A review of new approaches to assessing hepatic function in animals

Abstract

Although a multitude of effective liver function tests are available for use in animals, a variety of modifications of currently used tests have been recently reported. In addition, newer procedures now used in human medicine may also provide unique insights into assessing and detecting acquired hepatic disorders in animals. Examples of new procedures are: assessing microsomal mixed function oxidase activity by plasma caffeine clearance; estimating the extent of active hepatic fibrogenesis through serum procollagen-III peptide levels; determining hepatic blood flow and functional mass by the galactose elimination capacity; detecting primary hepatocellular cancer through serum or urinary ligandin levels; and to estimate the liver's maximal capacity to excrete indocyanine green independent of blood flow. In evaluating drugs as to their hepatotoxicity, function tests should be included in the liver profile which measure specific metabolic alterations unique to the compound under study.

Liver Enzyme Changes in a Guinea-Pig Model of Facial Eczema (Sporidesmiotoxicosis)

“…The plasma GGT increase followed liver GGT induction; similar variations were also expected for ALP, as induction of both membrane-bound enzymes is well reflected in serum during cholestasis in many species [20], especially in sheep and cattle with facial eczema [2,3,17]. To the best of our knowl edge, there is no information dealing specifi cally with both plasma ALP and GGT in liver induction in guinea pigs; thus, we can not ascertain the reason for this discrep plasma membrane, as in other cholestatic diseases.…”

Clinical Chemical Diagnosis of Diseases Assisted by Logistic Regression Illustrated by Diagnosis of Canine Primary and Secondary Hepatobiliary Diseases

“…Another possibility is to calculate the probability of the suspected disease directly from the analytical results of the parameters, a procedure that can be accomplished by a logistic regression model. In a logistic regression model, independent variables are combined in a linear equation which is used to estimate the logarithm of the probability that an event occurs divided by the probability that it does not (ARMITAGE and BERRY, 1987;KIRKWOOD, 1988). Based on the values of the independent…”

“…In despite of the problems related to the various disease groups of the present study, these findings d o not oppose the findings reported by CENTER et al (1991), who in a study on 170 dogs reported that ASAT and PSBA had the greatest positive predictive values (94.8 Yo and 95.3 %, respectively) for the diagnosis of canine hepatobiliary diseases in general, the positive predictive value being defined as the probability that a patient has a certain disease, when the test is positive. The inclusion of PSBA in the logistic regression model seems reasonable as PSBA primarily indicates disturbance to the functional capacity of the liver, especially disturbance such as a deranged hepatic blood flow (OHKUBO et al, 1984;CORNELIUS, 1987). In contrast, the inclusion of ASAT in the logistic regression model may be surprising, especially as ASAT is located in two cell compartments (i.e.…”

Evaluation of Fasting and Postprandial Total Serum Bile Acid Concentration in Dogs with Hepatobiliary Disorders

“…An explanation for this may be, that the reasons for increases in SBA concentrations to some degree are different from the reasons for increases of the other hepatic tests. For instance, ALAT and ASAT increase mainly due to increased hepatocellular permeability and necrosis, ALP increases mainly due to intrahepatic or extrahepatic cholestasis, and TB increases mainly due to haemolysis, hepatic necrosis, and/ or cholestasis (CORNELIUS, 1987).…”