Objective—To compare characteristics and enzymatic products of leukocytes detected in the skin and laminar tissues of horses administered black walnut heartwood extract (BWHE) and horses administered purified lipopolysaccharide (LPS).
Animals—25 healthy 5- to 15-year-old horses.
Procedures—Horses were randomly assigned to receive LPS (20 ng of O55:B5 Escherichia coli endotoxin/kg; n = 5) IV or 6 L of BWHE (10) or water (control group; 10) via nasogastric intubation. Horses were euthanatized 12 hours after treatment or at onset of Obel grade 1 lameness. Laminar tissue samples and skin samples from the middle region of the neck were harvested at the time of euthanasia. Leukocyte emigration (determined via CD13 immunohistochemical analysis) and matrix metalloproteinase (MMP)-2 and MMP-9 gene expressions and activities (determined via reverse transcription PCR assay and gelatin zymography, respectively) were measured in skin and laminar tissue samples.
Results—Tissues of horses receiving BWHE contained significantly higher numbers of CD13-positive cells and increased MMP-9 gene expression and activity, compared with findings in the other 2 groups. Values for laminar tissue and skin from LPS-treated horses were not increased, compared with findings in the control group, in any experiment.
Conclusions and Clinical Relevance—Results indicated that BWHE administration causes increases in CD13-positive leukocyte numbers and MMP-9 expression and activity in laminar tissue and skin in horses; similar effects were not detected following LPS administration. Leukocyte emigration in horses with experimentally induced endotoxemia and in horses administered BWHE differed markedly, thereby providing additional evidence that the development of laminitis involves more complex mechanisms than endotoxemia-induced leukocyte activation alone.
Objective—To assess serum 17-α-hydroxyprogesterone
(17OHP) and corticosterone concentrations in
dogs with nonadrenal neoplasia and dogs being
screened for hyperadrenocorticism.
Animals—16 clinically normal dogs, 35 dogs with
nonadrenal neoplasia, and 127 dogs with suspected
Procedure—ACTH stimulation tests were performed
in all dogs. Baseline serum cortisol and corticosterone
concentrations were measured in the healthy dogs;
baseline serum cortisol concentration and ACTH-stimulated
cortisol, corticosterone, and 17OHP concentrations
were measured in all dogs. Endogenous plasma
ACTH concentration was also measured before
administration of ACTH in dogs with neoplasia.
Results—In 35 dogs with neoplasia, 31.4% had high
serum 17OHP concentration and 22.9% had high
serum corticosterone concentration. Of the 127 dogs
with suspected hyperadrenocorticism, 59 (46.5%) had
high ACTH-stimulated cortisol concentrations; of those,
42 of 59 (71.2%) and 32 of 53 (60.4%) had high serum
17OHP and corticosterone concentrations, respectively.
Of dogs with serum cortisol concentration within reference
range after ACTH administration, 9 of 68 (13.2%)
and 7 of 67 (10.4%) had high serum 17OHP and corticosterone
concentrations, respectively. In the dogs
with neoplasia and dogs suspected of having hyperadrenocorticism,
post-ACTH serum hormone concentrations
were significantly correlated.
Conclusions and Clinical Relevance—Serum concentrations
of 17OHP or corticosterone after administration
of ACTH may be high in dogs with nonadrenal neoplasia
and no evidence of hyperadrenocorticism. Changes in
serum 17OHP or corticosterone concentrations after
administration of ACTH are proportionate with changes
in cortisol concentration. (J Am Vet Med Assoc 2005;227:1762–1767)