Peripheral Blood Glucose Concentrations Research Articles

Alterations in blood glucose concentration in wild rodents, Holochilus sciureus, naturally infected with Schistosoma mansoni.

The present study aimed to evaluate the changes in peripheral blood glucose concentrations induced by Schistosoma mansoni infection in Holochilus sciureus rodents, a wild reservoir of the parasite. Glucose concentration was measured in the plasma of blood samples using a colorimetric enzymatic test. Biological parameters and S. mansoni burden in each rodent were also verified and correlated with glucose concentrations. A total of 76 H. sciureus were captured, out of which 20 (26%) were infected with S. mansoni (n=13 males and n=7 females). Although the parasite burden was comparable between the sexes, blood glucose concentration was lower in infected males and almost unchanged in females. Furthermore, histopathological data revealed that male rodents had a greater hepatic granulomatous inflammatory reaction than females. In addition, we also confirmed that the weight and total length of the analyzed animals had no effect on glucose levels. Therefore, natural infection with S. mansoni in H. sciureus may have a lower impact on glycemic homeostasis in females, which will help us understand the role of these rodents as reservoirs of S. mansoni.

Energy metabolites, lipid variables and lactation performance of periparturient Murrah buffaloes (Bubalus bubalis) fed on diet supplemented with inorganic chromium.

The aim of this study was to elucidate the effects of chromium (Cr) supplementation as inorganic Cr (CrCl3·6H2O) on energy balance, lipid peroxidation, and lactation performance in periparturient Murrah buffaloes. Twenty-four multiparous Murrah buffaloes according to lactation, parity, body mass, and expected calving date were divided equally. Experimental buffaloes were randomly assigned to four treatment diets: a control diet and three diets with an inorganic Cr supplementation at 0.5, 1.0, and 1.5 mg of Cr/kg dry matter (DM), respectively from 60 days before expected calving date until 60 days of lactation. Milk productions of buffaloes were recorded every day until 60 days in milk. Blood samples were collected at days -60, -45, -30,-21, -15, -7, -3, 0, 7, 15, 21, 30, 45, and 60 days relative to actual calving for determination of plasma glucose, nonesterified fatty acid (NEFA), thiobarbituric acid reactive substance (TBARS), total cholesterol, total protein, albumin, blood urea nitrogen (BUN), and minerals. Adding inorganic Cr to the diet of Murrah buffaloes increased milk yield. Percentage of fat and total solid yield increased significantly through the experiment in the Cr-supplemented group. At the day of calving, buffaloes showed a decrease in dry matter intake (DMI), plasma glucose, and zinc (Zn) and Cr concentrations. In contrast, plasma NEFA, TBARS, and copper (Cu) levels were found highest at the day of calving among all groups. Cr supplementation increased peripheral blood glucose concentration while decreased level of NEFA and TBARS was recorded in Cr-fed buffaloes. Supplemental Cr had no effect on plasma cholesterol, total protein, albumin, and BUN in periparturient period. Dietary Cr supplementation had positive effect on plasma Cr concentration, but the plasma concentration of Cu, Zn, and iron (Fe) was not affected by different dietary Cr level supplementation. The results suggest that dietary inorganic Cr supplementation improved milk yield by reducing negative energy balance and lipid peroxidation in buffaloes during periparturient period.

Effects of a late supper on digestion and the absorption of dietary carbohydrates in the following morning

BackgroundOur previous experiment showed that the light intensity exposed on the subjects during evening time had no effect in the following morning on the efficiency of the digestion and absorption of dietary carbohydrates ingested at a usual suppertime. People who keep late hours usually have a late suppertime; thus, we examined the effects of a late suppertime on gastrointestinal activity in the following morning in comparison to that of a usual suppertime.MethodsTwelve female university students volunteered as paid participants. The breath hydrogen test was carried out to estimate the amount of unabsorbed dietary carbohydrates and the percentage of the total amount of dietary carbohydrates in the breakfast that were unabsorbed, as well as to estimate oro-cecal transit time. The respiratory quotient was also measured to find the ratio of carbohydrates/lipid metabolism in the post-breakfast state. Subjects’ peripheral blood glucose concentration was measured by a blood glucose meter. The subjects participated under two different experimental conditions: with a usual suppertime (having supper at 18:00) and a late suppertime (having supper at 23:00).ResultsThe efficiency of the digestion and absorption of dietary carbohydrates in the breakfast under late suppertime conditions was higher than that under usual suppertime conditions. Usual or late suppertime had no effect on the ratio of carbohydrates to lipids oxidized after the subjects had breakfast. There were significant differences in the blood glucose level between the two conditions at 30, 60, 120, 150, and 180 minutes after having breakfast, whereas the mean blood glucose level under late suppertime conditions was significantly higher than under usual suppertime conditions.ConclusionsHaving a late supper showed a worse effect on postprandial serum glucose profiles the following morning. This study confirmed that keeping our usual meal timing is important for our health.

Sources of Variation in Blood Glucose Concentrations of Free-Living Birds

Three issues concerning avian peripheral blood glucose concentrations that require more investigation are: (a) whether they are as variable and high in free-living as in captive and domesticated adults, (b) the sources of variation in adult concentrations and (c) if and how they change during nestling development. Whole blood glucose concentrations (BGlu) of wild adults of four native passerine and one exotic dove species varying in mass and diet were measured in south-east Australia. There was significant inter-specific variation in BGlu, but the range in mean values (11.1 to 17.0 mmol L−1) conformed with that published for many adult captive and domestic birds of similar size and was well above that for adult mammals of comparable mass. BGlualso varied markedly intra-specifically in four species (coefficients of variation 17.5-32%). Trapping procedure and timing of sampling did not explain this variation, but adult body mass was associated with BGluin two species. If whole blood haemoglobin concentrations (Hb) reliably reflect body condition, most of the adults sampled were in good condition. Wild nestling Welcome swallows (Hirundo neoxena) and Spotted doves (Streptopelia chinensis), respectively, underwent 20% and 40% continuous, linear, developmental increases in BGlu. Swallows fledged with a mean BGlu23% greater than, and doves with a mean similar to, that of adults. The developmental increase probably reflected an increase in metabolic rate as nestlings gained mass and became more active.

Change of gene rstn expression in brain tissues after traumatic brain injury

Objective To investigate the change of gene rstn expression in brain tissues following traumatic brain injury (TBI). Methods A total 90 SD rats were involved in the study and divided into normal control group (5 rats), sham operation group (10 rats), mild, moderate and severe trauma groups (25 rats per group). Rat model was made with sap pressure clash method and RT-PCR assay was employed to detect expression change of gene rstn at 3, 6, 24, 72 h and 1, 2, 4 weeks after TBI. The change of peripheral blood glucose concentration was measured in moderate trauma group to observe its relationship with gene rstn expression in brain tissue. Results Postoperative expression of gene rstn was increased in severe trauma group at 24 hours, in moderate trauma group at 72 hours and in mild trauma group at four weeks (P＜0.05). The expression of gene rstn was increased in hippocampus, thalamus and cortex of all trauma groups at four weeks postoperatively, when the hippocampus showed the highest expression while the thalamus showed the least (P＜ 0.05). Moreover, the expression of gene rstn showed high level in injury side but low level in contralateral side in different districts (P ＜ 0.05). The expression of gene rstn was increased the most obviously in severe trauma group (P ＜0.05). Peripheral blood glucose concentration showed a linearity positive correlation with gene rstn expression in brain tissue (R=5.32,P＜0.05). Conclusions Expression of gene rstn shows obvious increase after TBI, and the time course correlates with the injury severity. The gene rstn expresses the most in the ipsilateral hippocampus. There shows a certain correlation between gene rstn expression and peripheral blood glucose concentration in brain tissues after TBI. Key words: Brain injuries,traumatic; Gene rstn; Tim-course change; Blood glucose concentration

Inhibitory effects of hyperglycemia on neural activity of the vagus in rats.

Although it has been demonstrated that hyperglycemia inhibits gastrointestinal (GI) motility, its inhibitory mechanism remains unclear. Electrophysiological study. As GI motility is under the influence of the vagus, we studied the effects of hyperglycemia on neural activity of the dorsal motor nucleus of vagi (DMV) in anesthetized rats. A tungsten electrode was placed in the left side of the DMV area and extracellular electrical signals from the electrode were recorded. Single unit nerve activity was identified by the discriminator. D-glucose infusion elevated the peripheral blood glucose concentration from 3.4-5.9 mm to 12.0-21.8 mm and the neural firing of the DMV was significantly reduced by D-glucose infusion. After the 30 min D-glucose infusion, saline was re-infused for 90 min. Blood glucose level returned to 6.5-7.8 m m and the neural firing partially recovered 90 min after the saline re-infusion. There was a significant negative correlation observed between the counts of neural spikes and blood glucose concentrations ( r=0.84, p<0.01). It is suggested that hyperglycemia impairs GI motility by inhibiting vagal efferent activity. A recent study in intensive care unit (ICU) patients demonstrated that uncontrolled hyperglycemia is associated with poor outcomes. We propose that glycemia control is crucial in ICU patients to maintain the GI motility and vagus nerve activity.

Gastric distension-induced pyloric relaxation: central nervous system regulation and effects of acute hyperglycaemia in the rat.

1. The pylorus plays an important role in the regulation of gastric emptying. In addition to the autonomic neuropathy associated with long-standing diabetes, acute hyperglycaemia per se has effects on gastric emptying. In this study, the role of the central nervous system in modulating the effects of hyperglycaemia on gastric distension-induced pyloric relaxation was investigated. 2. Gastric distension-induced pyloric relaxation was significantly reduced by subdiaphragmatic vagotomy, hexamethonium (20 mg kg(-1)) and N (G)-nitro-L-arginine methyl ester (L-NAME; 10 mg kg(-1)), a nitric oxide synthase (NOS) biosynthesis inhibitor, in anaesthetized rats. In contrast, neither splanchnectomy nor guanethidine (5 mg kg(-1)) had an effect. 3. An intravenous (I.V.) infusion of D-glucose (20 %) for 30 min, which increased blood glucose concentrations from 5.4 to 12.8 mM, significantly inhibited gastric distension-induced pyloric relaxation. 4. An intracerebroventricular (I.C.V.) injection of D-glucose (3 micromol) also significantly inhibited gastric distension-induced pyloric relaxation without affecting peripheral blood glucose concentrations. 5. I.V. infusion of D-glucose significantly elevated hypothalamic neuropeptide Y (NPY) concentrations. 6. Intracerebroventricular (I.C.V.) administration of NPY (0.03--3 nmol) and a Y1 receptor agonist, [leu(31), pro(34)] NPY (0.03--3 nmol), significantly inhibited gastric distension-induced pyloric relaxation in a dose-dependent manner. 7. I.C.V. administration of a Y1 receptor antagonist, BIBP 3226 (30 nmol), and of a NPY antibody (titre 1:24 000, 3 microl) abolished the inhibitory effects of hyperglycaemia on gastric distension-induced pyloric relaxation. 8. Taken together, these findings suggest that gastric distension-induced pyloric relaxation is mediated via a vago-vagal reflex and NO release. Acute hyperglycaemia stimulates hypothalamic NPY release, which, acting through the Y1 receptor, inhibits gastric distension-induced pyloric relaxation in rats exposed to acute elevations in blood glucose concentrations.

Maintenance of high-energy brain phosphorous compounds during insulin-induced hypoglycemia in men. 31P nuclear magnetic resonance spectroscopy study.

31P nuclear magnetic resonance (NMR) spectroscopy allows noninvasive studies of cerebral energy-rich phosphorous compounds in humans. In an attempt to characterize the relationship between peripheral blood glucose concentrations and whole-brain phosphate metabolism during insulin-induced hypoglycemia, 31P NMR spectra were obtained before and after intravenous injection of insulin (0.15 IU/kg body wt) in six men. Compared with prehypoglycemic measurements, no significant changes were found in brain content of Pi, sugar phosphates, phosphocreatine, phosphodiesters, and ATP, and brain pH remained constant during the experiment. These results show that the integrated brain profile of energy-rich phosphorous compounds is unaffected by experimental insulin-induced hypoglycemia in humans.

Effect of cortisol on utilization and hepatic release of glucose in the marsupial brush-tailed opossum, Trichosurus vulpecula.

Brush-tailed opossums were prepared surgically with indwelling heatic and jugular venous catheters for blood sampling without disturbance in the conscious state. Hepatic extraction of Rose Bengal was 21 +3 (s.d.) % and hepatic clearance, used as a measure of hepatic blood flow, was 42.5 +7 ml/kg/min. Hepatic relaease of new glucose, calculated from the thorias vena caval-hepatic venous difference in glucose specific activity at equilibrium during i.v. infusion of [14C]glucose and hepatic blood flow, was 3.5 + o.0 mg/kg/mim. This was not changed by i.v. infusions of 10% ethanolic aline or cortisol in ethanolic saline, at 1mg/kg/h for 90 min, although the cortisol infusion caused the peripheral blood glucose concentration to rise form 56.5 + 7.3 to 83.2 + 10.3 mg/100ml. The rate of metabolic clearance of glucose fell from 6.1 +1.1 to 4.2 +0.9 ml/kg/min during i.v. cortisol infusion. Daily i.m. injection of 1 mg cortisol accetate/kg for 5 days caused an increase in hepatic new glucose release to 8.0 + 1.6 mg/kg/min. The findings support the propostion that, in the marsupial, the short-term effect of cortisol on plasma glucose concentration is due to inhibition of peripheral glucose utilization, whereas the long-term effect is due to increased hepatic glucose production.