Decrease In Glucose Concentration Research Articles

Hypoglycemic Effects of Insoluble Fiber Rich Fraction of Different Cereals and Millets

Dietary fibers are important for their hypoglycemic effect, hypolipidemic effect; lowering serum cholesterol hence helps in prevention of atherosclerosis, antitoxic effect and anti-cancerous effect. It also helps in control of gastro intestinal disorders like gall stone, irritable bowel syndrome, constipation, inflammatory bowel disease etc. Beneficial effects of cereal fibers are frequently discussed in the context of whole grain consumption; unrefined whole grains and bran products are highly complex substances containing both soluble and insoluble dietary fiber as well as other biologically active substances e.g. polyphenols, antioxidants, vitamins, trace minerals, phytoestrogens, lipids, proteins, and starch. Research on minor millets and its food value is in its infancy and its potential vastly untapped. So the present study was undertaken to evaluate the in-vitro hypoglycemic effect of insoluble fibers from locally available whole grain of millets and cereals like kodo millet (Paspalum scrobiculatum), Proso millet (Panicum miliaceum), Barnyard millet (Echinochloa frumentaceae), Finger millet (Elusine coracana), wheat (Triticum aestivum) and Great millet (Sorghum vulgare) from tribal belt of Odisha. Proximate analysis of the cereals and millet grains revealed that these grains are rich in crude fiber, total ash and crude protein content. The nutritional composition is better than most of the commonly used grains. In general the crude fiber and ash content of the bran samples were more as compared to the grains. Glucose adsorption capacity (GAC) at 5 Millimole/l concentration of glucose was almost similar in IDF of all the millets and wheat ranging from 0.04 ± 0.01 in case of Barnyard millet IDF to 0.06 ± 0.01 in Sorghum, Ragi and Kodo. Glucose absorption capacity at 5 Millimole/l concentration of glucose was highest in Ragi fibers but at higher concentration of glucose it was highest in wheat fibres. GAC increases with increase in glucose concentration in all the cases studied. In most samples WIS showed maximum GAC. Maximum GAC was found at 50 mM/lit in Ragi (Finger millet) IDF and lowest value was found at 10 mM/lit in jhipiri (Barnyard millet) IDF and wheat AIS. In case of glucose diffusion and GDRI, in all types of fiber, it showed decrease in glucose concentration in the dialysate with addition of fiber than in control (without fiber), indicating that addition of fiber decreased diffusion of glucose through dialysis membrane which simulates the function of membrane of small intestine. The glucose concentration in the dialysate though increases with increase in time but remains lower to that of glucose value in control. When GDRI values were compared it showed lowest value in case of IDF than AIS and WIS in all the six samples. Effect of insoluble fibers on alpha-amylase activity indicate that glucose production rate is highest in kodo (kodo millet) AIS but lowest in sorghum (Great millet) IDF. When residual amylase activity was compared it showed highest values in Ragi (Finger millet) AIS and lowest values in gunji (Proso millet) IDF.

Effects of intracisternal and intravenous dexmedetomidine on ischemia-induced brain injury in rat: a comparative study

To compare the effect of dexmedetomidine administered by intracisternal route with by intravenous route on brain tissue of rat after incomplete cerebral ischemia. Cerebral ischemia was produced by the combination of right common carotid artery occlusion and hemorrhagic hypotension during 30 minutes. Thirty minutes before the ischemia, 0.1 ml 0.9% NaCl (Group SIC, n=6) or 9 μg/kg dexmedetomidine (Group DIC, n=6) was administered into the cisterna magna. For the intravenous groups, 9 μg/kg dexmedetomidine (Group DIV, n=6) or 0.9% NaCl (Group CONTROL, n=6) 5 ml/kg/h was given in 2 hours. After 24 hours, the lipid peroxidation levels were measured in the brain tissue and plasma. Hippocampal formations were used for histopathological examination. Intravenous dexmedetomidine produced a decrease in baseline mean arterial blood pressure and plasma glucose concentrations. There was a significant difference between the DIV group and DIC, SIC, CONTROL groups regarding the brain lipid peroxidation levels (p < 0.001, p < 0.001, p=0.001, respectively), and regarding the picnotic neuronal cell count (p < 0.001, p=0.01, p=0.009, respectively). Mean plasma lipid peroxidation levels of the DIV group was different from the DIC group (p=0.003). Systemically administered dexmedetomidine had neuroprotective effect in ischemia-induced neuronal damage, but centrally administered dexmedetomidine did not.

Ketogenic diet increases concentrations of kynurenic acid in discrete brain structures of young and adult rats

Targeting mechanisms that result in increased concentrations of kynurenic acid (KYNA) in the brain has been considered as a therapeutic approach for the treatment of epilepsy and certain neurodegenerative disorders. Recently, KYNA has been implicated in the effects produced by the high-fat and low-protein/carbohydrate ketogenic diet (KD) in a report demonstrating an increased production of KYNA in vitro by one of the ketone bodies, β-hydroxybutyrate, elevated by the KD. To further explore this association, brain concentrations of KYNA were compared in young (3 weeks old) and adult (8–10 weeks old) rats that were chronically exposed to the KD and regular diet. Exposure to the KD resulted in the anticipated elevations of β-hydroxybutyrate with accompanying decreases in glucose concentrations. In comparison to rats fed the regular diet, KYNA concentrations were significantly (p < 0.05) increased in the hippocampus (256 and 363% increase in young and adult rats, respectively) and in the striatum (381 and 191% increase in young and adult rats, respectively) in KD-fed rats. KD-induced increases in KYNA concentrations in young versus adult rats in the hippocampus and striatum were comparable (p > 0.05). Exposure to the KD had no effect on KYNA concentrations in the cortex of young and adult rats (p > 0.05). In summary, chronic exposure to the KD resulted in several-fold increases in KYNA concentrations in discrete brain structures in the rats. Thus, the relevant clinical question for further exploration is whether KD-induced increases in KYNA concentrations can translate into clinically significant improvements in neuropsychiatric diseases associated with KYNA hypofunction.

A short bout of stair climbing–descending exercise attenuates postprandial hyperglycemia in middle-aged males with impaired glucose tolerance

Exercise is a useful modality to ameliorate postprandial hyperglycemia. Here we show that a short bout (∼6 min) of stair climbing-descending exercise (STAIR) starting at 90 min after meal accelerates the decrease in blood glucose concentrations in middle-aged sedentary men with impaired glucose tolerance, although STAIR is easy to perform and keeps the exercise intensity at a moderate level.

Layer-by-layer self-assembly of functionalized graphene nanoplates for glucose sensing in vivo integrated with on-line microdialysis system

In this work, a novel amperometric biosensor for hydrogen peroxide was fabricated through the layer-by-layer (LBL) self-assembling of amine-terminated ionic liquid (IL-NH 2), and sulfonic acid (SO 3 −) functionalized graphene by covalent bonding. The modification of the two functionalities introduced positive and negative charge onto the surface of graphene respectively, thus facilitating the formation of a multilayer film denoted with {IL-RGO/S-RGO} n through electrostatic interaction and further immobilization of glucose oxidase (GOx). The resulting {IL-RGO/S-RGO} n /GOx/Nafion biosensor displayed an excellent response to glucose at a potential of −200 mV. Combined with on-line microdialysis system, the glucose biosensor in the on-line system showed good linear range from 10 μM to 500 μM with the detection limit of 3.33 μM (S/N = 3). Consequently, the basal level of glucose in the striatum of anesthetic rats was calculated to be 0.376 ± 0.028 mM (mean ± s.d., n = 3). The {IL-RGO/S-RGO} n /GOx/Nafion biosensor was further applied for in vivo sensing of the glucose level in the striatum when rats received intraperitoneal (i.p.) injection of 30 μL insulin, which resulted in an obvious decrease in the extracellular concentration of glucose within 30 min. The method was proved to be sensitive and reproducible, which enabled its promising application in physiology and pathology.

Increasing the folic acid content of maternal or post-weaning diets induces differential changes in phosphoenolpyruvate carboxykinase mRNA expression and promoter methylation in rats

Environmental exposures throughout the life course, including nutrition, may induce phenotypic and epigenetic changes. There is limited information about how timing affects the nature of such effects induced by a specific nutritional exposure. We investigated the effect of increased exposure to folic acid before birth or during the juvenile-pubertal period in rats on the epigenetic regulation of glucose homeostasis. Rats were fed either a folic acid-adequate (AF; 1mg/kg feed) or a folic acid-supplemented (FS; 5mg/kg feed) diet from conception until delivery and then an AF diet during lactation. Juvenile rats were fed either the AF or the FS diet from weaning for 28d and then an AF diet. Liver and blood were collected after a 12h fast between postnatal days 84 and 90. Maternal FS diet increased plasma glucose concentration significantly (P<0·05) in females, but not in males. Post-weaning FS diet decreased glucose concentration significantly in females, but increased glucose concentration in males. There were no effects of the FS diet on phosphoenolpyruvate carboxykinase (PEPCK) mRNA expression in males, while the pattern of expression was related to plasma glucose concentration in females. The FS diet induced specific changes in the methylation of individual CpG in females, but not in males, which were related to the time of exposure. Methylation of CpG -248 increased the binding of CCAAT-enhancer-binding protein β to the PEPCK promoter. Together, these findings show that both the period during the life course and sex influence the effect of increased exposure to folic acid on the epigenetic regulation of PEPCK and glucose homeostasis.

Chronic ritodrine treatment induces refractoriness of glucose-lowering β2 adrenoceptor signal in female mice

Adverse events in tocolytic therapy with β2-adrenergic agents compromise cardiovascular and non-cardiovascular functions, including blood glucose regulation and liver function. Here, we have examined the effects of the β2 agonist ritodrine on glucose metabolism and liver injury in mice. Under fasting conditions, ritodrine significantly increased serum insulin levels and decreased glucose concentrations. This contrasts with the β2 agonist-induced hyperglycemia observed in previous studies on humans and other animals. After 14days of ritodrine treatment, the mice showed a decrease in the total mass of epididymal fat pads, whereas their body weights increased significantly. Chronic ritodrine treatment attenuated the glucose-lowering effect observed during acute administration. Ritodrine also significantly increased serum levels of liver enzymes, which returned to control levels after 14days of treatment. Thus, ritodrine responsiveness changes between acute and chronic treatment, indicating that close monitoring of blood glucose and serum liver enzymes is necessary in patients with reduced glucose tolerance. The findings reported here of glucose homeostasis in mice provide a unique opportunity to understand refractoriness of β2-adrenoceptor signaling in response to β2 agonists during the course of treatment.

The effects of different environmental conditions on thermoregulation and clinical and hematological variables in long-distance road-transported calves1

The aim of this study was to investigate the effects of long-distance road transport (19 h, from Poland to Italy) during 2 seasons (summer vs. winter) on clinical and hematological variables in calves. The environmental temperature range that could compromise the thermoregulation system (thermal stress) of the calves was tested. For the 7 Holstein calves in each transport, the BW and rectal temperature (RT) were measured, and blood samples were collected at the farm of origin, before loading at the transit center (T2), after unloading at the farm of destination (T3), and 1, 2, 3, and 4 d after arrival. The body temperature (BT) and heart rate (HR) were continuously monitored from T2 to T3. The data were statistically analyzed according to a mixed model that considered the fixed effects of transport (repeated measurements), season of journey, and their interaction. Within the observed temperature-humidity index (THI) range (30 to 80), effective thermoregulation allowed the calves to maintain their BT with small physiologic changes to prevent thermal stress, particularly in the summer. With no seasonal differences, the HR was greater at loading than unloading (120 vs. 115 beats per min; P = 0.012). As for the transport effect, the BW was less (P < 0.001) after unloading, and the RT was greater (P = 0.004). This effect was more marked in summer. The hematological variables indicated a moderate effect of transport on the hydration condition, reactive and muscular systems, and metabolism, although hematocrit (P = 0.004), erythrocytes, cortisol, NEFA, β-hydroxybutyrate, lactate, creatine kinase, lactate dehydrogenase, and aspartate aminotransferase activity (P < 0.001), and total protein (P = 0.007) were greater after unloading. This was confirmed by a moderate decrease in total leukocytes (P = 0.031) and glucose concentration (P = 0.002). The changes in the clinical variables were similar for both seasons even though in the summer, hematocrit (P < 0.001), urea (P = 0.008), and total protein (P = 0.010) increased and glucose concentration (P = 0.038) decreased. In conclusion, the data did not show a pronounced effect attributable to the season of the journey. Long-distance road transport leads to notable changes in clinical and hematological variables at the end of the journey. However, these variables remained within their physiological ranges and returned to basal values within a few days after the journey.

GLUT12: a second insulin-responsive glucose transporters as an emerging target for type 2 diabetes.

GLUT12: a second insulin-responsive glucose transporters as an emerging target for type 2 diabetes.

The effect of hematocrit on the results of measurements using glucose meters based on different techniques

The aim of the study was to evaluate the effect of hematocrit (HCT) on glucose meter assays based on different measurement techniques. This paper studied glucose meters utilizing the glucose dehydrogenase reaction and four measurement techniques: colorimetry (HemoCue), reflectometry (Accu-Chek Active), amperometry (Optium Xido) and coulometry (Optium Omega). The EDTA venous blood samples HCT were modified by adding or removing defined aliquots of plasma. Glucose concentration was measured using each meter in 27 batches of blood samples, with HCT ranging from 20% to 60% in 10% increments. The data were analyzed using repeated measures models and a linear random effects model. A significant relationship between HCT and glucose reading in all meters was found and, for all meters except Optium Xido, there was a significant modification of this relationship by glucose level. The relative decrease in glucose concentration per 1% increase of the HCT value varied from 0.30% for Optium Omega in samples with glucose concentrations <5.55 mmol/L to 1.37% for Optium Xido in the same stratum (p<0.0001). The 5% glucose meter error (the ADA recommendation) was reached in the <5.55 mmol/L stratum after HCT change by 3.9%-16.7%. There is a significant continuous effect of HCT on measurement accuracy of glucose meters across its wide range of values and glucose concentrations. The most sensitive to the HCT interference was the system utilizing amperometric technique (Optium Xido) followed by the one with reflectometric technique (Accu-Chek Active), while the systems with the coulometric technique (Optium Omega) or colorimetric measurements in whole blood haemolysate (HemoCue) were less sensitive.

Exercise in Closed-Loop Control: A Major Hurdle

People with type 1 diabetes mellitus (T1DM) are at risk for exercise-induced hypoglycemia. Prevention of such hypoglycemia in a closed-loop setting is a major challenge. Markers for automated detection of physical activity could be heart rate (HR) and body acceleration counts (AC). Correlations between HR, AC, and glucose concentrations before and after moderate intensity exercise were examined in T1DM patients during open- loop control. Eleven T1DM subjects treated with an insulin pump performed moderate intensity exercise of 30 min. Glucose profiles, insulin concentrations, HR, and acceleration were measured. Mean (range) glucose decrease during exercise was 1.4 (0 to 3.3) mmol/liter. The mean increase in HR was 45.2 beats per minutes (15 to 106 bpm). Mean increase in AC was 18,000 (3,000 to 25,000). No correlations were seen between the glucose drop and HR or AC. A trend was observed between the increase in HR and increase in AC. Moderate intensity exercise resulted in increased HR and body AC while it decreased glucose concentrations but, in this real-time setting, no association could be demonstrated between the glucose decrease and increase in HR or AC.

Validation de la qualité pharmaceutique de préparations de [6,6- 2H 2]-glucose en solution aqueuse administrées par voie parentérale pour la mesure de l’insulino-résistance dans le cadre d’essais cliniques

Deuterated glucose ([6,6-(2)H(2)]-glucose) is a stable isotopic tracer administered parenterally in healthy volunteers, obese or diabetic patients in clinical trial to study glucose metabolism during euglycemic hyperinsulinemic clamps. In accordance with the Health Authorities on drug safety, we evaluated the pharmaceutical quality of this preparation for biomedical research with a stability study. After pharmaceutical qualification of the raw material, the [6,6-(2)H(2)]-glucose was dissolved in water for injection, then sterile, filtered under positive pressure of nitrogen and then autoclaved. Two batch products (500mg/10mL and 2g/15mL) were sampled to evaluate glucose alteration, isotope shift, limpidity, apyrogenicity and sterility at regular intervals for 2 years. Deuterated glucose solutions were stored in the dark, at +2°C+8°C, in type II glass bottles. Neither significant decrease of glucose concentration nor pH variation were observed for 2 years. The 5-hydroxymethylfurfural concentration was below the human harmful levels, attesting a non-generation of metabolites during autoclaving. Isotopic enrichment higher than 99% reflected the stability of deuterated label on the 6-carbon of glucose molecules. The non-visible particle concentration below the minimal permissible concentration tolerated by the European Pharmacopoeia and the absence of bacterial endotoxin and bacterial growth attested limpidity, apyrogenicity and sterility of the [6,6-(2)H(2)]-glucose solutions. After the 2-year study, 500mg/10mL and 2g/15mL deuterated glucose solutions stored in the dark at +2°C+8°C were stable in aqueous solution, allowing to ensure safety administration for human clinical trials using euglycemic hyperinsulinemic clamps.

Cerebral metabolism after early decompression craniotomy following controlled cortical impact injury in rats

<title/>After traumatic brain injury, a cascade of metabolic changes promotes the development of secondary brain damage. In this study, we examined metabolic changes in rats in the acute stage after trauma. Furthermore, we investigated the effect of a very early decompression craniotomy on intracranial pressure (ICP) and on metabolic parameters. For this study, a moderate controlled cortical impact injury (CCII) on rats was performed. The observation time was 180 minutes after trauma. ICP was measured continuously and microdialysate samples were collected every 30 minutes from the peri-contusional region. As representative metabolic parameters, glutamate, lactate, lactate/pyruvate ratio (L/P ratio), and glucose concentrations were measured. Compared to sham-operated animals, a significant, sustained decrease in glucose concentration and increase in L/P ratio occurred immediately after CCII. Additionally, delayed increase in lactate and glutamate concentrations occurred 60 minutes after trauma. After this initial peak, glutamate concentrations declined continuously via the observation time and reached levels comparable to sham-operated animals. In our model, thus we could detect a very early deterioration of glucose utilization and energy supply after trauma that recovered, due to the moderate intensity of the trauma, within 60 minutes without leading to ischemia in the peri-contusional region. Following decompression craniotomy, the increase of intracranial pressure could be reduced significantly. Any significant beneficial effects on metabolic changes, however, could not be proven in this very early stage after moderate CCII.

Interaction of Aqueous Extract of Trigonella Foenum-Graecum Seeds with Glibenclamide in Streptozotocin Induced Diabetic Rats

Problem statement: Interaction between herbs and drugs may increase or decrease the pharmacological or toxicological effects of either component. Herb traditionally used to decrease glucose concentrations in diabetes could theoretically precipitate hypoglycaemia if taken in combination with conventional drugs. Approach: The present study was undertaken to determine the interaction of Glibenclamide, a Sulphonylurea with Trigonella foenum-graecum seed extract, an herbal drug widely used as a antidiabetic agent. The pharmacodynamic interaction was evaluated in streptozotocin induced diabetic rats. Glibenclamide was given orally in two different doses of 0.25 and 0.50 mg kg-1. Trigonella seed extract was administered at a dose of 20 mL kg-1. The blood glucose estimation was carried out. Results: Both glibenclamide and Trigonella seed extract showed hypoglycemic effect. The hypoglycemic effect observed with combination of glibenclamide and Trigonella seed extract was significantly more than either of drug given alone. Conclusion: It is concluded that Trigonella seed extract shows synergistic effect with glibenclamide. This could be important in reducing the dose of glibenclamide to achieve enhanced therapeutic effect with minimum adverse effect.

ATP-binding cassette transporter G1 protects against endothelial dysfunction induced by high glucose

IntroductionIt is known that hyperglycaemia can contribute to defects in endothelial function, which is the early characteristic of atherosclerosis. ATP-binding cassette transporter G1 (ABCG1), a regulator of reversing cholesterol efflux,...

Rate of fall in blood glucose and recurrent hypoglycemia affect glucose dynamics and noradrenergic activation in the ventromedial hypothalamus

Noradrenergic activity in the ventromedial hypothalamus (VMH) is increased and activates a sympathoadrenal response during hypoglycemia. How the rate at which hypoglycemia develops affects local glucose concentrations and norepinephrine (NE) release was evaluated by placing microdialysis probes into the VMH of male Sprague-Dawley rats receiving insulin (20 mU·kg(-1)·min(-1)) and variable glucose infusions. During a first episode of hypoglycemia, interstitial glucose concentrations in the VMH generally declined at the same rate as plasma glucose; however, the faster hypoglycemia developed, the greater the magnitude of the initial NE release in the VMH (r(2) = 0.72, P < 0.001). Following recurrent episodes of hypoglycemia, VMH glucose decreased at a slower rate than plasma glucose, and the initial NE release was attenuated at the same rates of blood glucose decline. The plasma glucose threshold for the initial NE release in VMH was similar for all groups (∼3.23 mM); however, the VMH glucose threshold was stimulated and was lower when blood glucose declined more slowly (0.86 ± 0.06 vs. 1.06 ± 0.04 mmol/l, P < 0.01). The timing of the initial increase in NE release in VMH corresponded with an increase in plasma epinephrine during the first episode of hypoglycemia but not following recurrent hypoglycemia. Although a decrease in VMH glucose concentration is required for noradrenergic activation in VMH, there does not appear to be a set glucose threshold within the VMH for activation of this response.

EFFECT OF FEED WITHDRAWAL TO REDUCE THE NEGATIVE EFFECT OF HEAT STRESS ON SOME PHYSIOLOGICAL TRAITS AND PRODUCTIVE PERFORMANCE OF BROILER CHICKEN

The aim of this study was to investigate the effect of feed withdrawal in reducing the negative effect of heat stress in broilers subjected to cyclic heat stress (25-36-25) 5C on some productive and physiological traits . Thirty six of broiler chicks (Fawbro) raised on standard condition for the first 3weeks. The experimental treatments were started from 22days of age till the age of marketing (56days).On day 22 of ages the chicks were weighted ,numbered and distributed randomly to four treatments (1) the control(ad Libitum) , (2)feed withdrawal for eight hours(1000-1800) , (3)feed withdrawal for nine hours(900-1800) , (4)feed withdrawal for ten hours(800-1800) with 3 replicates for each treatment. Statistical analysis of data showed No significant differences (p≤0.05) as a result of feed withdrawal for live body weight , average weekly weight gain , feed consumption , feed conversion ratio , Dressing percentage , Red blood cells number , hemoglobin concentration , packed cells volume and relative growth rate in seven and eight weeks . Feed withdrawal resulted in significant decrease (P ≤ 0.05) in blood glucose concentration gradually as the feed withdrawal increase , glycogen concentration in liver for feed withdrawal 10 hours treatments , blood pH and body temperature for feed withdrawal treatments at six and eight weeks . and significant increase(P ≤ 0.05) in , glycogen concentration in heart of feed withdrawal 10 hours . Decrease in mortality.

Clinicopathologic, Gross Necropsy, and Histologic Findings After Intramuscular Injection of Carprofen in a Pigeon (Columba livia) Model

To evaluate the pathologic effects of carprofen in a pigeon model (Columba livia), 52 young adult pigeons were used in a randomized control study design. Sixteen pigeons were randomly assigned to 1 of 3 treatment groups and received carprofen by intramuscular injection at dosages of either 2, 5, or 10 mg/kg once daily for 7 days. Four pigeons served as saline-injected controls. Four pigeons from each group and 1 control pigeon were randomly selected on days 2, 4, 6, and 8 to obtain blood samples and then were euthanatized and submitted for necropsy. Histologic lesions in pectoral muscle, liver, kidney, and digestive tract tissue samples were ranked in severity as 0, normal/not present; 1, minimal; 2, mild; 3, mild to moderate; 4, moderate; 5, moderate to marked; and 6, marked pathologic changes. Two-way analysis of variance (day x dose) and pairwise t tests revealed significant (P < or = .05) mild decreases in total protein and glucose concentrations and marked increases in aspartate aminotransferase and alanine aminotransferase enzyme activities after carprofen treatments. Gross lesions in carprofen-treated pigeons were pale injection sites (23/48 [47.9%]), mottled yellow livers (9/48 [18.8%]), and congestion of small intestines (7/48 [14.6%]). Liver, kidney, and muscle injection sites had significantly increased (P < or = .05) severity of histologic lesions. In pigeons, intramuscular administration of carprofen is associated with increased aspartate aminotransferase and alanine aminotransferase enzyme concentrations, gross lesions in muscle injection sites and liver, and histologic lesions in liver and muscle.

Effect of dietary supplementation with unprocessed and ethanol-extracted apple pomaces on caecal fermentation, antioxidant and blood biomarkers in rats

The present 4-week study on growing Wistar rats was aimed at assessing the potential advantages of dietary supplementation with apple pomace containing both fibre and polyphenols, which enables nutritional exploitation of the physiological traits of both compounds. A total of twenty-four rats, assigned to the control (C), group fed with a diet supplemented with 14% of processed apple pomace (A) and group fed with a diet supplemented with 15% unprocessed apple pomace (AP) groups, were fed the following iso-fibrous diets: control, ethanol-extracted and unprocessed apple pomaces (low and high level of dietary polyphenols, i.e. 0·002 and 0·018%, respectively). To measure the animal response, parameters describing the caecal fermentation, antioxidative status and lipoprotein profile of rats were assessed. Both dietary apple pomaces were found to significantly (P≤0·05) decrease caecal pH and ammonia concentration, microbial β-glucuronidase activity as well as to increase caecal SCFA concentration in comparison to the control diet. The unprocessed pomace did not suppress caecal fermentation. Unlike the extracted one, the dietary apple pomace rich in polyphenols significantly (P≤0·05 v. C group) increased erythrocyte superoxide dismutase activity and serum antioxidant capacity of lipid-soluble substances and significantly (P≤0·05 v. C group) decreased amounts of thiobarbituric acid-reactive substances in liver tissue. Moreover, the 4-week administration of the AP diet to rats evoked a significant decrease in serum glucose concentration (P≤0·05 v. C and A groups). In conclusion, the results demonstrated that the polyphenol-rich fibre complexes from apple pomace exerted positive effects on gastrointestinal physiology and antioxidant status of rats.

Factors Affecting the Glucose Response to Insulin Injection in Mares: Epinephrine, Short- and Long-Term Prior Feed Intake, Cinnamon Extract, and Omega-3 Fatty Acid Supplementation

Five experiments were conducted with mares to better define factors that might affect the assessment of insulin sensitivity via direct insulin injection, and to then apply this method of assessing insulin sensitivity to trials which tested two potential supplements for improving poor insulin sensitivity in horses. The experiments assessed the effects of the following: (1) previous administration of epinephrine, (2) overnight feed deprivation versus hay or pasture consumption, (3) 10-day acclimatization to hay in a dry lot versus pasture grazing, (4) cinnamon extract supplementation, and (5) fish oil supplementation on insulin sensitivity. Mares of known high and low insulin sensitivities were used in the first three experiments, whereas mares with low insulin sensitivities were used in the supplement trials. Epinephrine administration increased blood glucose concentrations ( P < .05) and prevented the insulin-induced decrease in blood glucose concentrations in both sensitive and insensitive mares. Overnight feed deprivation decreased ( P < .06) insulin sensitivity relative to overnight ad libitum access to hay, and both regimens resulted in reduced insulin sensitivity relative to overnight pasture availability; sensitive and insensitive mares responded similarly except when kept on pasture ( P = .0854). Ten days of hay consumption in a dry lot reduced ( P < .05) insulin sensitivity in insensitive mares, but not in sensitive mares, relative to pasture grazing. Supplementation with cinnamon extract or fish oil had no effect on insulin sensitivity of mares with known low insulin sensitivity under the conditions of these experiments.