Variability of blood biochemical parameters and establishment of reference intervals in preclinical studies. Part 11: dogs

Abstract

Dogs are a common in vivo test system in preclinical studies due to the relatively large body size sufficient for surgical manipulations, as well as the pathophysiology of various diseases similar to humans. A separate point of application of the animal species in question in preclinical studies is the study and therapy of oncological diseases. The aim of the work was to create its own database of reference intervals of biochemical blood parameters of Beagle dogs. These norms are necessary in preclinical studies when asses­sing the state of animal health, monitoring the formed pathological model, as well as checking the safety of the studied drugs. Biological samples used for the formation of reference intervals were obtained from intact animals in research and manufacturing company “Home оf Pharmacy”. All manipulations and experiments carried out were approved by the bioethical commission. The study included 56 males and 48 females. The age of the animals corresponded to the range of 10–18 months, the body weight of females was 7–11 kg, and males 8–14 kg. In order to implement a uniform approach when creating reference intervals, all manipulations were carried out under the same conditions. For the study, blood was used, which was taken from the lateral subcutaneous vein of the leg of the studied animals on an empty stomach, without sedation and anesthesia. The following parameters were recorded in the blood serum of animals: creatinine, urea, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, cholesterol, triglycerides, total protein, albumin, glucose, creatine kinase, lactate dehydrogenase and total bilirubin, the albumin-globulin coefficient was calculated. Statistical outliers were estimated using the Tukey method, the type of distribution was determined using the Shapiro—Wilk criterion, paired comparisons between animals of different sexes were carried out using the Mann—Whitney U-test and the Student t-test. The obtained ranges of values of males and females correlated with each other for all the considered indicators, no statistical difference was revealed. When comparing the obtained intervals with the reference ranges of dogs from other literature sources, it was shown that, in general, the ranges of the considered indicators are similar, but there are also differences that can be explained by a wide list of factors. These include the image of keeping animals, as well as the preanalytical and analytical stages of the study. A comparative analysis of the interindividual variability of the biochemical parameters of the blood of dogs and humans showed the presence of some species differences that need to be taken into account in experimental activities.