The Progression of Glucose Consumption by Red Blood Cells Once Extracted FromDomestic Canines, Canis familiarisJeanette Coffin and Nadine MuallemDepartment of Biological ScienceSaddleback CollegeMission Viejo, CA 92692The integrity of uncentrifuged specimens for diagnostic evaluation is acontinued problem amongst clinical laboratories. Prolonged contact of red bloodcells with other analytes may be detrimental to the stability of the sample beinganalyzed. It is pertinent that a patient receives the utmost ideal medical treatmentfor their condition. If blood results are compromised due to ongoing metabolism byerythrocytes, improper medical treatment may ensue. Medical conditions such asdiabetes and hypoglycemia rely directly on diagnostic evaluation. To determine ifRBCs continued to consume glucose, uncentrifuged, canine blood specimen’sglucose levels were tested at intervals of 0, 1, 3, 6, 9 and 12-hours post venipuncture.Samples remained in BD microtainer tubes containing lithium heparin to preventcoagulation. The results yielded were significant in the depletion of glucose from theinitial blood draw beyond the third hour (p0.05 ANOVA). However, furtherstatistical analysis (Bonferroni post-Hoc) revealed there was not a remarkabledecrease in glucose from the initial venipuncture to the first hour (p0.05).IntroductionBlood is comprised of a multitude of analytes (such as sugars, clotting factors,hormones, and other nutrients), platelets, red blood cells, and white blood cells. Duringthe lifespan of the red blood cell, it’s job is not only to carry oxygen rich hemoglobin tothe capillaries, but also includes, production of various chemical compounds from theabsorption or consumption of other chemicals in the surrounding environment (Deaton etal. 1984). Red blood cells (also called erythrocytes) continue consumption ofsurrounding analytes even after blood specimens have been extracted from their hostenvironment (Zehnder et. al. 2008). Therefore, accuracy is key when evaluating apatient’s blood for any type of diagnostic testing. Blood samples from an individual, mustbe properly stored and maintained in order to obtain an accurate evaluation of chemicalanalyses (Hrubec et al. 2002). The cells must be separated from the plasma or serum toprevent continued metabolism (Blick and Boyanton 2002). Diagnostic results of a patient’s blood play a vital role in the management of theirmedical treatment (Herbert et al. 2005). For instance, diabetes and hypoglycemia areserious medical conditions that directly rely on accurate analysis of glucose levels withinthe bloodstream. Differentials in blood glucose levels are also known to accompanycritical conditions, such as, stroke, shock and sepsis. Even glucose concentrations withinthe blood directly coincide with glucose concentrations in cerebrospinal fluid and can beused to diagnose bacterial meningitis (Dujmovic and Deisenhammer 2010). In a study byChristopher and O’Neill (2000), human blood was sampled and glucose depletion wassignificantly noted in vitro when not properly stored. The rate of consumption of variousanalytes by RBCs is dependent on the makeup of the blood (Han et. al. 2003). Usingblood from ten, randomly selected, healthy canines, Canis familiaris, the study tested thehypothesis that over a period of twelve hours glucose concentrations would notablydecrease when blood samples were left uncentrifuged.Materials and MethodsTen privately owned domestic canines, Canis familiaris, were used in this studywith signed authorization from their owner. The name, mass, species, age, and sex wasrecorded for each dog. All testing took place at Animal Urgent Care of South OrangeCounty, (Mission Viejo, CA), between November 2, 2011 to November 7, 2011. Threemilliliters of blood was obtained from the jugular vein of each subject using a sterile 6.0-mL syringe with an attached 22-gauge needle. Immediately post draw, an initial packedcell volume (PCV) was measured by placing a small portion of the blood into twoheparinized hematocrit tubes then centrifuged for three minutes. The PCV measurementwas obtained by then lining a single tube up to a standardized hematocrit chart. Thesecond hematocrit tube was to insure for accuracy. PCV values were recorded to thenearest whole percent. Along with PCV values an immediate initial blood glucosereading was performed using the Abaxis, VetScan i-STAT analyzer. The remaining 2.5mLs of blood was then placed into five sterile BD microtainerscontaining lithium heparin, 0.5-mL per tube. Each microtainer was labeled with thesubjects name and hour of testing, and then placed at room temperature (25 C) onto ablood rocker to prevent natural separation of the plasma. The blood glucose levels foreach sample were tested with the VetScan i-STAT analyzer at one, three, six, nine, andtwelve hours post draw. All glucose data were then entered into Microsoft Excel (2008)where statistical analyses were performed. An analysis of variance (ANOVA) and TukeyHSD post hoc analysis were run to determine if there were any statistical differencesbetween the groups.ResultsThe mass for each canine was recorded in kilograms, and a mean mass for thegroup was calculated out to be 15.1-kg. Glucose values for all draws were compiled bythe hour of measurement (1, 3, 6, 9, and 12) and the mean mass for each was calculated.Glucose levels are as follows: Initial draw= 86.0mg/dL (Mean ± SEM), one hour-postdraw= 82.9mg/dL (Mean ± SEM), three-hours post draw= 65.6mg/dL (Mean ± SEM),six-hours post draw= 40.1mg/dL (Mean ± SEM), and nine-hours post draw= 26.1mg/dL(Mean ± SEM). All samples for the twelve-hour post draw registered on the analyzer as 20mg/dL; therefore, with no exact numerical value, the twelve-hour recordings weredisregarded for statistical processing. This indicated that there was an overall decrease inthe amount of glucose from the initial sample. Figure 1 displays the depletion of glucosevalues (mg/dL) over time (hour). An ANOVA confirmed that the decrease in glucose between the groups wassignificant (p 0.05). A Tukey HSD post hoc analysis was run comparing each group tothe other. There were significant differences between each