored the role of increased blood glucose in improving memory function for subjects who ate breakfast. An initial improvement in memory function for these subjects was found to correlate with blood glucose concentrations. In subsequent studies, morning fasting was found to adversely affect the ability to recall a word list and a story read aloud, as well as recall items while counting backwards. Failure to eat breakfast did not affect performance on an intelligence test. It was concluded that breakfast consumption preferentially influences tasks requiring aspects of memory. In the case of both word list recall and memory while counting backwards, the decline in performance associated with not eating breakfast was reversed by the consumption of a glucose-supplemented drink. Although a morning fast also affected the ability to recall a story read aloud, the glucose drink did not reverse this decline. It appears that breakfast...

Vanadate, an inhibitor of tyrosine phosphatases, has insulin-mimetic properties. It has been shown that acute vanadate administration enhances glucose uptake independently of phosphatidylinositol (PI) 3-kinase and p38 MAPK. However, therapeutic vanadate use requires chronic administration, and this could potentially involve a different signaling pathway(s). Thus, we examined the mechanisms by which chronic vanadate exposure (16 h) stimulates glucose uptake in primary cultures of adult cardiomyocytes. The effect of vanadate on the activation of insulin-signaling molecules was evaluated 60 min after its withdrawal and in the absence of insulin. We therefore evaluated the persistent effect of vanadate on the insulin-signaling cascade. Our results demonstrate that preincubation with low vanadate concentrations (25-75 microM) induces a dose-dependent increase in glucose uptake. The augmentation of this process was not due to alterations in GLUT1 or GLUT4 protein levels, transcription, or...

Elevated glucose levels in the presence of insulin are indicative of type 2 diabetes and the more inclusive metabolic syndrome. Alleles conferring susceptibility to these and other common conditions may be adaptations to past environments. It is possible that other mammals exhibiting environmental diversity harbor similar variants; therefore, we assessed glucose regulation in two species of deer mice (Peromyscus), a diverse endemic North American group. The prairie deer mouse, P. maniculatus bairdii (BW), and the Oldfield mouse, P. polionotus subgriseus (PO) differ in sexual dimorphism, behavior and habitat. PO animals exhibit better regulatory ability than BW animals, particularly among males, although both species display equivalent insulin levels/responses and non-fasted glucose levels. Hybrid males exhibit a PO glucose challenge response and subsequent analysis of consomic animals implicates Y chromosome variation as the genetic cause. Two pieces of evidence indicate that the ma...