Determination Of Blood Glucose Concentration Research Articles

Assessment of the influence of the mineral complex of rutin on the degree of expression of anti-diabetic activity

Assessment of the influence of the mineral complex of rutin on the degree of expression of anti-diabetic activity

Inhibition of mitochondrial fission by Drp-1 blockade by short-term leptin and Mdivi-1 treatment improves white adipose tissue abnormalities in obesity and diabetes

BackgroundObesity and type 2 diabetes are chronic diseases characterized by insulin resistance, mitochondrial dysfunction and morphological abnormalities. ObjectiveWe have investigated if dysregulation of mitochondrial dynamics and biogenesis is involved in an animal model of obesity and diabetes. MethodsThe effect of short-term leptin and mdivi-1 – a selective inhibitor of Drp-1 fission-protein – treatment on mitochondrial dynamics and biogenesis was evaluated in epididymal white adipose tissue (WAT) from male ob/ob mice. ResultsAn increase in Drp-1 protein levels and a decrease in Mfn2 and OPA-1 protein expression were observed with enhanced and sustained mitochondrial fragmentation in ob/ob mice compared to wt C57BL/6 animals (p < 0.05). The content of mitochondrial DNA and PGC-1α mRNA expression –both parameters of mitochondrial biogenesis– were reduced in ob/ob mice (p < 0.05). Treatment with leptin and mdivi-1 significantly increased mitochondrial biogenesis, improved fusion-to-fission balance and attenuated mitochondrial dysfunction, thus inducing white-to-beige adipocyte transdifferentiation. Measurements of glucose and lipid oxidation in adipocytes revealed that both leptin and mdivi-1 increase substrates oxidation while in vivo determination of blood glucose concentration showed decreased levels by 50% in ob/ob mice, almost to the wt level. ConclusionsPharmacological targeting of Drp-1 fission protein may be a potential novel therapeutic tool for obesity and type 2 diabetes.

Microneedles in diagnostic, treatment and theranostics: An advancement in minimally-invasive delivery system.

Microneedle (MN) technology plays an important role in biomedical engineering for their less intrusive access to the skin due to minimally or painless penetration, enhancement of drug permeability, improvement of detectability of biomolecules in the epidermal and dermal layers with therapeutic efficacy and safety. Furthermore, MNs possess some major disadvantages like difficulty in scale-up technique, variation in drug delivery pattern with respect to external environment of skin, blockage of arrays due to dermal tissues, induction of inflammation or allergy at the site of administration and restriction of dosing range based on the size of active. Additionally, microneedle acts as a transdermal theranostic device for monitoring the physiological parameters in clinical studies. The investigation of drug transfer mechanisms through microneedles includes coat and poke, poke and flow, poke and patch and poke and release method. This review article discusses different categories of microneedles with fabrication methods such as photolithography, laser cutting, 3D printing, etc. in therapeutic applications for treating cancer, diabetes, arthritis, obesity, neurological disorders, and glaucoma. Biosensing devices based on microneedles may detect target analytes directly in the interstitial fluid by penetrating the stratum corneum of the skin and thus microneedles-based devices can be considered as a single tool in diagnostic sensing and therapeutic administration of drugs inside the body. Moreover, the clinical status and commercial availability of microneedle devices are discussed in this review article to offer new insights to researchers and scientists. Continuous monitoring particularly for the determination of blood glucose concentration is one of the most important requirements for the development of next-generation healthcare devices. The aim of this review article focuses mainly on the theranostic applications of microneedles in various medical conditions such as malaria, glaucoma, cancer, etc.Graphical abstract

Non-Invasive Glucose Monitoring: Application and Technologies

The chronic metabolic disorder, diabetes mellitus is a fast-growing global problem with huge social, health, and economic consequences. The prevailing method for determination of blood glucose concentration is using a self-monitoring glucose meter. Most of the commercially available devices for glucose measurement are invasive or minimally invasive. Invasive devices used for blood glucose monitoring are painful whereas minimal invasive devices have limited time span and stability.

Relationship between MIF expression and obese-induced abolition of sevoflurane preconditioning-induced cardioprotection in mice

Objective To evaluate the relationship between macrophage migration inhibitory factor (MIF) expression and obese-induced abolition of sevoflurane preconditioning-induced cardioprotection in mice. Methods Forty-eight male C57BL/6J mice, aged 4 weeks, were divided into 2 groups(n=24 each)using a random number table method: normal diet group (Lean group) and high-fat diet group (Obese group). Lean group were fed a normal diet (10% kcal) for 12 weeks, while Obese group were fed a high-fat diet (60% kcal) for 12 weeks.The weight of mice was measured.Blood samples were collected from the tail vein for determination of blood glucose concentrations, and plasma concentrations of total cholesterol, triglyceride, insulin and leptin.After measurement of the parameters mentioned above, Lean group and Obese group were divided into 3 subgroups (n=8 each) using a random number table method: sham operation groups (L-Sham group, O-Sham group), myocardial ischemia-reperfusion groups (L-IR group, O-IR group) and sevoflurane preconditioning groups (L-IR+ Sev group, O-IR+ Sev group). The mice were anesthetized and their hearts were immediately removed and retrogradely perfused in a Langendorff apparatus with an oxygenated K-H solution at 37 ℃.Hearts were continuously perfused with K-H solution for 115 min in L-Sham and O-Sham groups.Hearts were subjected to global ischemia for 25 min, followed by 60-min reperfusion after being retrogradely perfused with K-H solution in L-IR and O-IR groups.In L-IR+ Sev and O-IR+ Sev groups, hearts were subjected to 3 cycles of 5-min perfusion with sevoflurane-containing K-H solution(final concentration 0.6 mmol/L)and 5-min washout, and then hearts were subjected to global ischemia for 25 min, followed by 60-min reperfusion.Left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), and the maximum rate of increase or decrease in left ventricular pressure (±dp/dtmax) were recorded at the end of reperfusion.Hearts were obtained at the end of reperfusion for determination of myocardial infarct size and expression of MIF (by Western blot). Results Compared with Lean group, the weight, blood glucose, levels of plasma total cholesterol, triglyceride, insulin and leptin were significantly increased in Obese group (P 0.05). Conclusion The mechanism by which obese abolishes sevoflurane preconditioning-induced cardioprotection may be related to inducing MIF over-expression in mice. Key words: Macrophage migration-inhibitory factors; Obesity; Anesthetics, inhalation; Ischemic preconditioning; Myocardial reperfusion injury

External quality assessment schemes for glucose measurements in Germany: factors for successful participation, analytical performance and medical impact.

Determination of blood glucose concentration is one of the most important measurements in clinical chemistry worldwide. Analyzers in central laboratories (CL) and point-of-care tests (POCT) are both frequently used. In Germany, regular participation in external quality assessment (EQA) schemes is mandatory for laboratories performing glucose testing. Glucose testing data from the two German EQAs "Reference Institute for Bioanalytics" (RfB) and "INSTAND - Gesellschaft zur Förderung der Qualitätssicherung in medizinischen Laboratorien" (Instand) were analyzed from 2012 to 2016. Multivariable odds ratios (OR) for the probability to reach a "good" result were calculated. Imprecision and bias were determined and clinical risk of measurement errors estimated. The device employed was the most important variable required for a "good" performance in all EQAs. Additional participation in an EQA for CL automated analyzers improved performance in POCT EQAs. The reciprocal effect was less pronounced. New participants performed worse than experienced participants especially in CL EQAs. Imprecision was generally smaller for CL, but some POCT devices reached a comparable performance. Large lot-to-lot differences occurred in over 10% of analyzed cases. We propose the "bias budget" as a new metric to express the maximum allowable bias that still carries acceptable medical risk. Bias budgets were smallest and clinical risks of errors greatest in the low range of measurement 60-115 mg/dL (3.3-6.4 mmol/L) for most devices. EQAs help to maintain high analytical performances. They generate important data that serve as the foundation for learning and improvement in the laboratory healthcare system.

Noninvasive Determination of Blood Glucose Concentration by Comparing the Eardrum and Head Skin Temperatures

A noninvasive method for determination of blood glucose concentration from the eardrum and head skin temperatures was suggested and tested. The method takes into account the effects of food intake and ambient temperature on blood glucose concentration. The method successfully underwent tests in healthy subjects and patients with diabetes mellitus.

Non-invasive Optical Techniques for determination of blood Glucose levels: A Review Article

This article reviews the development of non-invasive optical techniques for determination of blood glucose concentrations in diabetic patients. Early diagnosis and daily management are essential for ensuring the healthy life of diabetic patients. The determination of blood glucose concentration with common devices involves the chemical analysis of blood samples, which are obtained by pricking the finger or extracting blood from the forearm. Pain, discomfort, and inconvenience, associated with current invasive methods, have necessitated the investigation of non-invasive measurement techniques. Non-invasive monitoring of blood glucose level offers several advantages, including absence of pain and biohazard materials, non- exposure to sharp objects, increased testing frequency and consequently, tighter control of glucose concentration. Considering these potential advantages commercialization of non-invasive glucose monitoring devices has become a subject of increasing interest. Several optical technologies have the potential to provide viable noninvasive measuring devices. this review study aimed to describe the major optical technologies for noninvasive glucose monitoring and compare their advantages and disadvantages. second scenario) better than other methods in presence of a typically low false positive rate equal to 3%.

Evaluation of a portable glucose meter for use in cattle and sheep

In farm animal practice, determination of blood glucose concentration under field conditions is often necessary. As there is no portable glucose meter device developed for use in farm animals, the analytical accuracy of a portable glucometer designed for people was evaluated for its use in cattle and sheep. Blood samples from 90 cattle and 101 sheep were used in the study. Glucose concentration was determined in whole blood immediately after blood collection from the jugular vein with the One Touch Vita portable glucometer and in serum with an enzymatic colorimetric method. The agreement between methods was assessed by Passing and Bablok regression analysis. The precision and the accuracy of the measurements were determined using the concordance correlation coefficient. There was a strong linear relationship between the glucose values obtained using the portable glucometer and those obtained by the bench method in both cattle and sheep. Precision was 95% for cattle and 88% for sheep, whereas accuracy was 92% and 99%, respectively. The mean glucose values obtained using the portable glucometer were significantly lower by 8.3% in cattle and 3.2% in sheep than those determined by the bench method. The One Touch Vita portable glucometer can be used in clinical practice to determine blood glucose concentrations in cattle and sheep, but reference intervals (RI) must be corrected to allow for negative bias. Based on these equations the RI for blood glucose in cattle and sheep using the portable glucometer were corrected to 1.84-4.17 and 2.41-4.35 mmol/L, respectively.

Intraoperative blood glucose concentration fluctuation is closely related to short-term clinical outcomes in patients after off-pump coronary artery bypass graft

Objective To investigate the effect of intraoperative fluctuation in blood glucose concentration (BGCF) on short-term clinical outcomes in patients after off-pump coronary artery bypass graft (CABG) .Methods Two hundred and fourteen ASA Ⅰ -Ⅲ patients ( NYHA grade Ⅰ -Ⅲ ) of both sexes aged 18-64 yr with body mass index 23-29 kg/m2 underwent elective off-pump CABG. Their left ventricular ejection fraction was ≥30% .Blood samples were obtained once an hour for determination of blood glucose concentration (BGC) between 10 min after induction of anesthesia and 10 min after closure of sternum. The maximum and minimum BGCs were record-ed . Intraoperative BGCF was defined as the difference between the maximum and minimum BGCs. Other factors which may influence clinical outcome were also recorded, including prolonged ICU stay ( ≥24 h), prolonged me-chanical ventilation ( ≥12 h) , postoperative complications (cardiac insufficiency secondary to operation, arrhyth-mia, myocardial infarction, respiratory insufficiency, stroke, infection, pleural effusion and surgical bleeding) and prolonged postoperative hospital stay ( ≥ 7 d) . The patients were divided into 2 groups using intraoperative BGCF 400 mg/L as cutoff point: group L < 400 mg/L and group H ≥400 mg/L. Receiver operating characteristic (ROC)curve was used to evaluate if intraoperative BGCF was a good index of postoperative outcomes. Results The area under the ROC curve of intraoperative BGC against prolonged ICU stay was 0. 804 (0.739-0. 869), against prolonged mechanical ventilation 0. 604 ( 0.415-0.793 ), against postoperative complications 0.801 ( 0.720-0. 882 )and against postoperative hospital stay 0.615 (0.523-0.707). The duration of ICU stay was significantly longer and the incidences of complications and prolonged postoperative hospital stay were higher in group H than in group L (P < 0.01). Conclusion Intraoperative BGCF is closely related to postoperative outcomes in patients after offpump CABG. The patients with the BGC≥400 mg/L has a poor prognosis. Key words: Blood glucose; Prognosis; Coronary artery bypass, off-pump

Determination of blood glucose concentration by back propagation neural network

This paper presents a supervised backpropagation neural (BPN) network for the determination of blood glucose in diabetic patients. Non- invasive measurement of blood glucose concentration based on reflected laser beam from the index finger has been reported in this paper. This method depends on Helium-Neon (He-Ne) gas laser operating at 632.8 nm wave length. During measurement the index finger is placed in the laser beam transceiver unit, the reflected optical signal is converted into its corresponding electrical signal and the obtained signal is processed by the neural network which presents the results in the form of blood glucose concentration. Diabetes database used for empirical comparisons and the results are shown that BPN network performs better. Keywords: Artificial neural network, diabetes mellitus, non-invasive measurement, supervised learning.

Determination of blood glucose concentration by back propagation neural network

This paper presents a supervised backpropagation neural (BPN) network for the determination of blood glucose in diabetic patients. Non- invasive measurement of blood glucose concentration based on reflected laser beam from the index finger has been reported in this paper. This method depends on Helium-Neon (He-Ne) gas laser operating at 632.8 nm wave length. During measurement the index finger is placed in the laser beam transceiver unit, the reflected optical signal is converted into its corresponding electrical signal and the obtained signal is processed by the neural network which presents the results in the form of blood glucose concentration. Diabetes database used for empirical comparisons and the results are shown that BPN network performs better.

S2057 Diabetes-Induced Changes in the Expression of Proteins Involved in the Regulation of Sustained Mlc 20 Phosphorylation and cGMP Levels in Gastrointestinal Smooth Muscle

The gastrointestinal complications of diabetes mellitus include nausea, vomiting, increase in intragastric pressure and delay in gastric emptying. Several studies showed that the changes in gastric emptying in diabetes are associated with the loss of enteric neurons and interstitial cells of Cajal, and dysfunction of neuronal nitric oxide synthase activity. We have previously shown that in gastrointestinal smooth muscle sustained MLC20 phosphorylation and contraction are dependent on inhibition of MLC phosphatase, which is mediated by RhoA-dependent pathway involving phosphorylation of MYPT1 (at Thr696) by Rho kinase and CPI-17 (at Thr38) by PKC. Smooth muscle relaxation is dependent on stimulation of cAMP and cGMP levels and activation of cAMPand cGMP-dependent protein kinases. The levels of cAMP and cGMP are regulated mainly by phosphodiesterase (PDE) 4D5 and PDE5, respectively. We hypothesized that diabetes induces changes in the expression of proteins involved in the maintenance of smooth muscle tone and regulation of cGMP levels. Aim. To determine the expression of PDE5, CPI-17 and Rho kinase as well as agonist-induced Rho kinase activity in gastric smooth muscle from control and diabetic animal models.Methods. Gastric smooth muscle was isolated from spontaneously type II diabetic ob/ob mice and type I diabetic rats. Type I diabetes was induced in rats by intravenous injection of streptozotocin. The rats were kept for 9 weeks and induction of diabetes was ascertained by the determination of blood glucose concentrations. Expression of CPI-17, Rho kinase and PDE5 was measured by immunoblot analysis and acetylcholine-induced Rho kinase activity was measured by immunokinase assay. Results. Expression of CPI-17, Rho kinase and PDE5 are significantly higher in gastric smooth muscle from both models of diabetic animals than from control animals. Consistent with the increased expression of Rho kinase, acetylcholine-induced Rho kinase activity was also significantly higher in smooth muscle from both models of diabetic animals than from control animals. Conclusion. This study identified mechanisms for increased smooth muscle tone and decreased smooth muscle relaxation in diabetes that are directly attributable to changes in smooth muscle physiology. The mechanisms involved increased expression of proteins involved in the regulation of sustained MLC20 phosphorylation (CPI-17 and Rho kinase) and cGMP levels (PDE5). Upregulation CPI-17 and Rho kinase could contribute to increased intragastric pressure, whereas upregulation of PDE5 could contribute to rapid hydrolysis of cGMP and decreased relaxation leading to delay in gastric emptying.

Agreement between point‐of‐care glucometry, blood gas and laboratory‐based measurement of glucose in an equine neonatal intensive care unit

AbstractObjective: To test the agreement between 3 common methods of glucose measurement in a population of critically ill foals presenting to a neonatal intensive care unit.Design: Prospective clinical study.Setting: University large animal hospital neonatal intensive care unit.Animals: Sequentially admitted critically ill neonatal foals &lt;30 days of age.Interventions: Venous blood obtained from a jugular vein was used for determination of blood glucose concentration using point‐of‐care (POC) glucometry (GLU), a laboratory chemistry technique (CHEM) and a multi‐electrode blood gas analyzer (BG). Paired data were compared using Lin's concordance correlation, Pearson's correlation and robust regression. Bias and limits of agreement were investigated using the technique of Bland and Altman.Measurements and main results: Concordance was significant for all comparisons and was strongest for CHEM‐BG while weakest for GLU‐BG. Pearson's correlation was excellent for all comparisons: CHEM‐BG, 0.98; GLU‐BG, 0.94; GLU‐CHEM, 0.96. All comparisons had significant robust regression coefficients: CHEM‐BG, 0.99; GLU‐BG, 0.80; GLU‐CHEM, 0.79. For Bland–Altman analysis, mean differences (mean±SD, 95% limits of agreement) were: GLU‐BG (−33±18 mg/dL, −68.6 to 1.5); GLU‐CHEM (−20±16 mg/dL, −51.0 to 10.9); CHEM‐BG (13±11 mg/dL, −8.7 to 34.7).Conclusions: This study demonstrates that glucometry has less than ideal agreement with a laboratory standard and another POC test, blood gas analysis. These differences may be clinically important and decisions regarding management of glucose concentrations in critically ill foals should be made with these differences in mind.

Hereditary hyperglycaemia and pancreatic degeneration in Guinea pigs

In this manuscript we describe two closely related inbred guinea pig strains, maintained at the Central Animal Facility of the Hannover Medical School, which develop a Type 2 diabetes mellitus-like syndrome. Both strains are characterised by a high incidence of hyperglycaemia, early onset and manifestation of hyperglycaemia (3 months of age), non-inflammatory chronic vacuolary degeneration of ß-cells in the pancreas, and an opacity of the optic lens. The development of diabetes was monitored by determination of blood glucose concentration and light microscopy of various organs. The measurement of serum insulin revealed a severe decrease. Tentative treatment was done by implantation of a sustained release insulin implant, but showed no impact on the blood glucose concentration within an observation period of 8 weeks. Further functional and genetic studies are needed to verify whether these two strains of guinea pigs make valuable animal models for studying the interacting factors leading to Type 2 diabetes mellitus.

Reliability assessment of glucose measurement by HemoCue analyser in a neonatal intensive care unit

Rapid and reliable bed-side determination of blood glucose concentration is very important in the management of acutely ill infants and especially in premature newborns. HemoCue is an easy-to-use glucose analyser. The aim of the present study was to examine the usefulness of the HemoCue glucose analyser compared to a reference plasma glucose method (SYS, BM/Hitachi 747/737) in a neonatal intensive care unit (NICU). Seventy-eight consecutive neonates admitted to our NICU were enrolled in the study. At the time of the study all patients were grouped according to nutritional management (parenteral or enteral nutrition), haematocrit values and birth weight. The effects of feeding management, haematocrit values, and birth weight on accuracy and precision of the device were evaluated. Overall data linear regression analysis yielded an r-value of 0.905 and the Bland-Altman method demonstrated that HemoCue overestimates plasma glucose by 0.932 mmol/L. Evaluation of our data by receiver operating characteristic curve demonstrated 100% sensitivity cutoff at 4.1 mmol/L. HemoCue cannot be used satisfactorily in the management of glycaemia in the NICU. In the preterm population, birth weight had a dramatic influence on HemoCue accuracy. Low haematocrit and parenteral feeding further contributed to a decrease in the accuracy of this device.

AMP-activated Protein Kinase α2 Activity Is Not Essential for Contraction- and Hyperosmolarity-induced Glucose Transport in Skeletal Muscle

To examine the role of AMP-activated protein kinase (AMPK) in muscle glucose transport, we generated muscle-specific transgenic mice (TG) carrying cDNAs of inactive alpha2 (alpha2i TG) and alpha1 (alpha1i TG) catalytic subunits. Extensor digitorum longus (EDL) muscles from wild type and TG mice were isolated and subjected to a series of in vitro incubation experiments. In alpha2i TG mice basal alpha2 activity was barely detectable, whereas basal alpha1 activity was only partially reduced. Known AMPK stimuli including 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICAR), rotenone (a Complex I inhibitor), dinitrophenol (a mitochondrial uncoupler), muscle contraction, and sorbitol (producing hyperosmolar shock) did not increase AMPK alpha2 activity in alpha2i TG mice, whereas alpha1 activation was attenuated by only 30-50%. Glucose transport was measured in vitro using isolated EDL muscles from alpha2i TG mice. AICAR- and rotenone-stimulated glucose transport was fully inhibited in alpha2i TG mice; however, the lack of AMPK alpha2 activity had no effect on contraction- or sorbitol-induced glucose transport. Similar to these observations in vitro, contraction-stimulated glucose transport, assessed in vivo by 2-deoxy-d-[(3)H]glucose incorporation into EDL, tibialis anterior, and gastrocnemius muscles, was normal in alpha2i TG mice. Thus, AMPK alpha2 activation is essential for some, but not all, insulin-independent glucose transport. Muscle contraction- and hyperosmolarity-induced glucose transport may be regulated by a redundant mechanism in which AMPK alpha2 is one of multiple signaling pathways.

Osteopenia: a bone disorder associated with diabetes mellitus

Although osteopenia has been associated with human diabetes mellitus, the pathogenesis of diabetic osteopenia is unclear. In the present study, we evaluated the effect of diabetes on histomorphometry, bone mineral density (BMD)-measured by dual-energy X-ray absorptiometry (DXA)-and biomarkers of bone metabolism in rats up to 120 days after the onset of experimental diabetes. Female Wistar rats with a regular estrous cycle were randomly divided into two groups: control rats (n = 15) and diabetic rats without insulin treatment (n = 25). Diabetes was induced by injection of alloxan and was confirmed by the determination of blood glucose concentration (>250 mg/dl). The results revealed an approximate threefold increase of femoral trabecular distance in diabetic rats compared to controls. Conversely, trabecular thickness and bone trabecular volume were reduced twofold and 77%, respectively. BMD in both the metadiaphyseal region and total area of the femur was found to be clearly reduced in diabetic animals, with no significant differences between the groups. Serum alkaline phosphatase (ALP) and tartarate-resistant acid phosphatase (TRAP) activities showed significant six- and twofold increases, respectively, in diabetic rats. There were significant decreases in serum calcium and albumin concentrations in diabetic rats, but no difference was observed in serum magnesium, phosphorus, or creatinine concentrations between the groups. Overall, our findings support the conclusion that the diabetic state is associated with alterations in bone turnover, resulting in the development of osteopenia, which is related to the time of evolution of the disorder.

A rapid method for determination of blood glucose concentration in cattle

Objective To determine an accurate rapid method for determination of blood glucose concentration in cattle under field conditions. Design Prospective, randomized, controlled trial. Animals 62 clinically normal Holstein cattle: 34 cows and 28 calves. Procedure Glucose concentrations in venous blood samples were measured in duplicate using a rapid, dryslide chemistry technique for determination of blood glucose concentration and a laboratory-based method for determination of plasma glucose concentration. Analyses of variance were used to determine whether the relationship between results of the 2 methods was affected by the status of the animals (cows vs calves) or the PCV of the blood samples. Simple linear regression was performed to determine the correlation between the 2 methods and the slope, intercept, and residual error variance of the relationship between the methods. Results There was a significant linear relationship between the 2 methods throughout the range of glucose concentrations. Mean difference between results of the 2 methods (results for laboratory-based method – results for rapid method) was 12.95 mg/dl (SD, 7.20 mg/dl). The PCV did not affect the relationship, and there was no difference between results of the 2 methods for cows versus calves. Correlation between means of the duplicative values determined by use of the 2 methods was high (r = 0.9462). Clinical Implications The good correlation between the 2 procedures and the comparable precision estimates (coefficient of variation, 7.17% for laboratory-based method; coefficient of variation, 10.11 % for rapid method) indicates that using the rapid method to measure blood glucose concentration is valid in cows and calves. (J Am Vet Med Assoc 1996;208:707–710)

Catecholamines stimulate the synthesis and release of insulin-like growth factor binding protein-1 (IGFBP-1) by fetal sheep liver in vivo.

In fetal sheep, prolonged hypoxia (for 24 h) induced by a reduction in maternal uterine artery blood flow, increases insulin-like growth factor binding protein-1 (IGFBP-1) levels and decreases IGFBP-2 levels in the plasma, with corresponding changes in messenger RNA (mRNA) levels in the liver. Since IGFBP-1 synthesis in liver cells in vitro is stimulated by compounds that increase intracellular cAMP concentrations, we hypothesized that the increased IGFBP-1 synthesis during prolonged hypoxemia may be induced by circulating catecholamines, that are released during hypoxia, and that elevate fetal liver cAMP levels. Our aim was to determine the effect of 24-h catecholamine infusions on the synthesis and release of IGFBP-1 and IGFBP-2 in fetal sheep. Vascular catheters were implanted into fetuses at 110-115 days gestation in 14 pregnant ewes. After a 5-day recovery period, fetuses received a 24-h infusion of either norepinephrine (1 micrograms/kg.min, n = 5), epinephrine (0.25 micrograms/kg.min, n = 5), or vehicle (normal saline, n = 4). Fetal carotid arterial samples were collected at specified intervals throughout the infusion for the determination of blood glucose concentrations, plasma catecholamine concentrations by HPLC, insulin, and glucagon concentrations by RIA, and IGFBP levels by Western ligand blotting. After 24 h, the ewe and fetus were killed and selected fetal tissues (liver and kidney) were collected, and analyzed for IGFBP mRNA levels by northern blotting followed by laser densitometric quantification. Plasma catecholamine concentrations were increased in treated fetuses to levels that may be expected in fetuses subjected to prolonged hypoxia. In epinephrine and norepinephrine infused fetuses, blood glucose and plasma glucagon concentrations were increased significantly, whereas plasma insulin concentrations were decreased significantly. Norepinephrine and epinephrine infusions increased IGFBP-1 levels significantly (2- to 5-fold) in fetal plasma within 8-12 h, and the time course pattern of elevation of plasma IGFBP-1 levels was similar to that observed in prolonged hypoxia. After 24 h of either norepinephrine or epinephrine infusion, IGFBP-1 mRNA levels in the liver of fetuses were increased significantly (5- to 7-fold) compared to those of vehicle infused fetuses. IGFBP-2, -3, and -4 levels in fetal plasma were not affected by either infusion, nor were IGFBP-2 mRNA levels in fetal liver and kidney.(ABSTRACT TRUNCATED AT 400 WORDS)