Exercise and epinephrine affect equine leukocytes distribution and gene expression in a distinct but closely related pattern

in Veterinary Clinical Pathology (2011, December), 40(4), 583-584

Background: In horses-athletes, exercise has been shown to be an important regulator of immune cells and their functions, and catecholamines to be essential components of the physiological response to ... [more ▼]

Background: In horses-athletes, exercise has been shown to be an important regulator of immune cells and their functions, and catecholamines to be essential components of the physiological response to exercise. Objectives: The purpose of the present study was to compare immunological reactions and molecular events during exercise and epinephrine infusion. Methods: Horses were submitted to exercise or epinephrine infusion for 10 min. Blood samples were collected at T0, T5, Tl0, T20 and T40 min for biochemistry and haematology at T0 and T20 min for RNA extraction and microarray analysis. Results: In both protocols, packed-cell-volume and neutrophils peaked at T5 and T10, and returned to baseline at T40. Lymphocytes increased at T5 with exercise and at T20 with epinephrine and then remained high until the end of the protocols. Between T0 and T20, 55 probes, coding for 25 genes, and 19 probes, coding for 11 genes, were differentially regulated with epinephrine and exercise respectively (P<0.001). Ten of the genes over-expressed with epinephrine were related to inflammatory response and leukocytes trafficking and activation. Among the genes with the highest significant fold changes following exercise were FOS, DUSP-1 and CXCL1. FOS was over-expressed in both conditions. Among genes differentially regulated, Ingenuity software identified 3 overlapping functional networks with epinephrine and 1 functional network with exercise that overlapped the 3 epinephrine networks. Conclusions: Circulating leukocytes distribution and gene expression are rapidly affected following exercise and epinephrine infusion. Distinct but closely-related sets of gene activities were shown to be altered with exercise and epinephrine, with lesser changes in the immunological pattern with physical stress than epinephrine alone, arguing for compensatory mechanisms in exercise. [less ▲]

Relationship between haptoglobin, serum amyloid A, and clinical status in a survey of dairy herds during a 6-month period

in Veterinary Clinical Pathology (2006), 35(2), 188-193

Haptoglobin and serum amyloid A are major acute phase proteins in cattle. Dairy cattle often develop pathologic conditions in the peripartum period; acute phase proteins may be useful in their diagnosis ... [more ▼]

Haptoglobin and serum amyloid A are major acute phase proteins in cattle. Dairy cattle often develop pathologic conditions in the peripartum period; acute phase proteins may be useful in their diagnosis. Objectives: The purpose of this study was to compare the accuracy of serum haptoglobin (Hp) and serum amyloid A (SAA) concentrations with clinical health status for diagnosing disease during the peripartum period in dairy cattle. Methods: Dairy cows from 4 herds were evaluated every 15 days over a 6-month period. Health status was determined by thorough clinical examination. Haptoglobin and SAA concentrations were measured in serum using validated methods and the results were classifed as positive or negative based on defined cutoff points. Disease prevalence, sensitivity, and specificity were compared using clinical examination as the gold standard. Results: A total of 1896 samples from 158 cows were analyzed. Significant increases in mean Hp and SAA concentrations were observed in the week following parturition in both primiparous and multiparous cows, although high interindividual variability was observed. Both Hp and SAA had low sensitivity but higher specificity in determining disease status compared with clinical examination. Increased concentrations of Hp and SAAwere found in ,10% of samples from clinically healthy cows, except in the week after parturition. Conclusions: Haptoglobin and serum amyloid A should be used with caution as markers of inflammation in the week after calving. Poor sensitivity in other postpartum periods could be related to the higher incidence of chronic (vs acute) inflammation. Haptoglobin may be appropriate for routine screening, but further work needs to be done to assess its value as an indicator of herd health. [less ▲]