Objective—To determine the full-length complementary
DNA (cDNA) sequence of equine erythropoietin
(EPO) and to develop region-specific antibodies to differentiate
equine EPO (eEPO) and human EPO
Sample Population—RNA and lysate extracted from
renal tissues of an adult Thoroughbred.
Procedure—Full-length cDNA was determined by
use of a reverse transcriptase-polymerase chain reaction
assay and a rapid amplification of cDNA ends
method. The deduced amino acid sequence was compared
with sequences of EPO reported for other
species. Furthermore, 4 synthetic peptides were
designed in 2 distinctive parts of the eEPO and hEPO
amino acid sequences to obtain antibodies specific
for eEPO and hEPO. Specificity of the antibodies was
tested against supernatant of homogenized equine
kidney and recombinant hEPO (rhEPO) by use of
western immunoblotting techniques.
Results—Analysis of the 1,181 bp in the nucleotide
sequence revealed that eEPO was a residue of 192
amino acids. Similarity of eEPO with amino acid
sequences of EPO from other species was 81.0% to
90.6%. Antibodies were specifically recognized by
eEPO or rhEPO molecules. Anti-hEPO (161 to 165)
antibody specifically recognized rhEPO. In contrast,
anti-eEPO (133 to 144) antibody reacted with the
equine kidney lysate.
Conclusions and Clinical Relevance—We determined
the cDNA and amino acid sequence of eEPO
and developed region-specific antibodies that specifically
recognized eEPO or rhEPO. These antibodies
may be useful in distinguishing rhEPO from eEPO in
a test to detect the misuse of rhEPO in racehorses.
( Am J Vet Res2004;65:15–19)
Objective—To determine the pharmacokinetics and tissue distribution of minocycline in horses.
Animals—5 healthy Thoroughbred mares for the pharmacokinetic experiment and 6 healthy Thoroughbred mares for the tissue distribution experiment.
Procedures—Each mare was given 2.2 mg of minocycline hydrochloride/kg, IV. Blood samples were collected once before minocycline administration (0 hours) and 10 times within 48 hours after administration in the pharmacokinetics study, and 24 tissue samples were obtained at 0.5 and 3 hours in the distribution study.
Results—No adverse effects were observed in any of the mares after minocycline administration. The mean ± SD elimination half-life was 7.70 ± 1.91 hours. The total body clearance was 0.16 ± 0.04 L/h/kg, and the volume of distribution at steady state was 1.53 ± 0.09 L/kg. The percentage of plasma protein binding was 68.1 ± 2.6%. Plasma concentration of free minocycline was 0.12 μg/mL at 12 hours. Minocycline was not detected in brain tissue, CSF or aqueous humor at 0.5 hours; however, it was found in all tissues, except in the aqueous humor, at 3 hours.
Conclusions and Clinical Relevance—Clearance of minocycline in healthy mares was greater than that reported for humans. For effective treatment of infections with common equine pathogens, it will be necessary to administer minocycline at a dosage of 2.2 mg/kg, IV, every 12 hours. This drug could be useful for infections in many tissues, including the CNS. The pharmacokinetic and tissue distribution data should aid in the appropriate use of minocycline in horses. (Am J Vet Res 2010;71:1062–1066)