Objective—To determine the effects of extended
experimental hepatic blood flow occlusion (ie, portal
triad clamping [PTC]) in dogs by measuring acid-base
status and plasma lactate concentrations in arterial,
mixed venous, and portal blood and evaluating the
relationship between metabolic and concurrent
Animals—6 healthy Beagles.
Procedure—During anesthesia with isoflurane, cardiac
output and arterial blood pressure were measured.
Arterial, mixed venous, and portal blood samples
were collected simultaneously for blood gas
analyses and plasma lactate measurements before
PTC and at 8-minute intervals thereafter.
Results—PTC resulted in severe hemodynamic and
metabolic alterations. Eight minutes after PTC, significant
decreases in cardiac index from a baseline value
of 3.40 ± 0.27 to 1.54 ± 0.26 L/min/m2 and in mean
arterial blood pressure from a baseline value of 74 ± 6
to 43 ± 6 mm Hg were recorded. After PTC, results
indicative of lactic acidosis were found in portal blood
at 16 minutes, in mixed venous at 32 minutes, and in
arterial blood at 48 minutes. Significant differences in
measured variables were also found between arterial
and portal blood samples, between mixed venous
and portal blood samples, and between arterial and
mixed venous blood samples after PTC, compared
with differences at baseline.
Conclusions and Clinical Relevance—Analysis of
mixed venous blood is preferable to analysis of arterial
blood in the assessment of metabolic derangement.
In a clinical setting, occluded portal blood is
released to the systemic circulation, and the degree
of reperfusion injury may depend on the metabolic
status of pooled portal blood. (Am J Vet Res 2003;64:599–608)
OBJECTIVE To determine the plasma total antioxidant capacity, erythrocyte superoxide dismutase activity, whole blood glutathione peroxidase activity, and plasma coenzyme Q10 (CoQ10) concentration in dogs with various stages of cardiovascular diseases and in healthy dogs; assess the influence of cardiac treatment on the levels of antioxidant variables, plasma CoQ10 concentration, and serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration, and determine any correlation between the disease severity (NT-proBNP concentration) and antioxidant variables or CoQ10 concentration.
ANIMALS 43 dogs with various types and stages of cardiovascular diseases (congenital and acquired) and 29 healthy dogs.
PROCEDURES Blood samples were collected from all dogs for spectrophotometric assessment of antioxidant variables. Plasma CoQ10 concentration was determined with a high-performance liquid chromatography–atmospheric pressure chemical ionization–tandem mass spectrometry method. Serum NT-proBNP concentration was measured with an ELISA.
RESULTS Values for antioxidant variables did not differ among groups of dogs with cardiovascular diseases, regardless of disease stage or treatment. Plasma CoQ10 concentration was significantly increased in treated dogs with congestive heart failure (CHF), compared with untreated patients. However, plasma CoQ10 concentration did not differ among heart failure classes. A significant, negative correlation between serum NT-proBNP and plasma CoQ10 concentrations was identified in treated CHF-affected dogs, suggesting that low plasma CoQ10 concentration may be associated with increased severity of CHF.
CONCLUSIONS AND CLINICAL RELEVANCE The antioxidant variables evaluated were not altered in dogs with CHF, regardless of cardiac disease stage or treatment. Further investigation into the possible effects of CoQ10 supplementation in dogs with advanced stages of CHF is warranted.